pH stuck on 6.0-6.2 with Zero KH and High GH

Hello,
So it is freshwater 26 gal tank, several live plants, small fish (flock of 10 red neone, two black neon, pair of sword, total 20 fish around 1/2 to 3/4 inch long) - see pic. Ammonia=0.25, Nitrite=0, Nitrate=40-80 (hard to tell from the API test color chart). It's 43 days since setting up (from scratch).

Now, no matter what I do including:
- partial 15% water changes every week (last 2 weeks after tank got cycled) , I use drinking water since I learned Florida tap water is really bad)
- adding Seachem Natural regulator
the acidity stays at 6.0-6.2 hard to tell based on API chart).

The Seachem initially brings it down to 7.0 but next day it comes back to 6. Same with water, tried tap water, drinking water, even ORP one time, it keeps it at 6-6.2. I have Fluval softening granules in one of my 2 filters (Fluval 70 + Fluval 106), read this one can bring water acidity up so I removed it at some point but it did not change the pH at all, use of Natural Reg. brought it down to 7 and then next day back to 6 again. I put softening granules bag back to filter as my GH is really high- per API test it is 11 drops which translates (I suppose because instruction for this test is bad) to 200ppm (?) while my KH is ZERO. Is it even possible? All tests have expiration date in 2021.

Btw, I had serious problem initially with getting rid of Ammonia which got locked in first 2 wks after tank was setup up with something I won't use again EVER, the API Ammo-Lock, which I learned was one of the mistakes I made extending my cycle forever. Finally after many tries with commercially available bacteria products from different brands - none of these worked, I stumbled upon Fritz-Zyme 7 and after adding it, the Ammonia dropped from 8.0+ to 0.25 in few days and it stays low until this day.

My fish looks happy, play around all day, chase, I actually got the pair of Corydoras paleatus spawned the other day, one of them laid eggs under the plant leave but they got all eaten shortly after that.

I read adding baking soda is good way of bringing pH up instead of using Seahem natural regulator which contains some other chemical which can throw the pH off if overdosed. But should I really worry and mess with it after long cycle and struggle to get ammonia out of the tank? I appreciate suggestions. Thanks for reading

 

Welcome to fishlore! CindiL can help you.

 

Thanks, will look at CindiL posts then.

In the meantime, I appreciate everyone's opinion and pointers on the subject.

 

Hi, welcome to fishlore

The water softener pillows will help lower GH but I don't think its necessary honestly. My GH is at 10 drops and my tetras and cories are as happy as can be, the cories are going on a couple years old now.

Wow, a KH out of your tap at 0? That is unusual. If you cycled with your tap water and your fish are fine, I would just keep using tap water and save yourself the hassle. The problem with a KH of 0 is not only does your PH drop, but it can easily crash and your fish can die plus the nitrogen cycle bacteria pretty much stop multiplying when it gets down to 6.0 and are greatly reduced even at 6.5.

What I would suggest is a couple of things. Right now I would take 1/2 tsp baking soda, mix in with a little tank water then pour it into your tank. Test after an hour or so, dose it again if need be to get it up close to 7.0.

Then, I would go to your local pet store and pick up one or some of the following:
crushed coral, aragonite, limestone, a piece or two of cuttle(fish) bone in the bird section (no flavors, dyes and remove the wire), sea shells, oyster shells etc.
Put a media bag into your filter of about 1/2 cup of the shells or you can mix into your substrate. What this will do is help stabilize your KH between water changes and will prevent a PH crash and hold it stable. I would add in the baking soda at every water change, a small amount. You want to aI'm for a KH of a minimum of 5 drops.

Long term, Seachem Alkaline buffer is a great product and what I use and will do the same thing as the baking soda but has both carbonates and bicarbonates.

 

Dear CindiL, thanks for reply and great pointers. It's great to learn more from experienced owner and find that lot's of missing pieces of this puzzle coming together.

