Air stone in a reef

[Calireefer92]

Hey reefer question on air stones in a reef tank. Trying to get my ph up and people say you get get ph up using an air stone. I have a 200 gallon tank the sump is a 40 gallon breeder what size air stone should I use?

 

[DanyL]

You need to take into account that this only works if the room’s CO2 levels are lower than your tank’s, otherwise it’ll do the exact opposite of what you’re trying to achieve.

Before proceeding with adding airstones I would do a simple test to make sure additional agitation does in fact increases your PH and won’t lower it. This can be done by simply directing your pumps at the water level and waiting an hour or so to compare the results. This alone btw can achieve quite good results for some, without the need for additional aeration.

If this isn’t enough, you can also setup the air pump or the Venturi air intake of your skimmer to pull air from outside - this is usually one of the best and cheapest solutions for a low PH, although not everyone is able to set it up.

As for what air stone to use - I think that multiple (2-4) 4-5cm air stones will do and even a better solution would be to add an additional skimmer with its drain open.

 

[taricha]

A much more commonly effective modification to raise pH is to change the skimmer setup so it can pull air from outside.
This operates using the same principle as mentioned above. It only works if your outside air CO2 is significantly less than the CO2 of the indoor air that the skimmer would be pulling otherwise.
For a lot of people this is true and worth doing, but not for everyone.