Unknown pH drop?

[myo]

Hi all,

Have a lightly planted 6 foot tank which seems to be a considerably lower pH to the tap water.

Our tap water reads at a pH of 7.4 and my other tanks are showing higher (Cichlid tanks). The planted tank is as follows:

pH: 5.8/6.0
Ammonia: 0
Nitrite: 0
Nitrate: 5ppm
KH: 1° (first drop turns it yellow)

Lightly dosing with flourish, excel and nitrogen for plants. And prime for water changes. It’s due a change but would be interested to know what’s causing the pH to drop!

 

[eternal_irony]

Have you got any wood in the tank? Even if it isn't staining the water, driftwood leaches tannins for a long time and can cause a PH drop

 

[myo]

Only a small amount. Not noticed such a drop before

 

[fishytank]

Im not sure of the why(cause), but if you want to raise the PH and keep it raised add some crushed coral as this will at least keep your PH where you'd like it.

 

[BBradbury]

Hello myo...

Apparently, one or a combination of the chemicals you're putting into the tank water is affecting the pH. Do the plants you keep require supplements? Most low to moderate light plants don't require added nutrients. They'll do fine with what's provided by the fish. What's your water change routine. If you're not removing and replacing most of the tank water every week, you should work up to this point. This will help maintain a steady water chemistry.

B

 

[ZxC]

What is your substrate?


Do you use CO2?

 

[myo]

Just gravel as substrate. No co2.

Plants are Anubias, java fern, mosses, etc.

Been using all the Ferts for months and never seen this happen before.

 

[myo]

Annoying because if I could get it to balance at around 7 I want to keep discus. [emoji23]

 

[ZxC]

What rocks and substrate are in the cichlid tanks? What pH reading are you getting out of those tanks?


How big and frequent are your water changes?

Likely your low kH is causing issues.

 

[myo]

Cichlid tank has limestone and crushed coral and has pH of about 7.6.

Doing a 50% water change once a week, heavy filtration and only light stocking.

KH is crazy low, normally about 6 or 7°

 

[ZxC]

Cichlid tank has limestone and crushed coral and has pH of about 7.6.

Doing a 50% water change once a week, heavy filtration and only light stocking.

KH is crazy low, normally about 6 or 7°

Well the lime and CC is why those tanks have a higher pH.

I would assume the low kH in the other tank allows the cycle to produce CO2 and other humic acids that will drop the pH, plus a small peice of driftwood.

You can try aiming for 1-2 degrees of kH using KHCO3 and this here website:

https://rotalabutterfly.com/nutrient-calculator.php

do this slowly, maybe add 0.5 degrees into your incoming new water during a 50% water change, then 1.0 degrees into the following weeks water change.

I would test tapwater kH to confirm before starting to play with pH.

if the pH is stable at your levels don't worry about it, if it is swinging around then a little kH will help calm things down.