Blackwater 5 gallon journal!

HI everyone! I just set up a blackwater 5 gallon yesterday and thought it would be good for me to start a journal about it. First, here's the tank;




Here are the current specs;
PH: Just over 5 (I'm using a hydroponics PH test). My target range is between 4 and 5.5.
KH: Well below 1 degree (probably close to zero). My target range is as close to zero as possible.
TDS: 11 ppm (or about 18 microsiemens conductivity). My target range is no higher than 50 ppm TDS (80 microsiemens conductivity) and ideally no higher than 25 ppm (40 microsiemens)
Filter: Currently an air powered bottle filter with sand at the bottom, crushed hydroponics clay media in the middle, and polyfil at the entrance of the bottle.
Substrate: Bottom layer of peat moss, middle layer of leaves, top layer of sand.

Here are some specs for the final tank;
Filter/circulation: the biological filter will be a water pump with a sponge filter over the intake. The bottle filter will be used for mechanical filtration and will be on a timer that turns it off between 5 am and 1:30 pm; the off period will allow CO2 to accumulate from the decaying organic matter and make conditions easier for the plants to deal with.
Temperature: Most likely mid-high 70's fahrenheit.
Fertilizer: None in the water column, but I'm experimenting with how my lily tabs affect water parameters in an experimental setup (basically a bottle with sand, 1 quart distilled water, and 1/3rd of a lily tab) when buried in the sand. If my experiments find that the lily tabs have only a minor influence on TDS and other parameters, I will add 1/2 of a lily tabs to the substrate under the plants (in multiple pieces, of course) once a month right before a water change.
Light: A 5000 K, 16 watt, 1600 lumen LED bulb, on from 7 am to 1 pm.
Plants: Not 100% sure what I will use in this tank, but Mayaca fluvitalis (which hails from blackwater rivers in the wild, such as the Rio Negro) will most likely be included.
Fish: Most likely either wild bettas or licorice gouramies.
Maintenance schedule: The tank will be fed 5 days a week with 1/8th teaspoon of food (perhaps split into two portions) and will receive 40% WC's once a week. The water will be produced by (A) when available, collecting rainwater and filtering it with coconut shell carbon, or (B) by filtering my tap water through coconut shell carbon and DI resin.
Setup schedule: I will let the tank run as is for about a month, and then will add a light, plants, the water pump, and the aforementioned timer for the air pump. I will wait another month or two before adding fish; the fish will be quarantined in a 2.5 gallon jar for a few weeks to a month to check for illness, get them adjusted to the tank's parameters as needed, make sure they are eating, try to convert them to dead food if possible (will feed them baby brine shrimp and microworms regardless), and try to get them used to my presence before adding them to the tank.

This is a lot, I know...thanks for reading

 

Nice!! I'm working on a similar set-up, except without peat and in a somewhat larger tank (33G). Curious to hear how it goes, do post periodic updates!

Wondering though, you do realise biological filtration doesn't funtion below PH 6? Or did I read it wrong that you wanted to include that?

 

Is sand safe for bettas?

 

Is sand safe for bettas?

? why wouldn't it be

 

Nice!! I'm working on a similar set-up, except without peat and in a somewhat larger tank (33G). Curious to hear how it goes, do post periodic updates!

Wondering though, you do realise biological filtration doesn't funtion below PH 6? Or did I read it wrong that you wanted to include that?

The common nitrifying bacteria use carbonates in the process of processing ammonia/ammonium and thus do not establish readily in such soft tanks; however, at PH values below 6, almost all of the 'ammonia' in the water is actually ammonium, NH4, which is far less toxic and could be dealt with by the plants and/or with water changes. In addition, there are also nitrifying archaeaobacteria (which, in spite of their name, are a completely different domain of life from bacteria) that can develop well even at low PH levels. I quickly did some additional research after seeing your post and found this from the Microbiology society;

" With the discovery of archaeal ammonia oxidisers and media enabling their cultivation, the obligately acidophilic archaeon Nitrosotalea devanaterra was isolated from a pH 4.5 soil at the University of Aberdeen in 2011, and provided the most parsimonious explanation of why nitrification can occur in acidic soils. The subsequent cultivation of other Nitrosotalea strains, together with surveys of acidic soils globally, indicates that Nitrosotalea are major players contributing to this process. Despite growing only in acidic conditions, physiological and genomic evidence indicates that these organisms oxidise ammonia and not ammonium, and may grow by transporting ammonium intracellularly before subsequent conversion to ammonia and oxidation."

