glass lid question


New member
from reading many of the post and pics of people tanks on here it doesn't seem that many use a glass lid on top. why is this?


The main reason many leave the glass off is for gas exchange with the air to remove excess carbon dioxide.

Good article from Randy here:

The other reason is with bright lighting you will get a lot of heat retention. High water temp!!

Some want the tank to evaporate at a faster rate to allow additional top-off of RO/DI water combined with calcium and alkalinity additives. I’m in a little bit of a different situation here in the desert. I have left a portion of the tank covered with glass to prevent or slow down a lot of evaporation (it’s pretty dry here!) and prevent too much top-off from my Kalk reactor.