What's with the trend for 'Open' tanks?

[GaryE]

Emergent plants tanks are great, but I still add glass around them as much as I can. The lidless tank idea is aesthetic. It isn't practical.

If you can find fish that never jump, okay. If you have no humidity, home heating or similar issues, fine. Otherside, it becomes a calculation I don't like - that fish will die as a result of the set up.

I have open tanks, since my set up has been in a garage. In a house? No. Wouldn't do it. I have killies - great jumpers - so in those tanks I'd be kind of dim to leave them open on purpose (I have slipped up when feeding or doing water changes). Open tanks are only for emergent plant tanks, and I leave a gap unfilled.

I suspect if you keep shrimp, they might be safer.

 

[WhistlingBadger]

I suspect if you keep shrimp, they might be safer.

I've had amano shrimp go for a walk, from a covered tank no less. Found their way out through the filter tube openings. It did tip me off to some water quality issues.

 

[Herbibore]

A question about tightly covered hi-tech freshwater tanks: does C02 collect in the space between the water and enclosed top to levels that might harm a fish like a betta, that occasionally breathes at the surface?

Not too worried about that, but I have thought about it.

 

[GaryE]

Bettas can drown - that surface breathing isn't occasional. But I'm too low tech to answer.

 

[Byron]

You specifically mention high-tech planted tanks, and I cannot say...but what you are asking about would never occur in a low-tech or natural planted tank unless the tank cover provided no openings at all. And this should never be the case, as the oxygen/CO2 gaseous exchange at the surface is important to the extent of being crucial. I have had CO2 levels in the water of well-planted tanks build during the night to the degree that the fish (Corydoras especially) had a very noticeable rate increase in respiration in the early morning. I resolved this by increasing the surface disturbance (day and night). If the tank cover were actually sealed to the tank, I would assume the CO2 would build up and oxygen become depleted.

 

[itiwhetu]

You specifically mention high-tech planted tanks, and I cannot say...but what you are asking about would never occur in a low-tech or natural planted tank unless the tank cover provided no openings at all. And this should never be the case, as the oxygen/CO2 gaseous exchange at the surface is important to the extent of being crucial. I have had CO2 levels in the water of well-planted tanks build during the night to the degree that the fish (Corydoras especially) had a very noticeable rate increase in respiration in the early morning. I resolved this by increasing the surface disturbance (day and night). If the tank cover were actually sealed to the tank, I would assume the CO2 would build up and oxygen become depleted.

I have always used air curtains to disturb the surface tension of a tank. What do you do?

 

[Byron]

I don't know what "air curtains" are. I just ensure the filter return is causing rippling of the surface in the area of the return, not across the entire surface as I have fish that do not like this and floating plants. It doesn't take much.