Have to get humidity down: glass tops or canopy?
 

I am getting mold in my finished basement and need to quickly get my humidity down.
My 180 evaporates around 5 gallons every three days.
I know a glass top would help , but would a canopy(without glass top) make a difference?

a canopy will help also ,if its sealed or tight if it gaps it wont do much good, if your not renting you can consider installing a airexchanger or simply buy a dehumidifier:)

I bought a dehumidifier off Kijiji for $150. It keeps humidity around 35%. Before the dehumidifier the house would usually be around 50%, but sometimes up to 65%. My 90 gallon tank evaporates about 15 gallons per week. Before the dehumidifer it evaporated about 10 gallons per week. Understandably, lower humidity in the house does make the tank evaporate more.

Pertaining to the original question though, glass tops work better than a canopy (unless canopy is well sealed), and have the benefits of keeping temperature lower since you can cover the tank with glass, and still have fans to blow the heat from the halides away. However, I wouldn't suggest you seal the top of your tank in any way if you don't have a sump, and especially if you don't use a skimmer.

If you do seal up your tank, keep an eye on your pH with a calibrated digital pH meter as it may fall due to CO2 buildup if the tank doesn't get enough fresh air. Check before sealing it up several times during several days, then do the same thing after. Record the time and the reading, and compare readings at the same time as pH will fluctuate during the day, but should follow a daily routine.

humidity
 

having a bathroom fan on will help or a fan venting to the outside-as for the mold-wash your walls with deluted bleach to kill the mold and it might be an idea to paint with a kitchen bathroom paint-or tint some kiltz

I think if water is condensing on/in the walls, then you do not have adequate insulation in those walls. As well, just for information, I have found a lot of places where the homeowner has done work him/herself and has not put the vapour barrier on the proper side. The vapour barrier always goes on the inside, the warm side. (in the winter.)

I guess the one downfall of glass tops is that you don't get the full benefit of your lights?

GLASS
 

Another downfall of a glass top is trapped heat. I would not recommend it.

Get a dehumidifier. That's also an issue I am having and seems that others have been successful going that route.

If you own your home and plan on having that tank for a while then I would suggest looking into and HRV.

The glass top will cut down evaporation but will also need to be cleaned very often. It'll become a chore that you will dread. The glass top will also trap other harmful gasses that the tank exhausts. I would never recommend a glass top.

Whats an HRV???? I am a new home owner.... maybe I should have one?

http://www.oee.nrcan.gc.ca/residenti...-hrv-works.cfm

In short, it takes stale air from inside your house and vents it outside. It takes fresh air from the outside and brings it inside. The warm air that is vented outside is used to heat up the fresh air coming in so that you don't lose too much heat. The one side effect that we are interested in here is that it will take humid air out thus dehumidifying your home. Highly recommend for new homes or homes that have upgraded their windows to higher efficiency windows because those houses are like cocoons.

We just installed in our house a couple of weeks ago. Before we were were battling 55 to 60% humidity and had to open windows and turn on all the bathroom fans all day long.. brutal! Now our house runs at a comfortable 40%