 

Is sand safe for bettas?

I have no clue for domesticated bettas, but I can't think of any reason that an inert sand would pose a problem for wild bettas.

 

I thought I read somewhere that they mistake it for food sometimes and can kill them if they eat it.

 

I thought I read somewhere that they mistake it for food sometimes and can kill them if they eat it.

Wild bettas are often hesitant to take dead food, so I'd be surprised if that was an issue for them...I will do more research now that you mentioned it, though.

 

The common nitrifying bacteria use carbonates in the process of processing ammonia/ammonium and thus do not establish readily in such soft tanks; however, at PH values below 6, almost all of the 'ammonia' in the water is actually ammonium, NH4, which is far less toxic and could be dealt with by the plants and/or with water changes. In addition, there are also nitrifying archaeaobacteria (which, in spite of their name, are a completely different domain of life from bacteria) that can develop well even at low PH levels. I quickly did some additional research after seeing your post and found this from the Microbiology society;

" With the discovery of archaeal ammonia oxidisers and media enabling their cultivation, the obligately acidophilic archaeon Nitrosotalea devanaterra was isolated from a pH 4.5 soil at the University of Aberdeen in 2011, and provided the most parsimonious explanation of why nitrification can occur in acidic soils. The subsequent cultivation of other Nitrosotalea strains, together with surveys of acidic soils globally, indicates that Nitrosotalea are major players contributing to this process. Despite growing only in acidic conditions, physiological and genomic evidence indicates that these organisms oxidise ammonia and not ammonium, and may grow by transporting ammonium intracellularly before subsequent conversion to ammonia and oxidation."

Yes, I am aware of the ammonia not being toxic, I thought the whole point of an acid blackwater set-up is to have one where you just do small weekly changes (~10%) to prevent OTS and everything else can just be left uncycled. Or that is how people have done it apparently.

But that part about the archaeaobacteria is totally new to me! Thank you so much for that nugget, that calls for some more reading on my part, I had no idea that was a thing. Is that supposed to just grow in your acid tank without external interference, like the normal cycle establishes itself as long as you have a food source present?

I thought I read somewhere that they mistake it for food sometimes and can kill them if they eat it.

Even if domesticated, bettas are not idiots fortunately I doubt they would eat sand. Many fish actually eat sand, filter out food morsels and spit them back out. I've yet to hear about a betta dying because it swallowed mouthfuls of sand.
I have heard that they can try to swallow larger objects (like pebbles and twigs) and get it stuck.. but I wonder about those stories. Pretty sure 99.9% of folks keep their betta with pebbles/gravel without issue.

 

I have no clue whether the desired archaeobacteria naturally find their way into aquariums...however, my past licorice gourami tanks (with PH in the 4's) did occasionally develop non zero nitrate levels, implying that they did cycle. What I do know is that archaeobacterial nitrifiers are widespread - they outnumber their bacterial counterparts in the open ocean, for example. Interestingly, denitrifying bacteria (the anaerobic bacteria that turn nitrate back to nitrogen gas) are common in Asian peat swamps, implying something is oxidizing ammonia in those habitats.

 

Even if domesticated, bettas are not idiots fortunately I doubt they would eat sand. Many fish actually eat sand, filter out food morsels and spit them back out. I've yet to hear about a betta dying because it swallowed mouthfuls of sand.
I have heard that they can try to swallow larger objects (like pebbles and twigs) and get it stuck.. but I wonder about those stories. Pretty sure 99.9% of folks keep their betta with pebbles/gravel without issue.

LOL. I’ve actually seen my betta try to eat my sandy substrate so he may be on to something. But I did see my betta spit it out immediately, so I don’t think it is too much of a problem.

 

I have no clue whether the desired archaeobacteria naturally find their way into aquariums...however, my past licorice gourami tanks (with PH in the 4's) did occasionally develop non zero nitrate levels, implying that they did cycle. What I do know is that archaeobacterial nitrifiers are widespread - they outnumber their bacterial counterparts in the open ocean, for example. Interestingly, denitrifying bacteria (the anaerobic bacteria that turn nitrate back to nitrogen gas) are common in Asian peat swamps, implying something is oxidizing ammonia in those habitats.

