PH Level - How to lower?

[hfabs]

Hihi

Can I kindly seek any advice on lowering the PH level. I do a 10% WC weekly but it is still high (current volume is 150 gallons (4.5 x 2 x 2.5ft tank) with fishes and corals. Currently, my PH is ard 8.6-8.7. Please help : )

Many thanks

[comycus]

How are your lifestock doing? Stability is more important than lowering your ph, if your tank inhabitants are all doing well.

Has your test kit expired? or is your ph meter properly calibrated? You may be worried for nothing if the values you have been getting are wrong.

Otherwise, you may want to read this excellent article to understand reasons for high ph and lower it GRADUALLY

http://www.reefkeeping.com/issues/2005-03/rhf/

[hfabs]

Thanks : )