Diy Ferts - Micro Questions

I have a low tech, lightly planted tank. It has been running for about 10 months now and for the last 6 months or so I have been dosing a liquid fertiliser bought locally. Results have been rather good with increased plant growth but as the water volume is 1500L / 375G it is rather expensive with weekly WC and it is actually keeping me back from doing WC every 4 - 5 days.

This is what I have been dosing:
Micro- Dosing is 0.5cc per 10 liter water
Mg Magnesium 0.24 ppm mg/l
S Sulfur 0.5 ppm mg/l
Zn Zinc 0.03 ppm mg/l
Cu Copper 0.02 ppm mg/l
Mn Manganese 0.06 ppm mg/l
B Boron 0.03 ppm mg/l
Mo Molybdenum 0.005 ppm mg/l
Fe Iron 0.06 ppm mg/l
Macro 1 (Potassium)- Dosing is 1cc per 10 liter water
K Potassium 10 ppm mg/l
S Sulfur 4.5 ppm mg/l
Macro 2 (Phosphorus)- Dosing is 1cc per 10 liter water
K Potassium 0.16 ppm mg/l
P Phosphorus 0.13 ppm mg/l
Cu Copper 0.01 ppm mg/l
Macro 3 (Nitrogen) - Dosing is 1cc per 10 liter water
K Potassium 0.37 ppm mg/l
N Nitrogen 1.82 ppm mg/l
Ca Calcium 0.6 ppm mg/l

1cc = 1ml = 0.033814 US fluid ounce

It is pre-mixed so I didn't control the components or the amount in each bottle. As I have high Nitrate levels I have stopped dosing Nitrogen for the last 1 - 2 months and it seems to have no effect on the plants as there's clearly more than enough already. I have some algae problems but I believe it is due to imbalance between the nutrients with way too much Nitrate. I am about to make a DIY algae scrubber to solve that issue. I am aware that the scrubber will compete with the plants for nutrients but I don't mind dosing a little extra ferts if I have them at low cost.

So I want to mix my own fertilizer. As it is not an option for me to import dry fertilizer from e.g USA I need to see what I can get local.

I have watched the videos on YouTube on DIY Ferts from Aquapros and I think the Macros are quite straight forward so it's more the micro's that may be a challenge.

What's your view on the Micro mix above - in terms of components and also the amounts?
Any other comments and experiences are also very welcome.

 

Most micro mixes are based on plantex csm+b... might want to look it up for reference

 

Most micro mixes are based on plantex csm+b... might want to look it up for reference

Great idea, thanks.

Went to rotalabutterfly.com and checked out CSM+B based on EI and a Fe target of 0.2 and it came back with the following breakdown:
Element ppm/degree
Fe 0.2
Mn 0.057
Cu 0.003
Mg 0.043
Zn 0.011
Mo 0.002
B 0.025
dGH 0.01

These seem to be percentages, except Boron that varies depending on who has added it to the CSM base mix.
Fe 6.53%
Mn 1.87%
Mg 1.40%
Zn 0.37%
Cu 0.09%
Mo 0.05%
B 1.18%

So maybe this will be my target.

 

What's your view on the Micro mix above - in terms of components and also the amounts?

The proportions look good I think. Jocelyn is right that using Plantex CSM+B as a template can be helpful. There are others, such as Rexolin APN and some people try and match Flourish as well.

In terms of its subsidiary components, that can be a challenge, depending on what you can source locally in non-commercial quantities (i.e. trying to find someone who doesn't want to sell you the chemical fertiliser by 25 kg sacks).

Usually it's a combination of the following:

Fe: EDTA (if pH at or below 6.5) or DTPA (if pH above 6.5)
Mn: MnSO4. Usually it's monohydrate for fertilisers, but sometimes only heptahydrate (7H20) is available
Mg: MgSO4. Generally bought as epsom salts, which is MgSO4.7H20
Zn: Either ZnSO4 or ZnO
Cu: CuSO4
Mo: Molybdic acid (written variously as H2MoO4 or MoO3.H2O)
B: Either borax or boric acid

It can be the case that you can buy a locally available trace element mix, and then simply add additional Fe, Mg (and whatever else) to change the proportions a bit. This avoids the necessity of having to purchase all chemical compounds, particularly the CuSO4 and boric acid (on account of their toxicity).