Before I added soda , I repeated pH, KH and GH measurements for tank water, tap and drinking water which I used in past 2 weeks in partial water replacement. Here are results:

1. existing tank (aquarium water)
pH=6.2 (light yellow)
KH=1 (just one drop makes the target color, I refer to it as 0 before)
GH=11 (same as this morning)

2. tap water
pH=7.6
KH=3
GH=5

3. Drinking water
pH = 6.2 (same as water in aquarium)
KH=1 (same as water in aquarium)
GH=3 (aquarium is 11)

Again, I used drinking water 1st time 2 wks ago when I replaced 4 gallons. Then week later I replaced another 4 gal. The tank has about 22 gals (26 gal minus lots of gravel, etc.)

I added flat tsp of baking soda, while we wait for the result, I list below water parameter changes I registered daily for past 40+ days after setting up the tank (I use Aquarium Note app on my phone).

pH
day 0: tank setup with 100% of tap water (temp was always between 73 and 75F), conditioned with Safe Start and Stress Coat.
day 1: pH=7.6, next days I used API pH Down to bring it down but it kept coming back to 7.5+ until after 2 wks I added softening bag. Then in 2 days pH went down to 6-6.2. I am not sure if this was coincident but I removed the softening bag after this pH went down. Since then the pH stays around 6.2 no matter what I do (I did nothing actually waiting for ammonia to go down).

NH3 (Ammonia)
day1: 1.5ppm
day2-7: ammonia ppm climbing
day6: 8ppm (panic mode, added API Ammo Lock for few days)
day8-26th: 8+ppm , adding Seachem Stabilizer
day 27th: 8+ppm (1/2 fish dead by now, rest is fine)
day 28th: adding Fritz Zyme 7
day 29th: 4ppm
day 30th: 2ppm
day 31st: 0.5ppm
day 35th: 0.25ppm (until today). Fish are happy, no issues with lifestock.

NO2 (Nitrite):
day1: 0.25ppm
day24th reached 2ppm
day 35th: goes back to 0ppm, stays there until today

NO3 (Nitrate):
day1: 0ppm
day14: 0ppm
day15: 7ppm
day16: 10ppm
day 28th: added Fritz Zyme 7
day 30th: 50ppm and stays until today.

KH
day 7th (this is when I tested KH 1st time) 5 drops
day 18th: 3 drops
day 30th: 1 drop, stays this way until today

GH
day 7th: 6 drops
day 10th: 8 drops
day 16th: 10 drops
day 30th: 13 drops
day 33th: 14 drops (installed softening bag)
day 36th: 12 drops
day 43th (today): 11 drops

Summary as of today (43 days from setup)
pH=6-6.2, NH3=0.25, NO2=0, NO3=50, KH=0, GH=11

Now, around 1 hrs after adding baking soda, the pH went up to 6.4. I guess I can add another dose per your suggestion. And retest. I also have cuttlebone , will crush it and add to filter media basket. In the meantime, I appreciate your thoughts based on the above.

What is interesting is:

GH went up dramatically from 5 to 11 in 40 days.
KH went down from 5 to 1 (0) in 40 days
pH went down drom 7.6 to 6-6.2
NH3 cycle was extremely long (I was told this is because of use of Ammo Lock at some point which extends the cycle time), actually NH3 went down only after adding significant amount of Fritz zyme 7 (5 cups for 22 gals of water).

 

Ok, there is something in your tank that raises your GH (mineral salts), what kind of substrate do you have. Again, I wouldn't worry too much about the GH. I would go back to using your tap water.

The reason your tank (most likely) took long to cycle was because of your low KH and PH and not because of the Ammo-lock as people use this product with fish-in cycling and it doesn't prevent the cycle from completing. I see this all the time here.

KH gets used up by the nitrogen cycle which is normal. The nitrogen cycle is acidic and uses up the carbonates. Because yours are so low they get used up fast and then cannot hold your PH steady. It is definitely what I would expect from a KH that looks like yours.

You don't have to cut up the cuttlebone, you can actually just put it whole into your filter if you want to.

I would do at least 30% water changes weekly, (more is better) which will help replenish some carbonates and minerals and reduce your nitrates. You want to aI'm to have your nitrates below 20, so yours are too high where they're at.