Very interesting info! I really need to spend some time reading up on this.
I'm tempting to go out and check the many bodies of water near my house filled with rainwater and organic debris. I've tested the PH before and it is below 6, curious now if I can get nitrate readings on any of those. May consider seeding if I do.

 

LOL. I’ve actually seen my betta try to eat my sandy substrate so he may be on to something. But I did see my betta spit it out immediately, so I don’t think it is too much of a problem.

How amusing! So many pets have the strangest tastes Were the bettas pecking at some unseen copepod or other tiny critter that happened to be on the sand?

 

How amusing! So many pets have the strangest tastes Were the bettas pecking at some unseen copepod or other tiny critter that happened to be on the sand?

I doubt it. My tank doesn’t have enough biofilm or other natural elements for most microorganisms to exist on.

 

HI everyone! Just a little update...the tank is showing a nice tannin color now, partially due to the leaves and partially due to a decaffeinated tea bag I added for tannins, and its TDS level is now 14 PPM (well within the desired range). More importantly, though, I gave some thought to my plans for this setup...natural blackwater habitats don't have people inserting root tabs into them and thus tend to be somewhat short on many nutrients, especially minerals. As such...it seems unwise for me to try to fertilize this tank (excepting possibly light NPK fertilizing at the substrate level), as I am concerned that any minerals not taken up by the plants will accumulate in the substrate and eventually start impacting the water quality. Thus, I will run the air powered bottle filter constantly, perhaps run a refugium with a water pump (as a built in fry tank) and use plants I have had good experiences with in these tanks in the past, such as;
- Java moss
- Java fern (not the brackish-loving phillipine variant)
- Mayaca fluvitalis
- Golden creeping jenny
- and maybe others...

With all of that said...here's a picture of the tank from a few minutes ago. Enjoy!

 

Wow I’m excited to see how this tank progresses! I’m rescaping my 10 gallon to have more of a blackwater feel but nothing at this level!

 

Wow I’m excited to see how this tank progresses! I’m rescaping my 10 gallon to have more of a blackwater feel but nothing at this level!

Thanks! The setup has thus far been progressing perfectly...nothing to complain about. Let's hope that continues...I've had enough tanks where the setup went spectacularly wrong (trying to place peat moss as the ONLY substrate in a prior blackwater tank, for example...the blasted stuff floats for days if not capped!)

In other news, I was looking at my other 5 gallon (a dirted tank with hard water) and I discovered a 6 mm long fry in there! It is almost certainly an Aphanius mento fry that hitchhiked from the 10 gallon above it when I took some round pellia and java fern from that tank and put it in the 5 gallon...as it's probably not the only fry I will find, I promptly restarted my brine shrimp hatchery.

 

HI everyone! Another update...I had planned to make the soft water for my fish by passing my tap water through bottle filters filled with activated carbon and DI resin. Well...I got the carbon in the mail today and tried that, and it backfired horrendously My tap water - which started at 38 ppm TDS after I added dechlorinator - jumped to a horrendous 200+ ppm after putting it through both filters. I'm not sure what went awry here...I'm probably just going to use distilled or store bought RO water as the base water for this tank for now, supplemented with rainwater if it is available. I guess I should not have claimed this setup was going off without a hitch...

 

I guess I should not have claimed this setup was going off without a hitch...

Rule #1 of the aquatic hobby: never ever EVER say things are going well. Or swimmingly. Or will finally be fine from here on out.

The curse of the jinx is undeniably powerful...


(Could it just be a poor quality filter? Sounds like something is leaking and mingling with the water)

 

I love this, so informative too! I can’t wait to see what happens next.

 

The end product is going to be epic. Can't wait !

 

Thanks! Glad to see you guys like my work

I think I figured out what went wrong with the filter. You see, it consisted of two parts - a bottle filled with activated carbon and a bottle filled with DI resin. I was planning to put the water through the carbon filter, pour it into the DI resin, then pour that into a collection container. The problem is that I had trouble getting the DI resin in the bottle and thus crushed much of it...releasing the resin's ions into the water. I will likely need new DI resin if I am to try this again, though the carbon is most likely salvageable.