 

I found a pre-mixed micro nutrient pack called NIC spray (despite being dry...) but it is not really meant for "aquaponic" but is fine for hydroponics:

NIC-SPRAY

High Quality Fully water soluble. Chelated Micronutrient Mixture.

Chelate-EDTA : MgO 7.29%, Fe 1.90%, Mn 1.94% Cu 2.08%, Zn 1.90%, B 2.17% Mo 0.024%, NI 0.05%

Unfortunately I don't see it working with the mix listed, also the fact that my PH is 8.2 I think an EDTA chelate will leave very little left for the plants. I think I need a FDTA as minimum but will probably avoid the EDDHA chelate for iron as it seems to stain the water (and everything else) pink even at small doses.

Minnowette What do you think?

 

Minnowette What do you think?

It's a difficult call. The copper is about 23 times higher than in aquarium ferts, and that might call for too much mixing in attempting to correct it to a lesser concentration.

I find that if you can't source a micro fert mix with the right chelated iron, it's perfectly fine to use it and add the right chelated iron as a separate stand alone fert. For example I use DTPA chelated iron and Flourish (where the iron is in the form of ferrous gluconate).

Lots of countries have various restrictions on the sale and supply of fertiliser products (e.g. potassium nitrate can't be shipped via ordinary post in Australia as it's classified as a dangerous/explosive substance), but it might be worth seeing whether you can order a bulk supply of Plantex CSM+B from the US. Or you can investigate what options are available to other planted tank aquarists in South-East and East Asia and see if it might be possible to order a shipment.

 

Minnowette You seem to know a lot about this topic so hopefully you don't mind another question...

When googling EDDHA Fe6 there seems to be different versions and the difference is the Ortho-Ortho Content, e.g.
EDDHA Fe6% O-O 4.8
EDDHA Fe6% O-O 3.6
EDDHA Fe6% O-O 1.8
etc.

All of them are listed as 100% water soluble

I have found a source of EDDHA Fe6% locally but there's no mention of O-O Content - is it important?

 

Ortho-Ortho Content

I wouldn't want to misrepresent as a chemist or botanist (definitely not!), just an interested hobbyist with perhaps far too much free time!

Short answer: Doesn't matter much for our purposes I think. I can't remember ever coming across an aquatic plant fertiliser that mentioned o-o, o-p or p-p.

Long answer: I have come across these terms before in terrestrial botany. From what I remember, o-o, o-p and p-p are isomer positional designations, i.e. they clarify where the hydroxyl groups (OH) are positioned in different EDDHA isomers.

The following diagram shows some examples of the differing position of hydroxyls in a few EDDHA isomers.




To an extent, it's important as the arrangement of hydroxyl groups determine the reactions that can take place. But as I mentioned, given that these are so rarely mentioned in aquatic plant fertilisers, it's likely the case that it isn't important for our purposes.

 

It is quite possible that only the ortho-ortho isomer allows iron binding between the six sites (two amines, two carboxyls and the two phenolic groups) since only o-o isomer has all 6 groups positioned close together.

 

It is quite possible that only the ortho-ortho isomer allows iron binding between the six sites (two amines, two carboxyls and the two phenolic groups) since only o-o isomer has all 6 groups positioned close together.

Based on what I see available for sale as water soluble you could very well be correct. So far I have only seen O-O versions.

Okay, I have now managed to find almost everything locally in small quantities, except for Molybdenum.

I found 3 different versions of chelated iron and plan for either EDDHA or DTPA.
EDTA E-FE13
EDDHA Fe6
DTPA D-Fe11

I also managed to find FeSO4.7H2O Iron (II) Sulfate but then I won't have the benefits of the chelates and hence I guess most of the iron won't be available to the plants with my PH at 8.2?

I found the following other micronutrients

MgSO4 Magnesium Sulfate
ZnSO4.H2O Zinc (II) Sulfate
CuSO4.5H2O Copper (III) Sulfate
MnSO4.H2O Manganese (II) Sulfate
H3BO3 Boric Acid

Can I mix these together with the chelated iron and if yes will they also benefit from the chelates or am I better off keeping the chelated iron separately?

In other words, what would you recommend that I do with the above availability of chemicals? Are there other chemical compositions besides the ones listed that would be better?

PS: As I am writing this I managed to find yet another local supplier with many more chemical compositions and also Na2MoO4.2H2O Sodium molybdate dihydrate

 

I also managed to find FeSO4.7H2O Iron (II) Sulfate but then I won't have the benefits of the chelates and hence I guess most of the iron won't be available to the plants with my at 8.2?