Never use PH down, throw it out

Let me know if you have any more questions.

 

History of my tank on the chart (click to zoom)...





@CindiL, thanks a lot, I made checklist from your valuable post:

> what kind of substrate do you have.
River rock type from two vendors, both for aquariums: one at the bottom is Cumberland River Rock purchased in Petsupermarket, second is Petco Aquarium gravel I have on the top. both washed thoroughly multiple times (at least 5 water changes) in room temp tap water and drained before installed. Nothing suspicious there.

> I would go back to using your tap water.
Check. Will do.

> You don't have to cut up the cuttlebone[...]
Yes, I put the whole piece in my F70 basket under the Bio cubes to hold it down.

> I would do at least 30% water changes weekly, (more is better) [...]
Check. OK. Just wondering about tank cycling, would it destabilize it again?

> Never use PH down, throw it out
Gone!

Little scared to change that much water, after I went through with the fish stock, finally got these all happy with one spawned. But I know leaving it as it may result in another trouble that is yet to come. I will continue water changes and observe cuttlebone effect.

Oh, almost forgot, the pH went up to 6.8 after another dose of baking soda. Will re-check tomorrow morning. In the meantime, let me know if there is anything else we can do.

One more thing, the gravel is vacuumed once a week with water change, but to be honest there is almost no debris, it all seems to be sucked into the filters as I have two over-sized installed, Fluval AquaClear 70 and canister 106. I checked both about 2 wks ago and they both had all the feces and all dirt sucked into the 1st stage sponge which I cleaned leaving Bio rings and everything else intact. I also installed internal bio sponge filter (old school) to increase biosurface. Hope this is not an overkill but I wanted to maximize bio surface in my tank filtration system.

P.S. I posted some pictures of my setup in user gallery. I am showing some items like artificial ornaments that are installed besides the gravel. I do not suppose they change water chemistry (as made from plastic) however since you pointed out concern about gravel, I felt like sharing all other pieces of my setup. Thanks for looking.

 

Hi, your cycle is contained for the most part in your filter media and some on the surfaces of your tank like your substrate etc. Very little if almost none is contained in the water column, so once cycled you can do a 90% water change (if you wanted to) with no effect to your cycle. The larger 30% will be just fine and when you're comfortable with that, I'd encourage 40% even
Your fish will get used to it and come to really like it.

The only thing I can figure with the GH is food etc adding to the mineral content of the tank because your rocks seem ok.

That's good that the PH went up some as it was so low! Wouldn't want to see you have a cycle crash.

Bio-surface is always a good thing! I'd aI'm to clean the easy to get to filter media weekly to remove food, poop etc as that contributes to nitrates. Do your cannister as you can, I know those are harder to take apart and clean.

I will have to look at the pics tomorrow, do you have a link?

Thanks for the details it has been very helpful.

 

Next day update:
- just 11 hrs with cuttlebone installed raised KH from almost 0 to 5 (drops). I removed it, should I?
- GH slowly but keeps dropping, today is 10 drops.
- pH maintain 6.8 after dosing baking soda yesterday.
- NH3 is still 0.25, NO2=0, still high NO3 (40-80) hard to tell based on API chart, no change here.

I appreciate comment CindiL . Thanks for reading.

 

Next day update:
- just 11 hrs with cuttlebone installed raised KH from almost 0 to 5 (drops). I removed it, should I?
- GH slowly but keeps dropping, today is 10 drops.
- pH maintain 6.8 after dosing baking soda yesterday.
- NH3 is still 0.25, NO2=0, still high NO3 (40-80) hard to tell based on API chart, no change here.

I appreciate comment CindiL . Thanks for reading.

That's awesome about the KH, leave the cuttlebone in. Because your ph was so low it dissolved minerals into the tank (from the acidity), that will slow down as your ph and kh become more stable and your kh won't get too high, don't worry about that.

I would start doing water changes today. Nitrates are the end result of the nitrogen cycle and is one of the reasons we do water changes. With your nitrates where they are at, I'd really aI'm for a couple water changes today which help increase your ph also. Match temperature and add in some baking soda after the water change. Do them daily until the nitrates are under 20.

