I had a discussion with a friend on marine. He has a high of 8.7 and he added that he is trying to reduce it to 8.4. Any hints?

Hi niko001,

The first thing he should check before I can suggest you technics for lowering PH is to check the PH of the freshwater he is using, and also when he mix it with the salt to achieve the correct salanity what PH reading is he having.

If he is using tapwater, it is normal to have high PH readings, that's why it is suggested to use RO water or RO/DI water.

Thanks Maltese. So tap water PH (if he is using tap water), any changes of PH after salinity.

What if he is using RO water?

Normally tapwater has high PH, so when mixed with the salt we buy from LFS's it gives you higher reading then needed.(like you said, 8.7 is on the very high side and could stress your fish in a minute and lead them to death)

The salt we buy it's best to be mixed with acid or neutral PH reading and not higher, so normally it will gives you PH reading between 8.1 - 8.4 but also depends the brand you are using.

Always before making water changes with saltwater aquariums, you need to check the Temperature, SG and the PH readings. If no, you will never have a stable system and rapid changes especially in marine could be fatal.