Other nutrients can indeed benefit from the chelate. Whether you mix it together or separately won't - in my line of thinking - particularly make a difference as it all ends up as a single solution when you dose it in the tank. Most people mix it in with the rest of their micros as a matter of a convenience and a way to benchmark their micro dosing (i.e. dose based according to iron concentration, and the other micros should be in sufficient concentration).

In other words, what would you recommend that I do with the above availability of chemicals? Are there other chemical compositions besides the ones listed that would be better?

PS: As I am writing this I managed to find yet another local supplier with many more chemical compositions and also Na2MoO4.2H2O Sodium molybdate dihydrate

Sodium molybdate works fine, so too does ammonium molybdate.

I think you've done a marvellous job in assembling all the compositional compounds! They all look appropriate to me. I think now it's just a matter of purchasing them and mixing together either in dry form or as a solution. Of course, a milligram scale will be very useful (almost necessary I would say).

I assume you're aware of this (but just in case you aren't), you'll need to convert Plantex CSM+B's percentage of a nutrient into a mass that takes into account the molar mass of the particular compound you're using.

So 1.4% Mg (pert Plantex CSM+B) in 100 grams of your fert mix would not mean 1.4 grams of MgSO4, but 5.53 grams.

 

Other nutrients can indeed benefit from the chelate. Whether you mix it together or separately won't - in my line of thinking - particularly make a difference as it all ends up as a single solution when you dose it in the tank. Most people mix it in with the rest of their micros as a matter of a convenience and a way to benchmark their micro dosing (i.e. dose based according to iron concentration, and the other micros should be in sufficient concentration).



Sodium molybdate works fine, so too does ammonium molybdate.

I think you've done a marvellous job in assembling all the compositional compounds! They all look appropriate to me. I think now it's just a matter of purchasing them and mixing together either in dry form or as a solution. Of course, a milligram scale will be very useful (almost necessary I would say).

I assume you're aware of this (but just in case you aren't), you'll need to convert Plantex CSM+B's percentage of a nutrient into a mass that takes into account the molar mass of the particular compound you're using.

So 1.4% Mg (pert Plantex CSM+B) in 100 grams of your fert mix would not mean 1.4 grams of MgSO4, but 5.53 grams.

I am aware that I need to convert but haven't got my head around how yet. I know the Molecular weight of MgSO4 is 120.366 g/mol but please do enlighten me on your calculation.

Okay, got myself into the calculations. When looking for a target ppm for Mg there's a huge difference between Rotala Butterfly's "EI low light / weekly" recommendation of 5 ppm and CSM+B's outcome of only 0.043 ppm (based on Fe target of 0.2). Any idea why there such a difference? FYI: Rotala Butterfly Fe recommendation is 0.1 for Fe.

I also noticed that is unlikely that I will actually get MgSO4 but rather MgSO4.7H2O despite all the suppliers only listing the former. So based on this I did a manual calculation:


Fortunately my calculation gives the same result as Rotala Butterfly. So based on this I need 507 grams of Epsom salt for every liter of water in my solution and I need to doze 150ml weekly to obtain 5 ppm in my 1500 liter tank.

That's a lot of Epsom salt I think? Why is the RB recommendation so high or have I misunderstood the Mg amount in CSM+B?

 

I am aware that I need to convert but haven't got my head around how yet. I know the Molecular weight of MgSO4 is 120.366 g/mol but please do enlighten me on your calculation.

Oops, my initial calculation was incorrect: I divided molar mass Mg by molar mass SO4. It should be: molar mass Mg divided by molar mass MgSO4 = 24.305 / 120.366 = 0.2019. So 20.19% of any given mass of MgSO4 will be in the form of Mg.

Mass of MgSo4 required to arrive at a 1.4% concentration of Mg in 100 grams of fert = 1.4 grams * (1 / 0.2019) = 6.93 grams.

The same formula can also be applied for magnesium sulfate heptahydrate.

That's a lot of Epsom salt I think? Why is the RB recommendation so high or have I misunderstood the Mg amount in CSM+B?

No, you're right. Generally most of these pre-mixed micro ferts have rather low calcium and magnesium based on the implicit understanding that your source water has sufficient Mg and Ca. In most cases, most people adjust their GH (i.e. Mg/Ca concentration) separately from the rest of their micro ferts using a standalone GH Booster (typically CaSo4 and MgSO4.7H2O) or they'll adjust their Mg alone with MgSO4.7H2O.

