Sulfur smell

[johnwe]

I have a new 90 gal tank I have set up temporarily on my deck. I placed 10 tetras in it.

The tank has a 40 gallon sump, probably with about 29 gallons in it, filter media and a heater.

The tank has had fish in it a week. I added safe start when I added the fish as well as a large sponge from my cycled discuss tank.

This morning the fish were hanging out in a lower corner and somewhat inactive. I water test revealed ammonia was at least 0.25. pH was 6 or lower (test showed yellow)

I did a 25% water change this morning after seeing the fish were less active, soon discovered one was dead. I used some API water conditioner to eliminate chlorine, I was a little concerned that I did not use enough and have gotten into the habit of using prime. Therefore I opened the prime I had just received in the mail and dumped in about a 1/2 shot full

Late this afternoon I got home to the tank with a bad sulfur smell. I few dead fish and a few hanging in there looking white around the edges.

Did another test before changing 50%. pH still 6 or lower ammonia maybe .25, no nitrites.

Any idea what the sulfur smell is from?

Could mixing API and prime conditioners cause an issue?

I know prime has some odor, but I can smell the tank from a few feet away.

[tcyiu]

A couple of questions and observations:

- You said the tank is on the deck. How cold does it get at night in Connecticut? Is the water heated? Cold temperatures will lower fish metabolism and they'll just huddle in the corner. They shouldn't perish right away because of low temp, but they will NOT be very comfortable.

- Has the filter been cycled prior to adding fish? Testing positive for ammonia could be an indication that the filter is not cycled and the fish are being poisoned. Or the test kit may be fooled by the breakdown of chloramine. What test kit are you using?

- as for Prime, what is a 1/2 shot? Is the amount consistent with what the bottle recommends for the volume of water in your tank? Or are you just overdosing to "be on the safe side."

- Most de-chlorinators use some form of sulphur compound to react with chlorine/chloramine. Therefore, unless in crystal form, de-chlorinators will have some slight rotten egg smell. But not so much that you can smell from far away. If the smell is intense, something has gone wrong with the nitrogen cycle in your filter. Somehow, hydrogen sulphide (toxic) is being produced and this could also be killing your fish.

If it were me, I would do a 100% water change with de-chlorinated water (follow the directions on the bottle and don't "wing" it). Add a little salt to the water to take the edge off of nitrite poisoning.

This should buy your fish a little time while you figure out what went wrong. Keep up the massive WC until you find the root cause.

HTH

Tim

[johnwe]

If the smell is intense, something has gone wrong with the nitrogen cycle in your filter. Somehow, hydrogen sulphide (toxic) is being produced and this could also be killing your fish.


I think this must be it. I am used to the slight odor of prime. This is pretty intense.

The tank was not cycled first, I used Safe Start, a bottle listed for 75 gallons, maybe that had gone bad and caused the bad cycle.??

I assumed a cycled sponge from my other tank would be enough to get a cycle started for 11 tetras in 120+ gallons.

The tank is heated, it's been warm here lately. The temp does not go too far below 80, stays close to 83 most of the time. The fish began swimming again directly (even during) the first 25% WC. The temp was 83 at the time.

I have a sump question. I have a large amount of floss below the pvp pipe that drops out of the upper tank. The pvc is submerged...could that being causing an issue?

Yes I added more Prime than necessary to be on the safe side.

I am using an API water test kit

What could cause a bio filter to "go bad"?

[boxters]

the smell you are refering to is sulphur dioxide. It is caused when bacteria become anerobic and is highly toxic to fish. I would check your sump and media

[johnwe]

Thanks for everyone help here.

I'd like to figure out what caused this. Any ideas?

Could it be that some of the nitrogren cycle activity (sorry for my lack of chem language) has been trapped under the filter floss? ie the filter floss trapped a pocket with little air? Similar to what I have read that could happen with aquarium substrate being too deep and lacking aeration?

[boxters]

yes for sure. It also happens if your pump switches off for a while. all the water in the tubing lacks oxygen and goes anerobic. Also if there is not enough water flow for the media it will turn anerobic. check water flow, and make sure pump is working properly also no air pockets like you mentioned

[johnwe]

Sorry this is going to sound naive.

When doing water changes with a sump, do people normally shut off the pump during the WC?

That's what I did. Could ~10 minutes without flow through the sump/return-plumbing have causing this?

fyi bare bottom tanks involved here

[tcyiu]

The problem I have with this whole scenario is that anaerobic bacteria take a long time to grow. Boxter may very well be right. It's just that the whole thing doesn't smell right. Sorry for the pun.

(BTW, if what you're smelling is like rotten eggs, the chemical is Hydrogen Sulphide. I made the stuff to create stink bombs as a boy. As a nerdy boy. So I did a bunch of book learning on the stuff.) :p

Is there any dead body trapped in the sump? When my homemade grill fell off, a bunch of cardinals got sucked up and ended up in my sump. Do a nose count and see if all the tetras are still there.