 

Thanks! Glad to see you guys like my work

I think I figured out what went wrong with the filter. You see, it consisted of two parts - a bottle filled with activated carbon and a bottle filled with DI resin. I was planning to put the water through the carbon filter, pour it into the DI resin, then pour that into a collection container. The problem is that I had trouble getting the DI resin in the bottle and thus crushed much of it...releasing the resin's ions into the water. I will likely need new DI resin if I am to try this again.

Not to be stereotypical, but if at first you don't succeed, try try again .

 

HI everyone! Just a small update I got a round 17 gallon storage tote today. It will be used for collecting rainwater for my tank...conveniently it is raining quite hard today, so I put it outside as soon as I got home. My apartment has no gutter, so I simply put it under the edge of the roof where the water drips off the roof.

 

Hello again everyone! Rather soon for an update, but I think this deserves a separate post. I want to have the low target PH for this tank maintained by decaying organic matter, but since there's a chance I will not be successful in accomplishing that, I have started testing chemical alternatives. I performed three tests with API ph down a few minutes ago - one with 2 drops per 500 ml of distilled water (as a benchmark), one for 2 drops per gallon, and one for 1 drop per gallon. The result? The stuff is FAR too strong in distilled water...even with one drop per gallon (half of API's recommended dose and which added only 6 PPM TDS to the water) the PH dropped to at least 4 (!) and perhaps lower, as my hydroponics PH kit does not measure PH values below 4. The search for the appropriate acid continues unabated...

On another note...my rainwater bin is working It is now filled with about 4 inches of water from today's storm. I don't know how many gallons that is (it's likely several), but at least it is definitely working as planned.

EDIT: I did more experimenting and did not want to make a third new post the same day Anyhow, I - out of curiosity - decided to test how Thrive C liquid fertilizer would affect water parameters. The tests revealed two surprises; (1), Thrive C is acidic! A milliliter of Thrive C in 500 ml of distilled water sent the PH down to 4 or lower! and (2), a milliliter of Thrive C added 190 ppm TDS to 500 ml of distilled water...that sounds like a lot, but when scaled up to its intended use in a 5 gallon (with dozens of times more water volume to dilute the Thrive) that's only 6-7 ppm TDS added to the water if I dosed it all at once (and I was going to dose a seventh of that each day). Perhaps this tank is compatible with fertilizer after all...

 

HI everyone! I collected quite a bit of rain last night...but, when I went to test it with my TDS meter, it came up as 15 ppm. A bit higher than I would like...I opted not to use the rain water because I do not know what composed that 15 ppm. I will test it again next time we get a decent rain storm, and if I get such high values again I may need to harvest rain directly from the sky - obviously not as productive a method than gathering part of what runs off a roof.

 

HI everyone! Tomorrow the tank will have been set up for a week I have plants coming in the mail this upcoming week...since I will be lightly fertilizing the tank now, I am being somewhat less cautious with what plants I will attempt in this tank. Here are the plants coming in the mail next week;

- Mayaca fluvitalis (grows in blackwater streams in the wild, so a reasonable choice...plus I have used it successfully in similar tanks before)
- Golden creeping jenny (again, have used this species before)
- Rotala rotundifolia 'H'ra' (never tried it before, but AquasabI states this plant and other rotundifolia variants can take a PH as low as 4 and virtually no hardness...worth a shot)

In addition, I will be acclimating some plants from my current tanks to this setup. These plants may include;
- Round pellia
- Java fern

Tomorrow I will perform my first 40% WC on this tank. The new water will have a VERY small (1 drop per gallon) amount of API ph down...I discovered that I must have messed up my experiment before, as when I accidentally added two drops to a gallon of distilled water, it 'only' pushed the PH to the high 4's. I will also be adding half of the tea produced by a decaffeinated tea bag in 250 ml of distilled water (basically 120 ml of tea) and - over the course of the week - 1 ml of thrive C.

 

HI everyone! Yesterday night I did my first water change on the blackwater tank. The old tank water had a PH of about 6 and about 20 ppm TDS; to replace it, I added two gallons of distilled water to which I had added half a cup (about 120 ml) of decaffeinated tea, two drops API PH down, and two leaves. The new water had a PH in the high 4's and about 9 ppm TDS; after the water change the tank had a PH in the mid 5's and about 14 ppm TDS.