The little MgSo4 that is added in these ferts, I think, is done so as a matter of convention.

This is why your CSM+B has a low Mg concentration while RB has listed a higher ppm target listed: the former assumes your source water has enough, the latter doesn't.

I need 507 grams of for every liter of water in my solution and I need to doze 150ml weekly to obtain 5 ppm in my 1500 liter tank.

In addition, you can use a slightly more concentrated solution if dosing MgSO4.H2O separately from your other micro ferts. The solubility of MgSO4.H2O at 20 degrees Celsius is 113 grams per 100 ml water, so you can use a 75 ml dosing amount (which would 90% of the compound's saturation) and a total mass of 1,014.13 grams MgSO4.7H2O in 1,000 ml water.

To help aid solubility in concentrated solutions, I generally heat the RO/distilled water for a little bit in the microwave.

In addition, I suspect another reason why Mg and Ca is added as a separate supplement is that the water solvent would rapidly reach the saturation point because of their larger dosing requirements (e.g. 5 ppm Mg vs 0.2 ppm Fe): it's probably easier to just dose MgSO4.7H2O separately. Further to that, CaSO4 has very low solubility in water (0.24 g per 100 ml water at 20C) which is likely why it's rarely added to these pre-mixed ferts.

 

This is not intended as criticism of or argument against anything written above.

I probably learned enough science and math 50-60 years ago to follow Minnowette into this pool but I druther swim in shallower water. My strategy is to take dosing advice specific to a particular compound from a trusted supplier or advisor. So references to molar mass were brand new to me and when I first saw them in a bullet point list that began with Easy Dosing Calculations, I assumed the post was meant to be funny.

Minnowette is certainly one of the sources of advice I would turn to. The folks you bought the nutrient from will often recommend a specific dosing rate for the product they sell. Another good information source is a guy named Nate Storey. He made some excellent YouTube videos a few years ago and although he has since moved on, the vids are still available through YouTube's BrightAgrotech Channel. There are 16 in the subgroup called Aquaponic Nutrient Management that I've found particularly useful and

,

, and

are particularly relevant to the discussion in this thread.

Once again, I'm not contradicting anything or anyone. I'm simply offering a different perspective in case somebody reading this needs a leg up getting to a target parts per million, or milligrams per liter.

 

skilletlicker I appreciate all comments on this topic. The more discussion the better in my view.

One main reason for me going down this route is the lack of local availability of pre-mixed dry ferts. Even if I was prepared to pay for Nilocg dry ferts they can be shipped out to me in Thailand. Second reason is the amount needed with weekly WC's in my 1500 Liter (375G) aquarium plus sump. I have bought some pre-mixed solutions locally but it's just too expensive in the long run and this company refuses to sell me dry compound of their mixes.....so there's no sellers to look to for advice, hence looking at CSM+B and others to get some ideas for mix.

I can fairly easily get the base chemicals from either chemical, hydroponics or plant fertilizer companies, all in 500g - 1 kg packs at really low prices, i.e. 1 kg KNO3 for USD 1.5 and most of the micros from USD 5 - 10 for 500g which in most cases will last me many months if not years.

I am almost done doing my calculations and doze decisions and I will post them here shortly. Would be very happy to get your input on this also.

My brown glass bottles have arrived. 3 X 2500 ml and 2 X 1000 ml. That was the rest stock of this particular supplier so now I need to see how I best get them to use.

Most likely 3 big macro bottles, although I will probably not doze Nitrogen until I see my Nitrates drop low. Then maybe two micro, with Iron DTPA chelate in one and the rest in the other....

 

Very exciting! On account of the bottle sizes, it's worth having a think - if you haven't already - about different ways of preserving the mixtures (especially the micro mix and iron) to avoid mould growth.

Refrigeration is often suggested, but I skirt the idea as I would hate to confuse a bottle of iron chelate for one of milk if ever I wake up thirsty at night.

I have read of others using 10-20 ml Excel or hydrochloric acid to 500 ml of their ferts as a preservative, and it seems to be a fairly common practice.

 

So is point is to mix solutions of dry chemicals for long-term storage and use those solutions to make additives as needed for your planted fish tank? I'm just guessing that the main advantage of this method is making weighing chemicals easier?

