Hey guys a week ago I did a water change and everything was fine PH was sitting at 7.0 and my ammonia and nitrates were rock bottom. So today before I did my water change today I tested the water and to my shock I noticed it was sitting at 6.0. Now nothing has changed I haven't added any rocks or wood to the tank. Only thing that I did notice and took out was a dead apple snail (oh boy do they stink) could that have affected the water quality in anyway? Or can food also affect the PH? I do clean up after my O has eaten and even then he really does not make a whole lot of mess since most of the food is frozen. Any ideas guys? I will monitor the water each day for a week to see if it happens again.

well when ever anything dies it starts decompossing so that could effect your water quality as for your ph or whatever changed idk if it was cause of the dead snail someone else might know.

one thing i know is that shells of snails or clams do contains calcium carbonate
and it really affect pH of the water. a totally burned shell can produce an
acidic water when soak....

dunno if the snail could be the cause, but the ph will change when fish excretion enters the water after the fish have eaten.
Ph will often change a bit during the week, due to digested food.

Ammonia will be less toxic at a pH of 6, so that's a plus.
It's best to have a stable pH, but a pH of 6 is no problem.

Best to test and see if the change in pH is a recurring thing.

I do keep my waterhardness (kH) stable at 7.
I learned that a stable kH at 7, will help keep your pH stable.
But i must admit that i'm one of the few members who makes use of this trick.
I started out in the hobby with plecos, and they require a stable pH ,even more than Oscars.
Plus altering your kH will not harm your fish, as long as it's done slowly.
Opposite to altering your pH, which can be very harmfull to your fish and is not to be advised.

PAUL wrote:


Yeah I was thinking that too bad then it seems the snail was not dead for very long maybe 3-4 days and the shell was not empty hence the terrible smell.

Noddy wrote:


Thanks my KH is pretty low and stable out of the tap never had issues there, maybe it is because I have added new foods to my Oscars diet I regularly check my PH and do all my water tests and it is the first time I have seen this but I will keep my eye on it thanks.

larch wrote:

KH is at 3 with our tapwater and that's a bit too low imo.
What is your reading for KH?

Noddy wrote:


Between 5 and 6 is that too high? if so what methods can I use to lower and raise it?

i would do as noddy suggested. retest after water changes. do a few water changes at a time try not to do very large changes if the tap ph isn't close to tank ph.

marcus wrote:


Thanks Marcus I will did a water check this morning and it was at 6 again...so I did a small water change cleaned my powerhead and canister filter (with some tank water of course) I have a suspicion it might be the new food I am giving him that is maybe too rich for him so he ends up just putting it back into the water.

Every now and then i used to have my ph fall from 7 to 6 with no changes to decor food or water changes. I put a small amount of crushed coral in the filter and i find my ph never drops below seven. I believe you have to find the right amount of coral for your system because if you put too much in it will raise the ph up into the 8s and if you dont put enough in it will do nothing. There are also buffers that are supposed to keep a stable ph but i do not have experience with these to tell ya if they are good or not.

Capt Dave wrote:


Thanks Capt Dave, but I believe I found the issue(s). Firstly it seems to be the new diet I have been giving my Oscar, seems his system did not digest it 100% so he ended up passing it right back into the water. 2nd I haven't cleaned my canister filter for well over 2 months. So after reverting back to his old diet and cleaning the canister my readings have stayed stable for the past 2 days.