[coreno]

I am new to aquarium care; started mine in October. It is a 40 gallon tank.

Starting this past weekend, it's developed a sulfur smell, after I had already done a partial water change.

I did some quick research, and learned the smell is probably as a result of hydrogen sulfide. What causes this? A breakdown of organic matter by bacteria.

I started using Algaefix by API this weekend too, after I had done a partial water change. So I'm thinking that the Algefix is causing the algae to breakdown and smell. I plan to do another water change after work today and change the ammo-carb in my filter.

I quickly tested my tank for ammonia during my lunchbreak and it looked good.

My question to everyone here is do my deductions sound reasonable, or am I about to nuke all my fish? Any other steps I can take to remove this smell?

 

[Geomancer]

Hello and welcome!

Lets get some background info first. What substrate do you have?

How often do you do water changes, and how much?

I would avoid using a chemical to kill algae, the effects on the fish are questionable at best. Algae is caused by too many nutrients in the water, and too much light. All tanks with have some algae though, and that's perfectly fine, healthy, and natural. Best ways to control algae is keeping the tank clean (reduce nutrients) and reduce the amount of time the tank gets light (say 8 hours a day). Direct sunlight is a big no no.

When you tested ammonia, what was the actual reading? "looked good" depends on the person

 

[coreno]

Hello and welcome!

Lets get some background info first. What substrate do you have?

How often do you do water changes, and how much?

I would avoid using a chemical to kill algae, the effects on the fish are questionable at best. Algae is caused by too many nutrients in the water, and too much light. All tanks with have some algae though, and that's perfectly fine, healthy, and natural. Best ways to control algae is keeping the tank clean (reduce nutrients) and reduce the amount of time the tank gets light (say 8 hours a day). Direct sunlight is a big no no.

When you tested ammonia, what was the actual reading? "looked good" depends on the person

I suck at comparing colors, but as best as I could tell, ammonia was at 0. I do know enough that any level of ammonia is bad; but in the life my tank, I have not tested at any discernible level of ammonia.

I'm kind of inconsistent with my water changes, but in general try I do about 25-33% every other week, but I've gone 3-4 weeks without a water change in the past.

I have a gravel substrate.

Too much light might be a problem; it doesn't get direct sun rays, but it is by a large window where it gets direct daylight.

 

[JDM]

I would think it unlikely that you have hydrogen sulfide, even less so with gravel unless it was very deep. This is usually attributed to a sand substrate that is 3" or deeper as the process only occurs in substrate where no oxygen can penetrate.

Adding chemicals can do any number of things and I wouldn't recommend them unless absolutely necessary. I don't know if your smell could be from that or not but it is possible.

If you really wated to prove or disprove the H2O possibility you could stir up the gravel or maybe just poke it here and there, if there are bubbles that pop up and all of a sudden it smells like sulfur, then you may have some. More than likely they would just be CO2 though and produce no smell... regular decaying smells aside depending on how clean your gravel is.

Jeff.

 

[coreno]

I would think it unlikely that you have hydrogen sulfide, even less so with gravel unless it was very deep. This is usually attributed to a sand substrate that is 3" or deeper as the process only occurs in substrate where no oxygen can penetrate.

Adding chemicals can do any number of things and I wouldn't recommend them unless absolutely necessary. I don't know if your smell could be from that or not but it is possible.

If you really wated to prove or disprove the H2O possibility you could stir up the gravel or maybe just poke it here and there, if there are bubbles that pop up and all of a sudden it smells like sulfur, then you may have some. More than likely they would just be CO2 though and produce no smell... regular decaying smells aside depending on how clean your gravel is.

Jeff.

My gravel isn't very deep. Didn't notice any bubbles coming up from it though, but if there were, I don't think I'd notice any extra smell... the smell took over most of my apartment. I changed the ammo-carb in my filter and did another water change.

We'll see where that gets me.

 

[Byron]

I concur fully with the advice to not use algaecide. If you have live plants, they will help control algae (along with light and nutrient balances) and the algaecide will harm some plants outright. Without live plants, algae is actually very beneficial, since it performs some of the good that live plants offer, namely taking up nutrients and producing oxygen. This algaecide may be the source of the smell; I've never used these, so have no experience.

Water changes should be weekly at the least; the volume depends, but you really can't do too much. I do half my tank volume (on all 7 tanks) every week. If you have no plants, then use a water changing apparatus to vacuum into the gravel at each water change. With live plants this is much less necessary because the breakdown of organics provides nutrients for the plants; without plants, these nutrients are getting into the water and nitrate often rises and pH may lower. BTW, have you tested for nitrate and/or pH?

Byron.

 

[coreno]

Ok, I'll stop using the algeacide. I started using that because it's getting on my fake plants and it's very hard to get off the fake plants.

Hopefully it was just that creating the stink though.

 

[JDM]

I don't think you'll have much choice with fake plants but to pull them out and clean them every once in a while.

Jeff.

 

[MoneyMitch]

I would think it unlikely that you have hydrogen sulfide, even less so with gravel unless it was very deep. This is usually attributed to a sand substrate that is 3" or deeper as the process only occurs in substrate where no oxygen can penetrate.

Adding chemicals can do any number of things and I wouldn't recommend them unless absolutely necessary. I don't know if your smell could be from that or not but it is possible.

If you really wated to prove or disprove the H2O possibility you could stir up the gravel or maybe just poke it here and there, if there are bubbles that pop up and all of a sudden it smells like sulfur, then you may have some. More than likely they would just be CO2 though and produce no smell... regular decaying smells aside depending on how clean your gravel is.

Jeff.

just supports the fact that hydrogen sulfide is harmless in a aquarium since once it is released form the substrate and comes into contact with a oxygenated water colum it is almost instantaneously converted to sulfer which is harmless.

 

[JDM]

just supports the fact that hydrogen sulfide is harmless in a aquarium since once it is released form the substrate and comes into contact with a oxygenated water colum it is almost instantaneously converted to sulfer which is harmless.

First a correction. When I wrote H2S I think the iPad auto corrected it to H2O. I didn't catch it.

Second, It doesn't harmlessly oxidize in water, the dissolved gas becomes hydrosulfuric acid, but I doubt that it is the scourge that it is supposed. Never having dealt with it, I don't know although I expect that the volume of this acid in a tank is small enough that the dilution is adequate to avoid any deadly exposure.

Jeff

 

[coreno]

Well it's good to know that if the odor was H2S, it probably wasn't all that harmful (though apparently debatable).

So far since the water change, at the very least it's not as strong; but it's only been a few hours.

Thanks everyone for the help so far


P.S. I added an aquarium to my profile, but now I don't know how to edit it

 

[Byron]

P.S. I added an aquarium to my profile, but now I don't know how to edit it

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