My storage is mostly repurposed plastic apple juice and milk containers, but I'm only mixing enough for one water change with enough extra leftover for top-offs. Storing it for a week or so at room temperature without light protection. My dry ingredients currently are just DTPA (chelated iron) and K2SO4 (potassium sulfate), counting on the fish, their food and waste, and the bacteria to supply the rest.

Am I missing something and do you think I should be using a preservative or refrigeration?

By the way, I have a bottle of worm composting juice in the fridge. Sure hope I don't mistake it something.

 

skilletlicker Yes the intention is to mix for several weeks and hence the preservative chemicals becomes more or less a necessity for the micro nutrients. Main reasons for my doing larger liquid quantities:

• I much prefer to measure out e.g. 50 ml every week of a mix already containing all / most micro nutrients compared to mixing it weekly or dry-dozing small amounts of dry chemicals.
• When preparing the mix I prefer to do it for several weeks use in one go and not doing it every 2 - 3 weeks. It is the same approach I take to my homemade pork heart mix, doing app. 2 kg of finished mix lasting me 2 - 3 months.
• It will also speed up my WC's not having to mix things on the go (and potentially get it wrong in a rush)

Plus overall purpose is to maybe move to 2 weekly WC's with a very small incremental fertilizer cost.

If you continue to only keep storing mixes for a week or so you should be good as is as long as it is in a dark place.

PS: In my case there's two boys constantly checking the fridge for anything worth eating or drinking, so I would not want anything in there in a apple juice container unless it is 100% apple juice ;-)

 

skilletlicker
PS: In my case there's two boys constantly checking the fridge for anything worth eating or drinking, so I would not want anything in there in a apple juice container unless it is 100% apple juice ;-)

My premixed fish tank water does look exactly like apple juice. Didn't think of that.

My brown glass bottles have arrived. 3 X 2500 ml and 2 X 1000 ml. That was the rest stock of this particular supplier so now I need to see how I best get them to use.

Didn't know if they drink much beer in your neck of the woods but Google shows some home brewing supply shops in Bangkok. That was the original purpose of these half-gallon 1.89 liter bottles.

 

Okay, I have come to some kind of conclusion of my mixing. I am more or less following the recommendation from Rotala Butterfly | Planted Aquarium Nutrient Dosing Calculator for "EI Low light / Weekly" and CSM+B or other places when there's not.

I have attached my calculations (in pdf since MS Excel is not accepted) and I think I will do as follows:

Macro: Mix 2500ml and doze 150ml per week / WC.
Micro: Mix 1000ml and doze 50 ml per week / WC.

I think this will keep me inside water solubility for all the chemicals and make dozing consistent, instead of e.g. dozing 150 ml Potassium and 100 ml Phosphate.

So broken down on bottle sizes:
Macros - doze 150 ml
2500 ml Potassium mix
2500 ml Phosphate mix
2500 ml Nitrogen mix (Will not be done initially due to high Nitrates)
Micros - doze 50 ml
2500 ml Magnesium mix
1000 ml Zinc, Copper, Manganese, Boron, Molybdenum, DTPA Fe 7% mix

Only problem left is my struggles finding accurate chemical data on the DTPA Fe 7% available to me and when I use "generic" DTPA Fe 7% molecular weights I am unable to replicate the Rotalabutterfly numbers. When they get 42.86 grams I only get 25.31 grams....and this annoys the heck out of me!!! Almost tempted to go back to iron sulfate although Fe availability is likely to be poor due to the high PH in the tank.

PS: I am happy to share my Excel file with anyone interested in the detailed calculations, just let me know.

My premixed fish tank water does look exactly like apple juice. Didn't think of that.

Didn't know if they drink much beer in your neck of the woods but Google shows some home brewing supply shops in Bangkok. That was the original purpose of these half-gallon 1.89 liter bottles.
View attachment 482862

Thai's do like their beer a lot (as do most of us foreigners here it seems...) but we haven't really embraced the micro brewery idea to any great extent so far...so I didn't think of that option. Just checked one supplier and saw a nice big CO2 tank. Could come in handy later even if I don't get any bottles....Thanks!

 

Here is the latest micro mix on Barr Report that works much better than CSM+B. DTPA would suit your needs. CSM uses EDTA. Maybe also 0.5 Mg while keeping GH around 8 ppm Mg and 28 ppm Ca.