 

CindiL
Should I condition tap water before using for tank (remove chlorine, etc.)? What would you recommend to use for this? I appreciate letting me know, thanks.

 

Yes, always condition the tap water, if you forget it could kill your fish or your cycle, depends on how high the concentration of chlorine or chloramines are in your tap. I'd recommend Seachem Prime.

 

Yes, always condition the tap water, if you forget it could kill your fish or your cycle, depends on how high the concentration of chlorine or chloramines are in your tap. I'd recommend Seachem Prime.

Yes, I always add conditioner when using tap water but this time before I do that I was wondering how do I determine chlorine concentration to add proper amount of prime? Thanks.

 

The regular dose will take care of normal concentrations of chlorine. You can either dose it by the bucket or I just dose it for the whole volume of water in the tank, e.g., 25g is 1/2 capful as it takes so little.

 

Quick update beforewater chage. pH holds 6.8, KH holds 5. NH3 is finally 0. NO2=0, NO3=40/80 no change here.

Water became slightly cloudy as before was crystal clear.
Hope nothing to be concerned about. Fish look happy.

I am about to perform 30% water change per CindiL . Will update after that. Thanks.

 

If there is any food in the substrate, it may have been stirred up which gets the bacteria multiplying into the water column, thus some cloudiness. It should resolve on its own. Have you tested your tap water for nitrates?

 

CindiL: unlikely, the cloudiness appeared before water change, before I did any movement in the tank. It appeared day after rising pH with baking soda and cuttlebone installation.

Now on water change subject.

Tap water params (sample straight from tap, before conditioning):
NH3=1.0 (!)
NO2=0
NO3=0
pH=7.6 (8.4 per high range)

30% change with vacuum

Tank 2 hrs after change:
pH=6.8
NH3=0.5 (!)
NO2=0.25
NO3=40/80 (same intense red, no effect - water change)

So my tap water did not affect my tank NO3 at all, but it threw my NH3 up from 0 this morning to 0.5.
I really have no clue what is happening with NO3 here, make no sense. Test kit exp.date is 2021.

Tap water NO3 is 0.

 

I would take a sample of tap water, add conditioner and re-test ammonia. The reason you have ammonia in your tap water is because your water provider is using chloramines. Chlorine + ammonia = chloramines, when you break the bond with your water conditioner you will be left with ammonia as it will take care of the chlorine.

Just make sure to dose prime for the full volume of the tank at every water change, it will detoxify that ammonia (+ nitrites) up to 1.0 for 24 hours. If they're not gone by tomorrow (which they should be), then re-dose prime again.

The reason you're not registering a change in your nitrates is because they are so high that your water changes are not making a difference. What was your ph after your water change?

I would continue to do water changes and once your ph is close between tap and tank then I would do larger 50% changes to make a bigger effect on the nitrates. If its on the high range test then that is the only test you need to do.

 

I would take a sample of tap water, add conditioner and re-test ammonia. The reason you have ammonia in your tap water is because your water provider is using chloramines. Chlorine + ammonia = chloramines, when you break the bond with your water conditioner you will be left with ammonia as it will take care of the chlorine.

Just make sure to dose prime for the full volume of the tank at every water change, it will detoxify that ammonia (+ nitrites) up to 1.0 for 24 hours. If they're not gone by tomorrow (which they should be), then re-dose prime again.

The reason you're not registering a change in your nitrates is because they are so high that your water changes are not making a difference. What was your ph after your water change?

I would continue to do water changes and once your ph is close between tap and tank then I would do larger 50% changes to make a bigger effect on the nitrates. If its on the high range test then that is the only test you need to do.

I am not using Prime because I do not have it. What I have and use is Tetra AquaSafe+ to condition water before adding. The pH did not change after water change, it is still 6.8, I listed this in my previous post along with other parameters.

After 3 additional hours, the NH3 is somewhere between 0.25 and 0.50, seems like around 0.35, so it is going down. Fritz Zyme 7 does the trick as before so I expect ammonia to be 0.25 or less by tomorrow morning. Thanks Fritz! Thanks CindiL, I will keep posted.

