PH Issue

[Bwhite85]

Hello! I have 4 fish tanks - one 55 gallon, two 10 gallon and one 5 gallon. Across the board I am having an issue with KH and PH. The 5 gallon is the only one holding steady right now but it’s empty because the PH crashes killed all the shrimp and I moved the betta. The other three have different stocking and planting. The two ten gallon have lighter planting and light stocking. The 55 gallon is pretty heavily planted and stocked. Probably too heavily stocked right now. I will do a water change and the KH and PH will be 2-3 and 7-7.5, but by day 2 after the water change, the KH is zero and PH is 6 but possibly lower because my liquid test kit bottoms out at 6. I have crushed coral in all three tanks. I’ve used buffers. I have done hours of reading and gone to a speciality fish store for help, but they were stumped also. I have no idea what is causing this and I have no idea how to fix it. I’m so frustrated.

 

[tinylostwine]

I'm not sure why you think the ph dropping is what killed the fishes. How long did you have the fishes before they died?

While stability is important - once it drops if you just leave it down there on the floor it should be fine providing you keep fishes that love soft water. Can't say much about your betta but wild betta love water to be as soft and acidic as possible. Shrimp - i don't know anything about shrimp other then they require some minerals for their shells.

 

[Bwhite85]

The shrimp died. I purchased the tank fully established and when I refilled it with local water, the chemistry swing killed them. The issue is when I do water changes, the PH goes back up then drops again quickly. If I could just keep it stable, it would be less of an issue, but water changes force these swings. It’s been fine for my fish, but it’s not good for the shrimp.

 

[TClare]

Perhaps do smaller, more frequent water changes?

 

[tinylostwine]

Have you tried letting your water sit in a pail overnight before using it for a water change ?

 

[Bwhite85]

No, but I can try that and see what happens.

 

[AnilS]

Hello! I have 4 fish tanks - one 55 gallon, two 10 gallon and one 5 gallon. Across the board I am having an issue with KH and PH. The 5 gallon is the only one holding steady right now but it’s empty because the PH crashes killed all the shrimp and I moved the betta. The other three have different stocking and planting. The two ten gallon have lighter planting and light stocking. The 55 gallon is pretty heavily planted and stocked. Probably too heavily stocked right now. I will do a water change and the KH and PH will be 2-3 and 7-7.5, but by day 2 after the water change, the KH is zero and PH is 6 but possibly lower because my liquid test kit bottoms out at 6. I have crushed coral in all three tanks. I’ve used buffers. I have done hours of reading and gone to a speciality fish store for help, but they were stumped also. I have no idea what is causing this and I have no idea how to fix it. I’m so frustrated.

That sounds so frustrating, sorry. When KH hits zero in 2 days in every tank, I’d suspect your tap water is very soft and has almost no buffer, so the tanks use up whatever little KH they get.


I’d test your tap KH and GH first, and your nitrates too. Nitrates build up fast in a heavily stocked tank, and the process behind them eats KH. Crushed coral is also slow and often not enough by itself.


What I’d try is buffering the new water before it goes in the tank, so you start at a steady KH every time. Smaller, more frequent water changes would help too.


What are your tap KH/GH and nitrate readings? That would tell us a lot.

 

[Bwhite85]

That sounds so frustrating, sorry. When KH hits zero in 2 days in every tank, I’d suspect your tap water is very soft and has almost no buffer, so the tanks use up whatever little KH they get.


I’d test your tap KH and GH first, and your nitrates too. Nitrates build up fast in a heavily stocked tank, and the process behind them eats KH. Crushed coral is also slow and often not enough by itself.


What I’d try is buffering the new water before it goes in the tank, so you start at a steady KH every time. Smaller, more frequent water changes would help too.


What are your tap KH/GH and nitrate readings? That would tell us a lot.

Thank you! I have tried buffering the water changes which is helping keep the PH very stable, but KH is still dropping quickly. The fish and shrimp seem to be doing ok though.

The tap nitrate is 0, KH ranges from 4 to 6 (I’ve tested it on different days and it varies), GH is 8 to 10. What’s weird is after the water is in the tank, the GH goes way up to around 15-18. Maybe from the coral?

I have two products, a mineralizer for shrimp and an alkaline buffer. The alkaline buffer is better but I read it’s not a good product to use with shrimp and that I should use the mineralizer (salty shrimp) with distilled water. I feel like I’m never going to get the numbers to be in the “ideal” range and just need to keep it stable at this point.