There are several ways to reduce PH.
1). Driftwood, barley, leaf litter added to your tank leach tannic acid into the water lowering ph slowly. The effect is gradual and is effected by your tanks KH
2). If your tank is planted adding a CO2
system will lower your ph. Be careful with this method too much CO2
and you will poison your fish.
3). Tanks lower in ph as they age. Effect is very gradual.
4). If you you are diligent with finding the exact ph of your WC
water each time. Additives that effect KH
can lower your ph quicker. But test on your tap water in a predetermined amount. Example 5 gallons you may use 1/4 teaspoon of chosen additive to meet the now lower PH of the tank. If you do this each time the water you add will be same ph as the tank.
With Bolivian Rams stability is more important than matching their exact wild environment. They will live perfectly fine at around 7
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