My 55 Mbuna cichlid tank smells horrid- help!

You mention algae build up on the glass tops...is it algae, or a cyano bacteria? Does it come away in a sheet? Dark green or reddish? Those will have a definite odor to them and it lingers. It's sort of a green rotten smell. You can try removing the glass lids and replacing them with egg crate to stop any jumpers--that will allow for better oxygen exchange, though you'll have some additional water loss to evaporation.
 
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I thought that was odd, too. I use the API freshwater master test kit (liquid). All my co workers have fish tanks (4) and I have used it on all of their tanks as well, helping to get levels within spec.

If I have time Ill test it again today after the WC to see what it shows. The smell is back today and is really bad- very frustrating!
 
Orion Girl- the lids did have a decent amount (one much worse than the other, maybe 6 square inches of solid build up) of forest green colored algae. I used clorox wipes on them and then used rags damp with just water to make sure no residue from the clorox wipes remained.

I think I might leave the lids off over the weekend to see what happens.
 
If you don't have high DOCs (dissolved organic compounds like nitrate, etc) I'll bet OrionGirl is right, cyanobacteria. Prime, too, stinks (like farts, lol)...is your bottle closed tight?

What temp is the tank? Higher temps make all smells worse. I have 1 tank that gets "seasonal" cyano, it gets a bit of full window sun both am & pm at times. I've found a capful of Flourish Excel after each water change really helps in this 75g...but it comes back. Mine cyano is a bright green (it's called blue/green alga). I don't see it in your tank but maybe on the lid. The smell is almost something you can taste especially when you first walk in a closed room.
 
What foods do you feed? Sorry if it's been mentioned, but is any food getting trapped under the top frame of the tank or in the hinge area of the glass tops? Even a tiny bit of flake food in there can wreak badly. Every one of my tanks has glass tops and has lighting that's on from 7-9hrs/day every day and I never get algae on them. I do have to wipe a cloudy film off them (inside and out) every few weeks is all.
 
Something fishy about those test results. You should definitely have some nitrates with that fish load after a week. The tests may not be working correctly, are you using strips or a liquid test kit?.

Yes, those readings are very strange. They cannot be all zeros in a tank with fish.
 
I agree with our resident smarties, cyno can stink and prime as well. I've had fish delivered with heavy doses of prime and it smelt like dead fish but all fish were is perfect health.
 
How deep is your sand bed at the bottom.
If the sand is too deep, you can get anaerobic bacteria that makes the sulfur gas.
Stir up your sand a little bit.. see if bubbles come out.
This is why I do not use sand in my tanks.. or if I do use sand, it is only maybe 2 grains deep.
You can stir up your sand every time you do a water change to help things (move the rocks and stir up that sand too) or switch to gravel.. Or a thinner layer will help.

Note, this is a guess.. this happened to me.
 
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