Adding HCl to top up water

earthbound

If it drops below 7 then adding water with a pH that is higher than 7 is better than adding water at 7.

Think of it this way, forget the bit about whether it's top up water or water already in your system, think of it as a whole.. You are adding acid to your system, which is going to drop your pH even more..

nih

My tap water also has a high ph and is quite hard. My first system had a ph around 7.8 - 8.0 for about a year and has now just started to drop by itself.
I did add HCl to my water for a while over summer to try and bring it down a bit because I was worried about the increased toxicity of ammonia at the higher temperatures when i had quite a few large barra putting a fair bit of load on the system.

Jackfrost

earthbound wrote:

If it drops below 7 then adding water with a pH that is higher than 7 is better than adding water at 7.

Think of it this way, forget the bit about whether it's top up water or water already in your system, think of it as a whole.. You are adding acid to your system, which is going to drop your pH even more..

Ok so considering that Perth rainwater is 7.0 or lower then your advice to those using rainwater would be to increase the pH before adding it to their system?

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