Now that all that technical stuff is discussed, here's some more exciting updates My plants are arriving tomorrow, so later today I will be setting up a quarantine jar to adjust them to the parameters of this blackwater tank over the course of a few days and to treat for hydras (which could be an issue in a tank that is going to regularly receive small live foods). I am going to experiment with increasing CO2 levels in this tank after the plants are added...as previously mentioned, I will do so by turning off all surface agitation one or two hours before the light comes on and only turning the air pump back on after the light turns off. I am hoping the bacteria, fungi, plants, and eventually fish in the tank produce enough CO2 to improve plant growth (I made an experimental tank based on this principle in the past with no surface agitation whatsoever, but while it did have elevated CO2 levels, it also became anoxic and eventually crashed from an ammonia spike...this experiment will be a compromise in an attempt to increase CO2 levels during the day without creating anoxic conditions at night). I will also start dosing Thrive C after the plants are in the tank.

Of course, a build thread is not complete without pictures...here is a picture of the tank as of a few minutes ago. Enjoy

 

HI again everyone! Minor update time. I went to two local stores with public reverse osmosis units - a Walmart and a Hannaford, respectively - to see if their water was usable for my black water tank. The Walmart water had 15 ppm TDS - significantly higher than I wanted (I don't think I am going to use that water in the tank without purifying it further). HOWEVER, the Hannaford unit produced water with 0 ppm TDS, in spite of the fact that the machine did not mention any deionizing components in the filter...suffice to say that (A) you can get water pure enough for a small blackwater tank from a grocery store without breaking the bank (each gallon was 50 cents...I believe it was glacier brand water?) and (B) make sure you test any RO water you get from a grocery store for contaminants before using it.

Anyhow, I am getting more DI resin in the mail this week, so hopefully I will be able to produce my own purified water at a cheaper price than either store.

 

My plants just arrived Here's a picture of the plants (plus the round pellia I added to this QT tank yesterday);


And here is the QT tank itself;


The QT tank is a 2.5 gallon jar heated to 78 degrees. It is lit by 800 lumens of 5000k LED daylight, produced by an incandescent replacement bulb. The light is on for 7 hours a day...all the above is similar to the light that will be put on the main tank. The plants consist of about a cup of round pellia (added yesterday from one of my main tanks), two Rotala H'ra bunches, one golden creeping jenny bunch, and three Mayaca fluvitalis bunches.

I will be treating the tank for hydras for the next two days, and then acclimating most of the plants to the blackwater tank over the next few days before planting them Sunday after the tank's water change. One of the Rotala bunches (sent as an extra by the vendor) will be going into my 5 gallon dirted tank instead and will be planted as soon as hydra treatment is done.

 

First off, thank you so much for sharing all of this! These are some incredibly informative posts and gave me so much information and ideas about my own set-up. A thousand thanks!

HI everyone! Tomorrow the tank will have been set up for a week I have plants coming in the mail this upcoming week...since I will be lightly fertilizing the tank now, I am being somewhat less cautious with what plants I will attempt in this tank. Here are the plants coming in the mail next week;

- Mayaca fluvitalis (grows in blackwater streams in the wild, so a reasonable choice...plus I have used it successfully in similar tanks before)
- Golden creeping jenny (again, have used this species before)
- Rotala rotundifolia 'H'ra' (never tried it before, but AquasabI states this plant and other rotundifolia variants can take a PH as low as 4 and virtually no hardness...worth a shot)

In addition, I will be acclimating some plants from my current tanks to this setup. These plants may include;
- Round pellia
- Java fern

Tomorrow I will perform my first 40% WC on this tank. The new water will have a VERY small (1 drop per gallon) amount of API ph down...I discovered that I must have messed up my experiment before, as when I accidentally added two drops to a gallon of distilled water, it 'only' pushed the PH to the high 4's. I will also be adding half of the tea produced by a decaffeinated tea bag in 250 ml of distilled water (basically 120 ml of tea) and - over the course of the week - 1 ml of thrive C.

Could I ask what this plant acclimatisation process entails? Do you drop the PH/TDS slowly by doing water changes with increased portions of distilled water, or do you just put some peat in the filter and let it sort itself out?

