What's better for water stability?

[MizTanks]

Please explain reasons.

What's better for water quality and stability? Open top tank or closed?

[taziam10797]

In my opinion open top is best for water. It allows the flow of oxygen into the water. Good for water, bad for jumping fish.

[XSiVE]

IMO open top for better gas exchange. If you close the top of the tank, the pH is going to be lower due to co2 buildup.

[bigbill]

Originally Posted by XSiVE

IMO open top for better gas exchange. If you close the top of the tank, the pH is going to be lower due to co2 buildup.

+ 1 on this

[adalius]

Mesh top is my favorite.

[MizTanks]

Thanks guys. Explains why my ph has been so low, 7.6
I'll be propping the hood open from now on.

[Manoj's Reef]

+1 on open. Make sure you compensate for lost water.

[XSiVE]

Originally Posted by Manoj's Reef

+1 on open. Make sure you compensate for lost water.

oh yeah, forgot to mention that you will definitely have more evaporation, so depending on how often you top off, you may have a little instability in salinity level.. but if you're asking about this for your 26g setup, theres probably enough water volume to not have to be at all concerned.