Ph keeps dropping, what am I not seeing?
My tank has been up for about a month and so far everything has been going as expected. But over the past week my pH has been dropping out of the blue and I can't see a reason for it. After my water change yesterday my pH was 7.4 and now it has dropped to 7. Anyone have any ideas what is going on?
General Tank Specs:
3.5 gallon tank with Caribsea Floramax substrate. Not fully cycled yet, but ammonia has been zero for at least a week now. I did have a spike on 2/2 to .25 ppm, did a water change and its stable at 0 again so far.
Inhabitants are a betta and two nerites. (I know the two nerites are too much for the tank, I've been trying to get rid of one or both of them but the person I was going to give them to bought a snail eating fish and didn't tell me)
Nitrites have consistantly stayed under .25 ppm with water changes either every few days or when they hit .25 ppm
Nitrates have never gone higher than 5 ppm and are almost always under.
KH and GH have really only been tested once, they were about 4 dkh and 8 dgh a few weeks ago, KH looks like it has dropped to 2 dkh as of 1/29.
My tap water has a pH of about 8, and the KH/GH match my first water test. I started out using pH down, aiming for a pH of 7.2-7.4, but have decided thats silly and I have been trying to slowly raise the pH as I do water changes. The pH drops started just before I began reducing my use of pH Down.
Dosing a couple ml of Aqueon liquid fertilizer every now and then, about twice a week but no set schedule.
Oh and plants! Anubias frazeri, lobelia cardinalis (dwarf), dwarf hairgrass (i forget the scientific name) and a few El nino ferns that are desperately trying to reproduce before they die.
And here are the measurements I've taken over the past weekish:
1/24: pH 7.2 Ammonia 0 Nitrite 0 Post water change.
1/26: pH 6.6 Ammonia 0 Nitrite >.25
1/26: Ammonia 0 Nitrite 0. Post water change. Began reducing pH down usage
1/28: pH 7.2 Ammonia 0 Nitrite > .25 Nitrate > 5
1/28: pH 7.2 Ammonia 0 Nitrite 0 Nitrate ~0 Post water change. Fertilized
1/29: pH 6.8 Ammonia 0 Nitrite >.25 KH 2 dkh
1/31: pH 7.2 Ammonia <0? Nitrite .25 Nitrate >5
2/2: pH 7.0 Ammonia .25 Nitrite >.25
2/3: pH 7.4, others assumed zero Post water change. Fertilized
2/4: pH 7.0 Ammonia 0 Nitrite >.25
I know that KH is supposed to buffer against pH drops and that the drop in KH is likely related, but I can't figure out what is making either of them drop. Could it be the snails taking calcium out of the water?
Last edited by _mdc_; 02-04-2018 at 11:56 PM.