# Egg Smell Coming from Tank



## CornChip137 (Feb 17, 2021)

This happened before not too long ago when I had sand substrate. I got it to stop by changing to gravel substrate and I replace the biological filter along with a massive water change, and for a while, there was a bacterial bloom. Now, it smells and I'm not sure what it is because I just did a 50% water change a couple of days ago and it's smelling like rotten eggs again. I have a 29-gallon tank with two goldfish, a pearl scale and a ryukin both about two inches. I also have live plants and an aerator. Any ideas of what it could be and how to get rid of the smell?


----------



## The Masked Shadow (Feb 18, 2021)

What you have comes not from the fish, but the substrate. Actually, the poop comes from the fish and stays inside the substrate. Therefore, it creates a sulfur-smelling tank. What substrate do you use? I expect pool sand?


----------



## CornChip137 (Feb 17, 2021)

The Masked Shadow said:


> What you have comes not from the fish, but the substrate. Actually, the poop comes from the fish and stays inside the substrate. Therefore, it creates a sulfur-smelling tank. What substrate do you use? I expect pool sand?


I was using sand but that was the first time it smelled liked eggs, now I have larger gravel and I had just done a 50% water change last Monday. I also have an aerator and I turned that off for a bit and it made the smell less pungent so maybe it's overaerating the tank? is that possible?


----------



## The Masked Shadow (Feb 18, 2021)

Do you have a water vacuum? I believe you can stir it up, then do a large water change. Also, how much percent water changes do u do?


----------



## CornChip137 (Feb 17, 2021)

The Masked Shadow said:


> Do you have a water vacuum? I believe you can stir it up, then do a large water change. Also, how much percent water changes do u do?


I replaced 50% of the water and graveled up the excess food and waste last Monday but what seemed to make it stop was the aerator. Once I turned it off it stopped smelling and now you can hardly smell it at all, does over aerating your water cause it to smell like rotten eggs?


----------



## WildForFish (Aug 5, 2008)

Substrates can smell when waste gets trapped and decays.
Decrease feeding amount.
Gravel vacuum with each water change.
The aerator can bring the foul up due to agitation the water.

What is your filtration?


----------



## CornChip137 (Feb 17, 2021)

WildForFish said:


> Substrates can smell when waste gets trapped and decays.
> Decrease feeding amount.
> Gravel vacuum with each water change.
> The aerator can bring the foul up due to agitation the water.
> ...


----------



## WildForFish (Aug 5, 2008)

What are the waters current parameters? Ammonia, nitrite & nitrate.
What is your water change schedule? Amount & frequency.


----------



## CornChip137 (Feb 17, 2021)

Right now, my ammonia is 0.25 ppm, Nitrite is 0ppm and Nitrate is about 2.5 ppm. I change 50% of the water weekly.


----------



## erndog10 (Feb 26, 2021)

The "egg smell" is Hydrogen Sulfide The result of Nitrates being broken down by *anaerobic bacteria. It's a good thing But yeah It does stink Just clean the gravel really well *


----------



## anewbie (Mar 8, 2021)

As others said it is the substrate. What happens is if the substrate is deep enough and fine it will compact and water will not flow through it causing anaerobic bacteria to form. The solutions are (a) buy some critter that will dig into the substrate (like trumpet snails); (b) use a coarser substrate (caribsea peace river is pretty nice); (c) don't make the substrate quite so deep and generate current over it; (d) don't sweat it.
-
It is not clear if the hydrogen sulfide is 'bad'. The popular opinion is that it is bad for plant roots and fishes (when it escape into the water) but after a lot of 'research' the conclusion is not clear cut... There are positive benefits since the anaerobic bacteria eats nitrate .... so there is that to consider.


----------



## CornChip137 (Feb 17, 2021)

Thanks so much!!


----------

