Ph problem

[Jonesy]

Hi everyone
What would cause the ph to go up in my tank?
Every time i do a water change i make sure the water im putting in my tank is at 7.5 but when i test the water a week later it gone upto 8.5.

 

[HAVAMAL]

Do you use an airstone?

 

[Jonesy]

Ye i have got 2 one small round one and one long one

 

[HAVAMAL]

There's where your problem lies, airstones raise water hardness which in return raises ph if you like the airstones then add a piece of driftwood to the tank it will help soften the water and it will lower your ph.

 

[Jonesy]

There is already 3 pieces of drift wood in the tank and the water hardness is quit low i think last time i tested the kh was 6 and dont you have to have an air stone to get oxygen into the water

 

[HAVAMAL]

What kind of setup do you have?

 

[Jonesy]

I have got a 300ltr tank with a 4 tray filter system and a 900ltr per hour powerhead feeding the filters, 2 air stones, 3 pieces of drift wood 60kilos of 1-2 mil gravel and about 20 live plants

 

[bruinsbro1997]

Do you have any rocks like limestone???

 

[Jonesy]

No rocks just a ornamental submerine