Fe - .15 ppm
Mn - .05 ppm
B - .045 ppm
Zn - .05 ppm
Mo - .0015 ppm
Cu - .002 ppm
NI - .0005 ppm

Here is the link :

Here is another link :
The Custom Micro Mix Thread - Page 68 - The Planted Tank Forum

Burr740 is the guru on this subject, start by reading his posts.


Quoting Burr740 on mold prevention:

"Easiest thing would be try more vinegar. 5 ml per 500 ml is really a bare minimum, 10-20 is fine. Some people use even more but I haven't personally.

Potassium sorbate would be a stronger mold preventative, .25 gram per 500 ml (plenty) But then you also need an acid to set the PH, I like ascorbic at .5 gram per 500 ml.

Ascorbic by itself will prevent mold in mine, as does vinegar. But if you have a stubborn problem potassium sorbate is better.

Macros are actually more prone to mold for me, that's what I use it for."


FYI: The vinegar should be distilled vinegar.

 

Apologies for not checking into the thread earlier!

Am I missing something and do you think I should be using a preservative or refrigeration?

I don't bother with refrigeration or preservation as, like you, I only mix enough to last a few weeks (2-4): there never seems to be any particularly noticeable mould growth over that period of time. But I do keep it in an amber bottle and stored in a closed cabinet, out of the light.

Only problem left is my struggles finding accurate chemical data on the DTPA Fe 7% available to me and when I use "generic" DTPA Fe 7% molecular weights I am unable to replicate the Rotalabutterfly numbers. When they get 42.86 grams I only get 25.31 grams....and this annoys the heck out of me!!!

This is the calculation for chelated nutrients that rotalabutterfly (using their EI low light/weekly parameters):

1500 litres x 0.1 ppm Fe = 150 mg Fe

150 mg Fe x (1 / 7% chelate) = 2,142.86 mg Fe

2,142.86 mg Fe x (1000 ml / 50 ml) = 42,857.2 Fe.

The difference lies in the interpretation of '7%' in the chelate's description: it's a w/w fraction, that is, every 100 g of the compound will contain 7 g (7%) Fe, and 93 g (93%) as the DTPA chelate. It is otherwise not related to molar mass.

 

Ordering my micro stuff today, including a scale that will do 0.01 g increments for a maximum of 500 g. Next is ordering macro stuff plus DTPA iron from another vendor. Finally ordering Potassium Sorbate from a third vendor.

I have been reading up on Potassium Sorbate to find out how much to add. Haven't found much information, but one post on planted tank mentioned 0.5g for a 1000 ml solution. I guess the 1 kg I am getting will last me a lifetime.....good thing it is less than USD 5 plus shipping!

I have also been looking around for distilled water but unless I order it by tanker truck load it seems difficult to get. I am not going into distilling it myself either, so I think I will have to settle for my filtered drinking water. My TDS meter says 122 for the drinking water so not too bad I think.

Potassium sorbate would be a stronger mold preventative, .25 gram per 500 ml (plenty) But then you also need an acid to set the PH, I like ascorbic at .5 gram per 500 ml.

My planted tank reference seems to be in line with this. Just didn't consider the Ascorbic Acid but I can get this too from the same vendor. Might kill two birds with one stone since I have been looking to add vitamin C to my pork heart mix for the discus.

 

Ordering my micro stuff today, including a scale that will do 0.01 g increments for a maximum of 500 g. Next is ordering macro stuff plus DTPA iron from another vendor. Finally ordering Potassium Sorbate from a third vendor.

I have been reading up on Potassium Sorbate to find out how much to add. Haven't found much information, but one post on planted tank mentioned 0.5g for a 1000 ml solution. I guess the 1 kg I am getting will last me a lifetime.....good thing it is less than USD 5 plus shipping!

I have also been looking around for distilled water but unless I order it by tanker truck load it seems difficult to get. I am not going into distilling it myself either, so I think I will have to settle for my filtered drinking water. My TDS meter says 122 for the drinking water so not too bad I think.

You could find distilled water in supermarkets and in pharmacies. They sell them for the Ironing Machines and pharmacies have them for medicinal dilution.

 

Here is the latest micro mix on Barr Report that works much better than CSM+B. DTPA would suit your needs. CSM uses EDTA. Maybe also 0.5 Mg while keeping GH around 8 ppm Mg and 28 ppm Ca.

