Hey guys so real quick background information. I work at a nature center in Weslaco, TX, and we just installed two tanks (fresh & saltwater). Now the other park technician took lead in the tank setup because he used to work at a pet store and he has experience with saltwater tanks. We basically made everything ourselves except for some parts we ordered online (protein skimmer, pump, etc.) and it seems to be working fine, but we keep having to refill the tank with water, i'm pretty sure its due to the loss of water via humidity, I just wanted to know if we should buy some plexiglass and just cover the sump.