Edit:
"I made an experimental tank based on this principle in the past with no surface agitation whatsoever, but while it did have elevated CO2 levels, it also became anoxic and eventually crashed from an ammonia spike "
Could you share some details on this? Did you pump CO2 in this tank or do you mean that in your experience, a zero-tech acid blackwater tank will crash when left alone?

 

Thanks! Good to know I am making a contribution to the hobby

I am going to lower the TDS, PH, etc with 1 gallon water changes with new blackwater Thursday through Saturday (after treating the plants for hydras). Normally I simply put plants straight into their new tank, but this blackwater tank is so much softer and more acidic than the vendor's water that I decided to be more careful lest the plants are severely shocked.

EDIT: Almost forgot! The jar's water has a TDS in the low 90's ppm. My tap has a TDS of 40 ppm after it is dechlorinated and I added less than 1/8 tsp of marine salt to 2 gallons of water to raise the TDS to that level. I did not test PH, but from prior experience it is probably around 6.

 

Could you share some details on this? Did you pump CO2 in this tank or do you mean that in your experience, a zero-tech acid blackwater tank will crash when left alone?

In the past, I made a 5 gallon dirted tank with no surface agitation whatsoever (not a blackwater tank, just an ordinary dirted tank). My goal was to see if organic decomposition and the respiration of the tank's inhabitants (bacteria, fungi, plants...I never added fish to this tank, but a few snails did colonize the tank) would produce enough CO2 to improve plant growth. It did...but the tank became anoxic, never cycled, and eventually crashed due to an ammonia spike. This time, I am going to apply what I learned from that mishap to attempt to increase CO2 levels during the photoperiod without gassing the tank out...basically the air pump will be off from an hour or two before the photoperiod starts and turn back on shortly after it ends, hopefully increasing CO2 levels during the day without gassing out the tank at night.

 

HI everyone! Today I started acclimating the plants to blackwater conditions. I did a 50% water change and replaced the old QT water with a gallon of distilled water, to which I had added 1/7th ml Thrive C, two drops API PH down, and a quarter of a cup of decaffeinated tea brewed in distilled water. Before adding this water to the tank, I checked the PH and TDS values of the new water and they came to about 4.5 and 12 ppm, respectively...ideal parameters for the blackwater tank. However, the tea added virtually no tannins to either the new water or the QT tank as a whole...I may need to rethink how I am going to add tannins to my blackwater tank, as the tea is just needlessly adding TDS at this point.

EDIT: Here's a useful tool for those trying to create soft, acidic tanks; pH Calculator | Calculate pH of a Solution | Sensorex

It's a calculator that allows you to calculate the exact PH of a solution of an acid and pure water. It would not be helpful if any significant amount of hardness lingers in the water, but it's a very useful comparative tool when trying to reduce the PH of distilled or RO water. For example...the calculator revealed that the PH of a solution of one gallon of distilled water with .012 grams of sulfuric acid in it (equivalent to two drops of API ph down, which is a 9.6% sulfuric acid solution) has a PH of about 4.49 - an answer that harmonized well with my earlier PH measurement on the aformentioned new water for the QT tank.

 

HI everyone! This is not a tank update, but still worth posting I found an article studying microbial communities in peat swamps in French Guinea; Differences in microbial community structure and nitrogen cycling in natural and drained tropical peatland soils

Particularly noteworthy to me is that, while the study did not find any ammonia oxidizing bacteria (EG Nitrosomonas, the bacteria that turn Ammonia into nitrite) they DID find functional amounts of Ammonia oxidizing Archaeal microbes. On quote; "We did not detect bacterial amoA in the studied tropical peatlands with the applied tools, while archaeal amoA genes were abundant at both study sites. These results are in agreement with Lu et al.40, who found a similar trend in acidic tea orchard and forest soils (pH 3.8–5.4). Because of the highly efficient anabolic pathways of AOA, which provide an ecological advantage compared to AOB in some environments41, AOA are known to be a dominant ammonia oxidiser in a wide range of soils"

The implication of all of this (at least in my eyes) is that unless the desired archaeal nitrifiers are not common outside of their native habitats, a highly acidic blackwater tank like mine should eventually cycle.

