low ph

Question
Richard
my 135 gallon tank i am fighting low ph hoovering at 6.0
I have been changing 25% of the water every week for 6 weeks and can not get the ph to stabilize at 7.0. it is a fresh water tank
and is very clean abd very clear nitites are o nitrates are at 0 amonia is at o.
the water used for replenishing is 8.o
ihave my fish guy at the pet store stimped he has so he says 20 yrs experience but something in the minerals is off arfter alot of reading .not interested in adding crushed corals .
Ineed your help
chris

Answer
Hi Chris

You didn't tell me what type of fish you have in your tank. It really doesn't make that big of a difference unless you have African Cichlids.

Most freshwater tropical fish will adapt and do fine in a pH of 6.0 - 8.0 as long as it is stable. It is much more important to have a stable pH, than trying to buffer it. Buffering the pH will cause serious pH swings which will stress and kill your fish. Also, chemicals that buffer the pH are only temporary, they won't keep the pH at a set value between water changes.

First thing to do is make sure there is nothing in the tank lowering the pH such as driftwood. Next make sure there are no additives in your filter lowering the pH. Also, when you say the replenishing water is 8.0...is that bottled water or out of the tap? The best way to test your tap water is to fill a 1 or 2 gallon bucket with tap water, add your water conditioner, AquaSafe or StressCoat, let it sit for 24 hours then test it again.

In an African Cichlid tank, even African Cichlids will do better in a lower, stable pH than a buffered pH. Africans are more sensitive to pH swings than other freshwater fish. I use African Cichlid sand in my African Cichlid tanks and it keeps the pH at 8.2.

If you insist on raising the pH, to keep it constant, you could try the African Cichlid sand even in a freshwater community tank, or limestone rock will also raise the pH. But remember to add these gradually to prevent a sudden pH spike.

Again, I must specify not to add pH buffering chemicals to your tank, they are nothing but an avenue for disaster.

I hope this is helpful to you, good luck!

Richard