Lower Ph

[Woody]

I have a pair of Apistogramma Makore that breed for me regulary but the eggs are always infertile. I have a feeling because the water is too hard and the Ph value is high, 7.4 and 130 PPM.
I have been performing water changes with 30% R/O water and adding pH down to get the ph down but it keeps bouncing back up.
How long does this take and do I just keep doing what I am doing until eventually the Ph comes down.

Any advice or help would be appreciated

Woody

 

[fishgeek]

increase the r/o % a bit to dilute things
dont use the pH down, just boil some peat to make your own blackwater extract and add small amounts slowly (over days) whilst monitoring the change in pH before any further addition

also it may be worth checking your substrate etc if the hardness is not lessening with your r/o dilution

 

[tjudy]

If you are putting a mixture of RO and tap (30% RO), then you are probably adding carbonate heardness that is buffering the pH up. Use pure RO and add a little aquarium salt and the tannins you are describing. 130 ppm is not all that hard, but a pH of 7.4 indicates an elevated KH.