 

HI everyone! Tonight I will be putting the plants in the blackwater tank, but that's not what I am posting about now...instead, I am posting this; I made a successful DI resin filter! The filter is a 2 liter soda bottle I cut in half; to the bottle cap end I glued on (with silicone) some folded window screen to keep the resin in the bottle, and then added the resin and some polyfil over that. This time I handled the resin much more gently and apparently succeeded in not crushing much (if any) of it...42 ppm TDS dechlorinated tap water poured through the filter came out as 6 ppm water. Success

Now I have a few things I will be experimenting with to improve this filter;

Convenience - The filter's main flaw is that it is slower than expected - it takes about 20-25 minutes to process a single gallon of water, and since the filter is fairly small I need to regularly add more water for it to process during that interval. I am not sure whether this is due to a design flaw in the filter or is simply a limitation of DI resin...either way, I am going to experiment with making a filter that is either faster or does not require my constant attention. I am going to start by using a gallon bottle - I will fill it with the water I want to process, set a siphon going with airline tubing held in place by a hole I will make in the bottle cap of the gallon bottle, and have the water flow through the DI filter. Hopefully this will allow for constant water processing without me having to constantly be there

Ideal source water - My tap water has only 40-45 ppm TDS after I dechlorinate it, which is already quite soft and will take a while to wear out the resin...however, a lot of us have much harder water and would quickly burn through DI resin with a filter like this. Thus, I am going to see if passing old blackwater through DI resin would extend the resin's life relative to my tap water.

My experiment will go like this; I will set up two minI DI resin filters with 1/4th cup resin each. One of these filters will only be used for dechlorinated tap water; the other solely for old blackwater from the tank. I will record how many gallons of water each filter processes before the TDS of the filtered water rises to 10 ppm; if the filter processing the old blackwater lasts noticeably longer, I will recycle old blackwater through the DI resin when it is available. I will perform a similar test with my rainwater (which has a TDS of about 15 ppm after it runs off my roof).

 

HI everyone! Yesterday I planted the tank...and discovered a fundamental flaw with my substrate setup. But before I describe that, here's the tank!


The tank has Golden Creeping Jenny, Rotala H'ra, Round pellia, and Mayaca fluvitalis (barely visible behind the pellia). Parameters as of this morning (after I fertilized the tank for the day) are PH 6, TDS 14 ppm. Not sure why the PH isn't lower...I did a 40% water change yesterday and the new water I was adding had a PH in the 4's, but the tank's PH was already at 6 within minutes after I added the new water.

Anyhow, on to the substrate flaw...when I set the tank up, I placed a layer of peat moss on the bottom, a layer of leaves above that, and then the sand to keep all of that down. I had not considered the fact that if the leaves did not soften enough, they would make planting difficult...and they sure did. I wasn't able to add nearly as many plants as intended due to a lack of locations where they could be planted deeply enough; thus, some of the round pellia and Mayaca is still in the quarantine jar until I figure out what to do with it. Last night I was rather disappointed with the tank's new appearance...but this morning, now that I am more awake and less annoyed by the substrate's less than plant friendly nature, this tank actually doesn't look half bad. It will doubtless look better when the plants start to grow in.

One other thing...I was initially going to use a 1600 lumen daylight bulb on this tank. Testing such a bulb out on the tank yesterday made the tank look FAR too bright, so I switched to an 800 lumen daylight bulb.

 

Nice man. Always like following a good blackwater adventure! Good luck correcting the substrate flaw. It looks good still.

 

Nice man. Always like following a good blackwater adventure! Good luck correcting the substrate flaw. It looks good still.

Thanks! While the substrate is flawed, I don't think I am going to bother fixing it...that would make a horrendous mess. Next time I set up a blackwater tank, though, I will make a point of putting the leaves at the bottom of the substrate and putting all softer (and easier to plant in) substrate materials above the leaves.

 

HI everyone! Minor update time Today I did the tank's third weekly 40% water change. This time I added twice the recommended dose of API PH down to the new water; the tank now has a TDS of about 12 ppm and a PH in the low 5's. Let's hope the PH holds this time

The plants have also adjusted well and appear to be actively growing...I will post a picture of the tank a little later today (I meant to post a picture right now, but forgot to take a picture before I came downstairs to post this )