Tim

[johnwe]

all dead fish were removed, I did the count already.

The first dead one might have been there for up to 8 hours, I can't know for sure, but we're talking a small lemon tetra about 1.25 inches caught against the teeth of the overflow. I don't think this would cause such a big issue in this amount of time in a tank this large.

In addition the sump does stink too

I think this might be something with the sump or the plumbing.

[Jhhnn]

Sorry this is going to sound naive.

When doing water changes with a sump, do people normally shut off the pump during the WC?

That's what I did. Could ~10 minutes without flow through the sump/return-plumbing have causing this?

fyi bare bottom tanks involved here

I shut off the pump on my one trickle filter sump system during water changes. It'd have to stay off for a very long time before anaerobic bacteria activity became significant. A very long time, probably days.

[boxters]

it would have to be off for at least 24 hours. But what you are smelling is definately hydrogen sulphide. And its toxic to fish. You need to find the cause.

[tcyiu]

I shut off the pump on my one trickle filter sump system during water changes. It'd have to stay off for a very long time before anaerobic bacteria activity became significant. A very long time, probably days.

I agree with Jhhnn. It would have to be a very long time. I have left canisters off for two days with no ill effect. I have also left a Magnum 350 used as a DE filter for two weeks. Whew!!! Nasty.

So the answer is somewhere between 2 days and 2 weeks.

You're right that a small lemon tetra is not going to stink up anything.

I really don't know what to say.

One more idea. In the sump, are there pockets where water does not readily flow (or is gummed up with filth), and which is very dark? Over the course of the week of running your tank, anaerobic bacteria might have taken up residence there.

Tim

[nc0gnet0]

You should be able to keep a dozen tetras in a 100+ (including sump) without issues, seeing how you put a cycled sponge in the tank. Is all the media in the sump new? If so anerobic bacteria is not an issue, and you would need it to be off at least a day for that to happen. But while were on the subject, loose the floss in the sump and get a few filter socks, much better IMHO.

I am going to guess that the sulfur your smelling is from the water conditioner and dechlor. I don't hold much faith in the bacteria in a bottle approach to cycling a tank, and I would give up on doing that. Your cycled sponge should do the trick.

Tetra's are notoirious for die-offs when just purchased from your LFS. The are a big seller with a high turnover, and often the ones you get have just newly arrived to the LFS and have already undergone quite a bit of stress.

[tcyiu]

Tetra's are notoirious for die-offs when just purchased from your LFS.

Man! I completely overlooked that. Totally AGREE with nc0gnet0. The tetra death may have been a red herring.

But the sulphur smell is still too weird. Maybe the OP has a super sensitive nose. I had a bottle of sodium thiosulfite solution turn completely yellow. Yet upon opening the bottle, the smell of H2S was strong, but not strong enough to smell from a few feet away.

Tim

[nc0gnet0]

The sulfur smell is someting to watch for sure, but the smell of sulfur doesn't automatically mean the presence of hydrogen sulfide. I know safe has a very strong sulfur smell, I am not so sure about the product the OP is using.

[roundfishross]

it could just be the smell of his tap water.
i have seen tap that smells of rotten eggs

[johnwe]

Yesterday I did a 25% and later 50% WC. When doing the 2nd WC I moved the floss around in the sump to be sure there were no "pockets" with poor flow. At that time the odor was pretty bad.

Today the odor is nearly gone.

I have a sense that this was caused by bad flow in parts of the floss in the sump.

I am going to get a sock and look into other media in the sump. Right now it's floss and plastic army men plus the seeding sponge.

[nc0gnet0]

Invest in some socks and matala. David Rose, one of our sponsors sells matala on his sight.

[tcyiu]

Yesterday I did a 25% and later 50% WC. When doing the 2nd WC I moved the floss around in the sump to be sure there were no "pockets" with poor flow. At that time the odor was pretty bad.

Today the odor is nearly gone.

I have a sense that this was caused by bad flow in parts of the floss in the sump.

I am going to get a sock and look into other media in the sump. Right now it's floss and plastic army men plus the seeding sponge.

Good deal.

BTW, be careful when you do that. The unintentional release of more toxins could be harmful. If it were me, I would stop the filter, shake everything down, discard all the water, rinse it with tank water. Turn it back on AND do a massive WC. Just to be safe.

Also, I would not use floss in a a wetdry. Use something else for mechanical filtration. Floss is way too dense for what is essentially a gravity operated contraption. It works good in a canister where water is pulled through. IN a wet/dry, the stuff mats down, and clogs.

You're kidding about the army men, right?

nc0gnet0, You're right. The sulphur smell does not automatically equate H2S.

Tim

[discusdave]

Prime smells like sulfur, as sodium thiosulfate is the primary ingredient in any dechlorinator.