trenac· Premium Member
I have 3 of my tanks as open top tanks, I perfer these over the closed top tanks. The biggest disadvantages I see are evaporation and fish suicide. I top off the water once a week, this is not that big of deal if you run canister filters. If you run HOB filters then you really need to keep on top of topping off the water due to surface aggitation. I think in a year and a half of keeping open top tanks I've had 3 fish suicides & 1 shrimp suicide. This was most likely from the fish getting chased by another fish or bad judgement by the fish (LOL). The advantages is ease of maintaining the tank, ease of feeding the fish, watching the plants grow beyond the surface of the water and being able to see floating plants from above.