Checking in after weekend (3rd day after 30% water change):

pH=6.8 (holds steady)
NH3=0
NO2=0
NO3=50 (no change)
KH=3 (cuttlebone still in)
GH=7

I ordered Matrix and plan to install next in my 2nd filter. Any other suggestions on how to deal with NO3 appreciated.

 

Am I reading that right that your nitrite is up to 2.0? I am way more worried about that, I would do a 75% water change or two back to back 50% right now as the nitrites deprive them of oxygen by bonding to their blood, also known as brown blood disease.

I would pick up that seachem prime as it will detoxify ammonia + nitrites up to 1.0 when dosed every 24 hours for the full volume of the tank.

Also, I know you like Fritz Zyme but it is not the right type of bacteria you need for cycling, it is a bottle of heterotrophs, organic decomposing, not true nitrifyers. I would pick up some Seachem Stability.

 

I am so sorry for the typo CindiL, the NO2 is 0.

I do have Stability but my experience is poor with it as it was never able to drop ammonia when it was high, unlike zyme7 which when added took care of NH3 right away.

With zero NO2 and NH3, I am sure I do not need to worry about bacteria, the tank is cycled. I hope Matrix will help to reduce NO3, after what I read in separate thread on this forum, along with other methods, it worked for some of users.

 

Ok, phew!
I use Matrix which is a good product. I would still do a 50% water change to start seeing results with those nitrates. They must have been awfully high.

 

Ok, pardon me for being cautious but for 50% water changes, won't it ruin the biological balance to the point my tank would have to cycle again?

 

Ok, pardon me for being cautious but for 50% water changes, won't it ruin the biological balance to the point my tank would have to cycle again?

Nope, the majority of your nitrifying bacteria live in the filter materials which is why its so important to rinse them in old tank water or dechlorinated tap. Some live on your substrate and decorations, virtually none live in the water column. There are very small numbers as they multiply and before they attach to a surface. They don't, however actually live in the water. I have had fish for years and routinely do 50-75% weekly water changes and have had swapped my tanks many times with brand new water, only moving the filters and decorations and never have had any issues with my cycle.

 

Thanks CindiL
Ok, I did my homework today, 40% water change with detailed vacuum of the gravel throughout, no more debris, just gravel, tap water conditioned with Tetra AquaSafe+. After change I also added Stability per instruction. Here is water in tank after change:

pH=6.8
NH3=0.5
NO2=0.1
NO3=40/80 (still vibrant red)
KH=3
GH=5

I pray ammonia drops over night as before. I removed last plastic plant and one of two plastic decorations. Tomorrow I am supposed to get Matrix, plan to fill one of two trays of canister in my second filter Fluval 106. I have not touched my 1st filter neither 3rd bio sponge internal filter.

Morning update, 10 hrs after water change :

pH=6.8
NH3=0.1
NO2=0
NO3=40/80 (no change)

 

Ok, great! Is the cuttlebone still in there? I would leave it in and I would be dosing baking soda with your water change. You want to see your KH come up to close to 5.

I would keep doing the water changes daily to get those nitrates down. Start doing 50% water changes as you feel more comfortable If they're bright red they were off the chart to begin with. They will come down if your tap water is 0. Feed sparingly for a few days.

Rinse any sponges that you haven't in the last couple of weeks in old tank water, swish them around and get any old food and poop off of them. All of this contributes to high nitrates. I'm glad you did a thorough clean of your substrate too.

 

CindiL
Yes, cuttlebone is still there. I have seachem alkaine buffer delivered, shouldn't I be using this instead of baking soda?

Should I clean sponges by rinsing it under flowing tap and then soak with old tank water before reinstall ?

I have 500g of Fluval BioMax split in two filters and I am not touching that of course. Neither I am touching internal biosponge filter, it does not seem to have too much waster in it as most of it is sucked by my two main filters.

 

No, I would still just swish it around in old tank water. Any chlorine will kill off your nitrifying bacteria which we don't want.