Fe - .15 ppm
Mn - .05 ppm
B - .045 ppm
Zn - .05 ppm
Mo - .0015 ppm
Cu - .002 ppm
NI - .0005 ppm

Here is the link :

Here is another link :
The Custom Micro Mix Thread - Page 68 - The Planted Tank Forum

Burr740 is the guru on this subject, start by reading his posts.


Quoting Burr740 on mold prevention:

"Easiest thing would be try more vinegar. 5 ml per 500 ml is really a bare minimum, 10-20 is fine. Some people use even more but I haven't personally.

Potassium sorbate would be a stronger mold preventative, .25 gram per 500 ml (plenty) But then you also need an acid to set the PH, I like ascorbic at .5 gram per 500 ml.

Ascorbic by itself will prevent mold in mine, as does vinegar. But if you have a stubborn problem potassium sorbate is better.

Macros are actually more prone to mold for me, that's what I use it for."


FYI: The vinegar should be distilled vinegar.

How do you test the ppm for those elements? Is it just the amount that’s in a measuring cup?

 

How do you test the ppm for those elements? Is it just the amount that’s in a measuring cup?

They come in a pure solid salt form. One prepares a DIY solution by measuring them in terms of grams. Most hobbyist use the help of RotalaButterfly. For example: The ppm's would be per pump ( 1ml ) per 10 litres.

 

The difference lies in the interpretation of '7%' in the chelate's description: it's a w/w fraction, that is, every 100 g of the compound will contain 7 g (7%) Fe, and 93 g (93%) as the DTPA chelate. It is otherwise not related to molar mass.

Thanks, I was pulling my hair over this one....and trust me there's very little of it left to start with

You could find in supermarkets and in pharmacies. They sell them for the Ironing Machines and pharmacies have them for medicinal dilution.

Yes, that would also apply to my native country in Europe but seems not to apply to Thailand. All the have is saline solutions for cleaning the nose of (mostly) children.....

I think I am going to take my chances with the filtered drinking water. Although I don't know what causes the TDS reading of 120 it seems low compared to most other readings I have seen listed out there. Maybe my biggest problem is going to be the PH of the drinking water. Coming out of the tap at around 7 - 7.2 maybe it will make most of the micros unattainable to the plants before they even left the bottle?

 

I think I am going to take my chances with the filtered drinking water. Although I don't know what causes the reading of 120 it seems low compared to most other readings I have seen listed out there. Maybe my biggest problem is going to be the PH of the drinking water. Coming out of the tap at around 7 - 7.2 maybe it will make most of the micros unattainable to the plants before they even left the bottle?

(1) The main area of concern when using tap water is the precipitation reactions between phosphate and other nutrients (particularly iron, aluminium and calcium).

(1) It's highly unlikely that your tap water is rich in iron or aluminium, which react with phosphate - in more acidic conditions - to form the more insoluble precipitates of phosphate salts. In any case, it's not strictly true that nutrients become totally unavailable if they oxidise or precipitate out of the water column: plant roots are capable of secreting compounds ("exudates") that increases the bioavailability of nutrients in the rhizosphere through various biological and chemical means.

(2) Much of the TDS in tap water is due to calcium carbonate, and to a lesser extent, magnesium carbonate. The reactivity between phosphate and calcium is increased in more alkaline conditions, precipitating into various calcium phosphates. However, these compounds have a higher degree of solubility in water, and if your tank has a more neutral/acidic pH, the precipitation will reverse.

(3) Given that we regularly dose ferts (daily/weekly) in planted tanks, this assists in off-setting any nutrient that is sequestered into a less bioavailable form over time. I find - from my own experience - that attempts to avoid precipitation (either by dry dosing or using distilled water) delivers, perhaps, marginal benefits at best.

 

Thanks Minnowette I think that tips the balance in favour of tap water, at least for batch one.

All dry ferts have now been ordered from the 3 different vendors. Everything should be here in maximum 5 days from now. Exciting times ahead....

Okay, finally got my act together and ordered an API GH & KH Test kit and I was in for a surprise....

Tap & tank water identical:
KH: 5
GH: 1

The GH never even got to change colour and basically started out in green....

So the assumption that my water (like for many others...) has enough magnesium was totally wrong and it looks like I better get on with a 5 ppp Epsom salt dosing right away. However GH is also build up of Calcium and I didn't plan to dose that but looks like I better do so, but what and how much?

Rotalabuttefly suggests 15 ppm

Then comes the chemical selection:

Calcium Nitrate
Calcium chloride
Calcium phosphate

Didn't initially wanted to add Nitrogen to my tank due to high Nitrates already but the other options are either dangerous (Chloride) or has very low solubility?

