Top on aquarium

aduvall

aduvall

Member
I have a lid on my aquarium. Only have about a 1 foot long, 2 inch space in the back half. Is this large enough for "gas exchange" or should I switch to some sort of screen top?
 
flower

flower

Well-Known Member
Saltwater tanks should NOT have a lid on them. Most folks get a canopy to put over the top, it allows space between the light and water, plus it makes the tank look finished and more attractive. Folks also use egg-crate material to prevent fish from jumping. Egg-crate is found in the lighting section of the hardware store, it's actually made as a light defuser....it looks like egg crate so we call it that.
 
bang guy

bang guy

Moderator
aduvall said:
I have a lid on my aquarium. Only have about a 1 foot long, 2 inch space in the back half. Is this large enough for "gas exchange" or should I switch to some sort of screen top?
Click to expand...
If you can find a way to get airflow across the water surface then the gap you have is adequate.
 
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aduvall

aduvall

Member
So not just aurface water movement but like a fan?

What is eggcrate? And where would I find it? (More detail than lighting section)
 
honu808

honu808

Member
Has to be a gap between any lid type and surface of water for gas exchange.
Eggcrate real name is light diffuser and can be found in same aisle at Lowes as false ceiling tiles. It is plastic maybe 3/8" squares and usually like 3'x4' pieces for about $12. Hope that helps.
 
bang guy

bang guy

Moderator
aduvall said:
So not just aurface water movement but like a fan?

What is eggcrate? And where would I find it? (More detail than lighting section)
Click to expand...
It has to have airflow that's why most people don't use lids. If the water is circulating under stale air it doesn't help gas exchange because the air above the water will be loaded with CO2. You need some way to blow the CO2 out from under the lid. It's not going to take much airflow but it needs some level of air movement that you can't get naturally with a lid in place.
 
aduvall

aduvall

Member
What if I gap the length of the tank in the back 2 inches? Will that let in more O2? Especially if my return pump splashes in that area?
 
aduvall

aduvall

Member
There is a vent above it... Not sure if that's enough. How big of a gap would I need without air movement?
 
aduvall

aduvall

Member
I have a hoevans wrasse and a starry blenny. Both have been known to jump...

Do you think it's safe without?
 
flower

flower

Well-Known Member
aduvall said:
I have a hoevans wrasse and a starry blenny. Both have been known to jump...

Do you think it's safe without?
Click to expand...
I put a mesh on top of my tank to keep my fairy wrasse from jumping...the critter waited until I went to feed the fish, and pulled JUST A CORNER open, it leaped to it's death (I heard a little water sound but didn't know it had jumped out)...I missed the fish and went looking for it...found it behind the 90g tank in the center of the back behind the sump, where I couldn't reach it even if I had known it had jumped. I reached it with a long pincher device. I think they deliberately commit sushi. I had a firefish manage to leap to it's death through the egg crate, he timed his suicide after I went to bed...then aimed just right to fit through the little opening of the egg crate. I decided to no longer purchase long bodied fish, which are the jumpers.

So to answer your question to is it safe without a top...no. However even that space in the back of your lid is enough for them to kill themselves....Then add in the gas exchange problem, it's waste to have.
 
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jay0705

jay0705

Well-Known Member
I have a top on my tank, I leave it gaped in the back to allow gas exchange. About an inch the length of the tank. Then its open where my hob filter hangs. About 2 inches on either side. My mcoskers wrasse found that 2" opening!! Luckily he was found, alive still going strong a yr later, but yes wrasse are little jumping bastards lol. My fire fish, never jump lol
 
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