And yes, use alkaline buffer

 

No, I would still just swish it around in old tank water. Any chlorine will kill off your nitrifying bacteria which we don't want.

And yes, use alkaline buffer

Ok. I just added 7 grams of alkaine buffer, the result is KH went up from 3 to 6 with slight change to pH which is now around 6.8-7.

Will keep monitoring. And plan to do another water change tomorrow.

Btw, I also happen to have jar of seachem Neutral Regulator, never used it before. What's the difference vs. Alkaine buffer? The back label does not say about KH, just about pH, unlike Alkaine buffer where both pH and KH are addressed. I appreciate comment.

 

Perfect with KH numbers now.

Yes, you're right, Neutral regulator does not increase your KH which we want to do. It is phosphate based. It softens water so my guess is it might decrease KH though I haven't tested that theory. I don't see a use for it unless for some reason one felt they had to get their ph from 7.5 to 7.0 or something similar but even in that case I wouldn't recommend it. Maybe there is a situation where it would be warranted, not sure, but not in yours

 

Thanks @CindiL. I stick to Alkaine Buffer then.

Quick update. I just installed 1/2 litre of Matrix rock in one of two filters I have. I hope with this and water recommended changes, my nitrates will finally drop. Is it true, the Matrix works best in low flow filters?

In the meantime, the water quality battle turned my little setup into chemistry lab

 

No, you're probably thinking of de-nitrate their other product. I have matrix in my filters and it does help but it takes 3-4 weeks to work and I personally feel helps prevent the rise of nitrates from being drastic. If I was use I would get API Nitra-zorb, it will bring your nitrates down in a few days if they actually register on the test, you may not notice if they're still so high they aren't registering. Lots of people have been very happy with that and its easily re-chargeable with regular aquarium salt. I would keep doing the large daily water changes until they're down, then after that, 40-50% a week.


https://www.fishlore.com/aquariumfishforum/threads/review-of-nitrate-reducers.217267/
Here is a thread where we discuss nitrate reducers if you haven't seen it yet:

 

No, you're probably thinking of de-nitrate their other product. I have matrix in my filters and it does help but it takes 3-4 weeks to work and I personally feel helps prevent the rise of nitrates from being drastic. If I was use I would get API Nitra-zorb, it will bring your nitrates down in a few days if they actually register on the test, you may not notice if they're still so high they aren't registering. Lots of people have been very happy with that and its easily re-chargeable with regular aquarium salt. I would keep doing the large daily water changes until they're down, then after that, 40-50% a week.


https://www.fishlore.com/aquariumfishforum/threads/review-of-nitrate-reducers.217267/
Here is a thread where we discuss nitrate reducers if you haven't seen it yet:

Oh gosh, so many products to choose from. So De-Nitrate would work better than Matrix in my case?

I also wonder how Matrix gets populated with bacteria that supposed to reduce NO3? I heard only plants or water changes (besides some chemicals) can reduce nitrates. Isn't that bacteria should be planted onto the Matrix? It is just a dead rock so how come it can develop NO3 reducing bacteria? Just curious.

Yes, I read this interesting article and here is where I stumbled upon Matrix rock. I also read about this expensive Natural Nitrate Reducer from Instant Ocean, do you believe it could help to drop my nitrates faster?

 

Oh gosh, so many products to choose from. So De-Nitrate would work better than Matrix in my case?

I've been very happy with matrix and de-nitrate needs a super slow filter which matrix doesn't. I have a pound of matrix in my pond filter and nitrates never rise more than 5ppm a week with 4 4-5inch messy goldfish.

I also wonder how Matrix gets populated with bacteria that supposed to reduce NO3? I heard only plants or water changes (besides some chemicals) can reduce nitrates. Isn't that bacteria should be planted onto the Matrix? It is just a dead rock so how come it can develop NO3 reducing bacteria? Just curious.

Its a good question! The end of the nitrogen cycle is nitrogen gas which is released into the air and rarely occurs in an aquarium because it requires zero oxygen as it is anaerobic bacteria. Just like regular bacteria grow on their own in our aquarium so would anaerobic de-nitrifyers if provided the right environment. Matrix has small enough non-oxygenated spaces inside the material itself to house anaerobic bacteria which is why you don't see results for a few weeks because they have to grow. I have been happy with it though. My aquarium goes up by 5-7ppm a week and I'm currently 85% stocked.

