rotten egg smell

[runningrandy04]

Hey guys,
I'm starting to get a rotten egg smell coming off of my tank and don't know what to do. The tank has been cycling for almost 3 weeks and hasn't smelled like this before. I've been doing a 10% water change twice a week. I changed the filter pads 2 weeks ago. Added 11 red legged hermit crabs and started running phosguard 2 weeks ago to keep algae under control. Found 4 dead hermit crabs 4 days ago (hermits hiding in rock fighting for shells). Pulled out all the dead bodies and got 3 peppermint shrimp on sat. to eat remaining parts and eat apistasias.

Tank readings before i got shrimp.
Ammonia 0ppm
Nitrite 0ppm
Nitrate 7ppm

Tank readings now:
Ammonia .25ppm
Nitrite .075ppm
Nitrate 5ppm
PH 8.0, Temp 75, Calculated Toxic Ammonia .0125ppm

I'm lowing the Temp to 73 to lower the Toxic Ammonia. What else can I do? I counted all but 1 crab this afternoon and the shrimp are still alive.

 

[poolshark181]

your cycle isnt complete. the rotten egg smell sounds like it might be from uncured rock, but that is odd that you havent smelled it up until now. water changes are usually not done until after the cycle completes, and may even prolong the cycle. i did nothing to my tank while it was cycling and it took about 4 weeks.

 

[runningrandy04]

yea...i started out with 25lbs cured live rock and 20lbs live sand, and have been doing water changes to prolong the cycle and save as much life in the rock as possible. Also, i only did the water changes right before and a couple days after i added new creatures. still dont know why i would get the egg smell now

 

[Piggy]

The smell is hydrogen sulfide. It occurs from decomposition of dead animal with lack of oxygen. What are you using for water movement? Is it breaking the water surface?

 

[runningrandy04]

i have 2 penguin 145gph powerheads at the top breaking the surface and i have the biowheel 350. its a 20L tank

 

[Piggy]

Seeing your using LR and sand. I wouldn't think it would be that. Could of been coming from the dead snails.

 

[runningrandy04]

I had a crab digging to the bottom trying and get under a rock. That might have stirred up the low oxygen bacteria/decay but i didn't think that could happen within 3 weeks.

 

[Piggy]

I wouldn't think it's comming from the sandbed. Is it getting worse or does it seem to be going away? Was your cured rock fully cured? Where did you get it? All I can come up with is die off.

 

[Altohombre]

you shouldn't have put the hermits and especially an expensive shrimp in the tank until a week or so after your tank is cycled.

 

[runningrandy04]

It seems to be going away. I got it from a saltwater only fish store, and the tank they had it in didnt smell at all so I'm pretty sure it was fully cured. I'm guessing the shrimp are breaking up stuff and its decomposing faster. thats the only reason i can think of. thanks a ton for the help piggy.

 

[runningrandy04]

well after a week of having nothing in there the ammonia and nitrites were 0 and the nitrates were at 5. I figured that was the benefit of getting cured LR and live sand, plus after a week i was getting a big algae boom and wanted to keep it under control.

 

[Piggy]

Keep an eye on your paremeters. Shrimps are very sensitive to nitrates. I wouldn't add anything else until the cycle is over.

 

[natan]

Many species of H2S producing bacteria lives in oxygen poor environment. (H2S is what you smell and it is a product of protein digestion).

 

[runningrandy04]

I plan on it. I actually wasn't going to get anything else for about 2-3 weeks. Didn't want to add any fish until I got the skimmer I want. I ended up putting the shrimp in early because there were apistasias spreading across one of my small rocks to the big ones.

 

[fatman]

You make no mention of what you might be feeding the shrimp and such. An uncycled tank really can not handle anything other tahn the organics die off from the live rock and sand, and as your parmaeters show it couldn't totally handle that. The fact that your ammonia, nitrites and nitrates are low is probably the results of both the developing bacteria and the water changes. I advocate water changes during a cycling. It preserves more life forms and usually allows the keeping of snaqols during the cycling, however it really is not recommended. If you are getting algae this early in the cycle process then either it is due to die off of something that was living, whether that be bacteria, coraline algae, algae, or snails. Something has to feed algae. Hydrogen sulfide (sewer gas) is poisonous. If there is enough thtyou smelled it, it is doubtful you would have any living shrimp or snails. Your sand bed has not been in plce long enough to have trapped enough detritus in its lowest depths to have produced hydrogen sulfide. You also do not state the depth or particle size of your sand. Unless your talking sugar fine sand, you would need four or five inches of depth to develop the gas you supect. You could possibly develop it in 2.5 to 3 inches ogf sugar fine sand, but not so soon. I would say your not smelling what you fear, but you are smelling decomposition of some sort. I would continue with the weekly water changes, or make them twice per week but half the amoubt of water changed.

 

[runningrandy04]

I haven't fed the shrimp anything yet. I was gonna put about 1/8 cube of mysis shrimp in last night but started getting the smell so didn't. The smell could have been from the die off of some algae. I've been using Phosguard 4 days on/4 days off so that could kill off some of the thick patches of algae that the crabs have been taking their time with. Yea...I'm definately not gonna have any trapped detritus. Sand isn't too fine and its only an inch deep. I'm glad to hear that someone agrees with the water changes during a cycle, so I'm not a complete idiot. Anyway, all the shrimp and crabs are still alive so I was probably just being paranoid about any smell.