Minnowette I am afraid I need some wisdom from you once more....

PS: On a positive note, the lack of Calcium in my tap water should make it quite safe to use for mixing the ferts....

 

I don't think ive ever seen gh lower than kh, especially by that much.

 

I don't think ive ever seen lower than , especially by that much

Surprised me as well, but a brand new test kit with 9 months validity left on it so I tend to trust it for now. I have also been struggling with many of my plants and low GH would help explain that.

Google found me several similar cases.....here's two examples:

Help! low gh high kh and ph
Low Gh, High Ph, High Kh And Snails

 

GH and KH are independent of one another.
The GH test measures Ca and Mg, which are positively charged.
The KH test measures carbonates and bicarbonates, which are negatively charged.

Use calcium sulfate. Like epsom salt (magnesium sulfate), it doesn't mess around with nitrate and phosphate levels. I get a general GH booster from Nilocg that contains calcium sulfate, magnesium sulfate, and potassium sulfate. Seachem equilibrium also contains these things

 

Dear fa4960 ,

Use MgSO4 and CaSO4 to reach 8 mg/l Mg and 28 mg/l Ca.

Happy Fish Keeping

 

Use MgSO4 and CaSO4 to reach 8 mg/l Mg and 28 mg/l Ca.

There no way to reach 28 ppm Calcium with CaSO4. Solubility is 0.2g / 100 ml. Calcium sulfate is unfortunately one of the few sulfates with poor solubility.

 

There no way to reach 28 ppm Calcium with CaSO4. Solubility is 0.2g / 100 ml. Calcium sulfate is unfortunately one of the few sulfates with poor solubility.

If we convert 0.2 g/100mL to ppm don't we get 2000 ppm?

 

To reach 28 ppm Ca in my 1500 Liters of water I would need 180.43g of CaSo4.2H2O according to rotalabutterfly.com. Solubility is 2 gallon per liter so I would need to add 90 liters of pre-mixed fertiliser.

I could of course dry dose it, which seems to be the only option. I could dump it in the return chamber of the sump and let it dissolve there before being circulated.

Final problem, it doesn't seem to widely available in my area despite Thailand being a major producer, i.e. I think it is not widely used here, other than small amount for home breweries...

 

To reach 28 ppm Ca in my 1500 Liters of water I would need 180.43g of CaSo4.2H2O according to rotalabutterfly.com. Solubility is 2 gallon per liter so I would need to add 90 liters of pre-mixed fertiliser.

I could of course dry dose it, which seems to be the only option. I could dump it in the return chamber of the sump and let it dissolve there before being circulated.

Final problem, it doesn't seem to widely available in my area despite Thailand being a major producer, i.e. I think it is not widely used here, other than small amount for home breweries...

Oh yes, we did mean for you to use it dry. GH boosters come in block/powder form. As for availability, I'm not sure how to solve that one

 

There no way to reach 28 ppm Calcium with CaSO4. Solubility is 0.2g / 100 ml. Calcium sulfate is unfortunately one of the few sulfates with poor solubility.

Calcium and Magnesium are dosed in their dry form with each water change.

 

Did some more investigation on local availability of Calcium Sulfate and it turns out that it is used here also, and it is dirt cheap too. It is something like USD 5 - 7 for a 25 kg bag. Since I need app 100 g / 0.1 kg per dose I get 250 doses for the money. So I am off to the garden plants shops in the next week or so to chase down some Calcium Sulfate / Gypsum powder....

 

So it turned out that Calcium Sulfate / Gypsum powder is not very popular in Bangkok.....however managed to locate a company out in the sticks somewhere who mass produce this for the farmers. They have now finally agreed to send me 50 kg on the 20th December at the very reasonable cost of USD 25 including shipping. As I need 97g per doze I am good for 515 dozes at USD 0.05 each

In the meantime I picked up 25 KG of Epsom salt plus some more macro fertilisers. Finally also 500 g of Nickel (III) Sulfate or NiSO4.6H2O to complete my micro mix. Also switching from 7% iron DTPA chelate to 11% iron DTPA chelate since the price is the same while I use about 40% less to obtain the same ppm result.

Until I have used the last 7% iron chelate this is how I mix my solutions, also listing the correct dozing amount for my 1500 Liters of water (Tank + sump)