Tank water pH is so low, i think i need to start over..HELP

[Atl300zx]

the water in my tanks pH is very low, around 4.3 these days.

I have tried bringing it up slowly with baking soda, but it never seems to change, it just sits at 4.3, although it isnt dropping anymore. My tap water is pH of 6.3-6.5

What could be causing this? My CO2 isnt on anymore, i have two pieces of driftwood (one mounted to tile when purchased, which the other is just waterlogged and sunk to the bottom) , 1 carved rock and a good amt of plants.

Would you recommend starting over? if i did, what could i do to avoid this? Also how would i re-acclimate the fish back to the tank without killing them? i have around 20-30 fish, some as long as 5 inches.

TIA

 

[Purrbox]

Driftwood will lower you pH to varying degrees. If there's a tea color to your water when you do water changes, then the tanins being released by the driftwood are likely contributing.

The rock may or may not be an issue. You'd need to test it to be sure. Usually rocks raise the pH though.

How often do you do water changes and how large?

 

[Atl300zx]

there are no tanins in the water that i can see. The driftwood and rocks have been in the tank for about a year and my pH issue reared its ugly head within the last 4 months. They were all bought from aquarium supply stores.

50% water changes every sunday. I do EI, but only dose half as much Nitrates as recommended due to the natural bioload.

 

[gu2high]

The normal pH tests can't test pH 4.3. I hope your test is correct. If it is true, I guess one rock may cause the problem. Get each rock and driftwood in turn in a bucket overnight with tap water and test it. Also, what substrate do you have?

As far as I know, people has difficult to find a way to lower the pH. If you find the cause, then it will be very interesting.

Raising pH is easier than lowering the pH, just add crushed coral, coral, limestone and/or shell.

 

[NoSvOrAx]

Got snails?

 

[Purrbox]

How are you testing your water and have you verified your results against another test?

 

[Atl300zx]

i have a ph probe. i have verified its accuracy using 4.01 and 7.01 solutions.

i have no snails.

my substrate is seachem flourite.

 

[zacusmaximus]

Maybe try a chemical test just to be sure?

 

[gu2high]

Snails can't survive in this low pH. I have an apple snail died in a few months under pH6.8 due to shell problem.

btw, Atl300zx, the plants you gave me are growing very well, although I replanted them twice in the tank and bleach them once due to parasites infection from my local pond plants.

 

[zacusmaximus]

Practically no inverts can deal with pH this low, nor can very many fish species, for that matter. Discus, uaru, and perch can survive 5.0, but not even they will thrive in it. No other common species I know of live in naturally acid water lower than that. In nature, at the 5.0 and lower range, you usually see mass die-off because of soil-leached metal toxicity and other problems.

It might be something with the meter, but it could be lots of other things, so let's start from the top.


Some questions:


What size tank/tanks?

What is your water source? (tap, RO, distilled?)

Tank tests 4.3 and tap tests 6.3-6.5, have you tested an aged water sample or were your tap results from an aged sample? Do you have a titration-type pH test kit to verify the probe readings? The average aquaria test kit won't have a range that low but you can at least verify it's off the chart.

How often do you do PWCs? How large are your PWCs, on average?

Besides pH via the meter, what are your other water parameters (ammonia, nitrite, nitrate, pH, GH, KH, and anything else you can test for) on the tank water and/or your source water?

You said you were injecting CO2 so I would presume you are or were dosing ferts. What, how much, and how often are/were you dosing?

In your substrate bed or filter, are you using peat anywhere?

When you added Sodium Bicarbonate (NaHCO3), how much NaHCO3 per volume of water did you add? Did the meter read any rise in pH at the time the NaHCO3 was added?


I could blabber on, hypothesizing the cause of your situation, but I'll try to resist the urge and wait for you to provide some more information.

 

[Atl300zx]

What size tank/tanks?

What is your water source? (tap, RO, distilled?)

Tank tests 4.3 and tap tests 6.3-6.5, have you tested an aged water sample or were your tap results from an aged sample? Do you have a titration-type pH test kit to verify the probe readings? The average aquaria test kit won't have a range that low but you can at least verify it's off the chart.

How often do you do PWCs? How large are your PWCs, on average?

Besides pH via the meter, what are your other water parameters (ammonia, nitrite, nitrate, pH, GH, KH, and anything else you can test for) on the tank water and/or your source water?

You said you were injecting CO2 so I would presume you are or were dosing ferts. What, how much, and how often are/were you dosing?

In your substrate bed or filter, are you using peat anywhere?

When you added Sodium Bicarbonate (NaHCO3), how much NaHCO3 per volume of water did you add? Did the meter read any rise in pH at the time the NaHCO3 was added?

55 gallon

Tap water

i have not tested an aged water sample, i can do that.

i do have a titration style ph kit. i will do this, but i am pretty sure of the accuracy of my ph probe, b/c it reads 4.0 in 4.01 solution and 6.0 in a 6.01 solution.

50% water changes every sunday

ill have to do the other tests and get back with you.

i dose the following: 1/8 tsp CSM+B, Potassium Sulfate, Potassium Phosphates 2x a week and 1/4 tsp Nitrates 2x a week.

my substrate is 100% seachem flourite, i dont know if it comes with peat moss

i slowly worked up to adding 1/4 tsp per 5 gallons. the ph probe read 5.0 for a while after i started doing this, but settled back down into the low to mid 4s

i believe i answered all the questions except for the test results. i will get back to you on those.