Yes, I read this interesting article and here is where I stumbled upon Matrix rock. I also read about this expensive Natural Nitrate Reducer from Instant Ocean, do you believe it could help to drop my nitrates faster?

I have tried them all and they all work, there are pros and cons to them all. Matrix is a no brainer because you put it in and leave it be plus it can serve double duty as your ceramic media for nitrifying bacteria also. Nitra-zorb works great but needs to be re-charged almost weekly (in your case) with such high nitrates right now but it definitely works.

Natural nitrate reducer worked for me also. Usually took a couple days but then I'd see nitrates start falling and barely go up when I used it.

 

I have tried them all and they all work, there are pros and cons to them all. Matrix is a no brainer because you put it in and leave it be plus it can serve double duty as your ceramic media for nitrifying bacteria also. Nitra-zorb works great but needs to be re-charged almost weekly (in your case) with such high nitrates right now but it definitely works.

Natural nitrate reducer worked for me also. Usually took a couple days but then I'd see nitrates start falling and barely go up when I used it.

Thanks for pointers. I will try natural nitrate reducer. In the meantime here is tank water parameters night after adding Alkaine buffer:

09/14 Wednesday
Temperature: 25 °C
pH: 7.2
Ammonia: 0 ppm
Nitrite: 0 ppm
Nitrate: 40/80 ppm
KH: 5 drops
GH: 5 drops

It look like pH went up significantly. I hope it won't climb anymore. Remember, it was just 6.0-6.2 before we added baking soda few days ago.
But the KH and GH are perfect now it seems.

My fish looks happy including one guppie which was not feeling well in past two days swimming right under the water surface, today I saw him back in shape with other fish flying through entire water column.

 

Good news, that looks perfect for KH, your GH is still low for the guppies, though glad he is perking up now, how many guppies do you have? I'd think about getting Seachem Replenish if you'll be keeping guppies or other live bearers long term.

 

Good news, that looks perfect for KH, your GH is still low for the guppies, though glad he is perking up now, how many guppies do you have? I'd think about getting Seachem Replenish if you'll be keeping guppies or other live bearers long term.

I had 3 guppies, one did not make it about 10 days ago, it all started from same behavior keeping itself uderneath water surface, now the 2nd one started to do the same. Both females. The 3rd male looks healthy chasing both orange swords all around.

Interesting you say, the GH 5 is bad for guppies, I always thought it is high general hardness which contributes to poor fish health.
My other fish including: flock of 10 Inessa neon plus 2 black neon, 2 danios, one red tetra and one black striped tetra plus couple of bottom keeper corys are doing great since day one my tank was established.

Update:
I am about to perform another 40% water change, here are parameters of tap water after dechlorination using tetra AquaSafe+ :
pH 7.6
pH high range 8.0
NH3 0.5
NO2 0.1
NO3 0
KH 5
GH 5

I am concerned about its alkalinity and NH3 content, should I ? Or should I wait till tomorrow when I get Prime delivered and use this to condition water instead of tetra liquid?

 

Yes, most fish do great with your GH. Livebearers though like some African Cichlids require alkaline hard water for proper osmotic functioning. Often in water that is too soft they will develop what is known as the shimmies where they shake or vibrate and swim drunkenly. It is easier to keep soft water fish in hard water then vice versa.
Did you already do your water change? Your bio filter will easily handle the ammonia though prime will detoxify it while it's converted which is a good thing.

 

Did you already do your water change? Your bio filter will easily handle the ammonia though prime will detoxify it while it's converted which is a good thing.

Not yet. I mentioned, I am getting Prime tomorrow. Today I have two 5gal buckets conditioned with Tetra AquaSafe+, not sure how to compare it with Prime therefore keep using it this last time

 

They do the same thing as far as water conditioning goes. Prime just does the extra step in detoxifying ammonia plus nitrites up to 1.0.