 

[Atl300zx]

Test Results

Tank Water
pH titration test kit - off the chart (below 6.0)
pH probe - 4.7
nitrates - ~8 ppm
ammonia - 0 ppm
GH - 60 mg/L
KH - < 10 mg/L

Fresh Tap Water
pH titration test kit - off charts (7.8 )
pH probe - 6.6
GH - 40 mg/L
KH - 30 mg/L

I am aging the water for the "Aged Water Tests".

pH probe calibrated in 4.01 and 7.01 solution.

I am a little surprised the Nitrates were so low. I will keep an eye on it and increase dosing. This could explain some of the algae, I blamed it on the lack of CO2.

I was also surprised with the pH readings of the tap water. The difference between the tap water and tank water is a lot. also i don't understand the inaccuracy of the pH probe (calibrated prior to measuring and found to be accurate) versus the pH titration test kit. I assume the pH titration kit is inaccurate.

When I did the water change this past Sunday, i noticed that the pH was 5.4 on the pH probe. The pH was 4.3 before the water change. This sort of confirms the pH probes accuracy besides the calibrations.

Tank Summary:
55 Gallon
260w CF (12000k bulbs - recently ordered 2 65w 6500k replacements)
Fert Schedule
1/8 tsp CSM+B (or capful of Seachem Flourish Comprehensive - been in the fridge awhile i always forget to use it up) TuThF
1/8 tsp Potassium Sulfate MWF
1/8 tsp Potassium Phosphates MWF
1/4 tsp Nitrates MWF
Pressurized CO2 (hasnt come on because pH is so low)
50% water changes on sunday
Use Python for water changes - dose full cap of Seachem Prime after water change (bottles states that is the doseage amt for 60 gallons)

 

[Angel.Zero]

just a thought but I know some additives will make a ph reading inaccurate. Might be worth checking

 

[Purrbox]

Do you still have the 4.01 and 7.01 reference samples? If so, try testing your pH titration test against them. The 4.01 should be off the charts, but the 7.01 should be readable. This will give you a better idea of whether or not the pH titration test is accurate.

Generally Tap Water that has just been taken from the tap will have LOTS of CO2 which will cause an artificially high pH reading. Once the CO2 has gassed off, the pH reading will be a bit higher which is why you were advised to test some aged water (Tap Water that has sat for at least 24hrs) so that we could find out what your actually Tap Water pH is without the extra CO2.

What it sounds like is that you have nearly no buffers in your water (KH 30ppm or 1.7dKH) and these are quickly disappearing in your aquarium (KH <10ppm or <0.6dKH) allowing your pH to plummet. You probably weren't adding enough baking soda which is why your pH still so low. The natural pH for a KH of 30ppm is about 7.2 and the natural pH for a KH of 10ppm is about 6.8. My guess is that your KH would have to be nearly 0 to be reaching such a low pH. When water has no buffering you can get some really weird pH test results. This is why RO water pH tests can be really off the charts.

It's possible that with such a low KH, your driftwood could be releasing just enough tanins to knock out the rest of your buffering even though it isn't adding much of the tea color to the water. I would recommend increasing the amount of baking sodo you're adding, or removing the driftwood and monitoring the KH and pH to see if they start increasing with a few more water changes.

 

[Atl300zx]

Ill post the aged water tests tonight or tomorrow morning.

I will start adding Baking Soda again to the water.

Just to be sure i am doing this correctly, i am adding 1/4 tsp per 5 gallons during my water changes. So every sunday during the water change, i am adding 1 1/4 tsp. this is how you should dose baking soda, correct?

So if i were to increase this, what should i slowly work up to dosing each water change?

 

[rich311k]

You definitely want to go slowly, sudden KH changes can be hard on fish.

I find this thread interesting, my KH from the tap is maybe 1, my PH is always below the yellow on the card. I have no idea what it is. I pump in CO2 to keep my drop checker in the green. My fish are fine, nice and healthy willing to breed at a moments notice.

How are your fish doing? That is the important thing here. The plants won't care.

 

[Atl300zx]

my fish are healthy. the platys breed every month and every so often i see a new cherry barb. i have had only one fish death (runt platy) in the past 8 months. Snails dont survive long in my tank.

 

[rich311k]

You probably do not have any calcium that would kill off the snails. If I were you I would add a touch of baking sode to get up to say 3 KH. Get a drop checker for the CO2 levels forget the PH probe etc. just add the CO2, and never test PH again.

 

[Atl300zx]

how can i add calcium so i can keep snails?

 

[Atl300zx]

Confusing Test Results

Aged Water Tests
GH= 40 mg/L
KH=30mg/L
pH titration kit = 7.2
pH probe = 5.9

Titration Kit Accuracy
pH 4.01 solution = off charts (below 6.0)
pH 7.01 solution = 6.2

The titration kit vs probe seems so weird. Nothing makes sense. The probe reads 7.0 and 4.0 in the solutions, and the titration kit reads low on the 7.01 solution. The problem is everywhere else the titration kit reads high compared to the probe. I am confused!!!!! i assume the titration kit just sucks.....


A few pics since i've talked about the tank a bit