Fishless cycle smells like mildew 1 week in

Ashibashi · Aug 20, 2021

Hello all,

I've been cycling ~20 lbs of pukani dry rock in a brute trash can for about a week now. I put some turbostart in there and have been dosing it with ammonia every other day or so when it drops below ~2ppm. I noticed a kind of funky musty smell from the water the day before yesterday and did about a 50% water change, then dosed ammonia again. It was about 4 ppm then. Today it still smells like mildew. I didn't soak the dry rock or anything before I put it in there from the box it shipped in. Was told it had been sitting in a big covered trash can outdoors for a long time after having been bleached and cleaned before it went in there. Also the water feels kind of slimy on my hand.

No fish or anything alive is in there. What could be producing a moldy smell? About to do another water change but very curious as to what could be going on.

ReefGeezer · Aug 20, 2021

The Brute that I store fresh water for my ATO smells like mildew so it may be nothing. If the rock had already been in a tank, it may have had some dried out internal organics that are now rehydrated and decomposing . That'd make some smell and add a little funkiness to the water. You shouldn't need to add any more ammonia... 4 ppm is a little high. A small filter with some GAC in it might help if the slimy feeling or smell gets worse.

reefz · Aug 20, 2021

It’s cause your using turbo start. That stuff smells terrible. I’d do a water change and use a different bacteria brand. Dr tim one and only or seed is what i use because it doesn’t smell

ReefGeezer · Aug 20, 2021

You really don't need any more bacteria in a bottle products. They cultures are already there. It just takes time for them to get to a effective population level. Circulation, maybe a little filtration, and patience is all you need.

Rubberfrog · Aug 20, 2021

Add some circulation, if you haven't already, and leave it alone for at least a few weeks. Its going to stink while that rock cures.

Jekyl · Aug 20, 2021

Are you

Ashibashi said:
Hello all,

I've been cycling ~20 lbs of pukani dry rock in a brute trash can for about a week now. I put some turbostart in there and have been dosing it with ammonia every other day or so when it drops below ~2ppm. I noticed a kind of funky musty smell from the water the day before yesterday and did about a 50% water change, then dosed ammonia again. It was about 4 ppm then. Today it still smells like mildew. I didn't soak the dry rock or anything before I put it in there from the box it shipped in. Was told it had been sitting in a big covered trash can outdoors for a long time after having been bleached and cleaned before it went in there. Also the water feels kind of slimy on my hand.

No fish or anything alive is in there. What could be producing a moldy smell? About to do another water change but very curious as to what could be going on.

Are you circulating the water?

Ashibashi · Aug 20, 2021

reefz said:
It’s cause your using turbo start. That stuff smells terrible. I’d do a water change and use a different bacteria brand. Dr tim one and only or seed is what i use because it doesn’t smell

It does totally smell but not like mildew. When I first threw it in there the water smelled like pungent low tide, which wasn't unpleasant to be honest. This smells like I left a load of towels in the washing machine for a week.

I just did the water change and I noticed that a cloud of brown grey dust came up from the bottom. The rocks didn't look dusty when I put them in there at all, definitely not to that extent. I suppose the dust could be some sort of biological precipitate and something living was producing the smell.

I stuck my face right in there and I can't detect a smell now. Also the nitrates were really high before - I did a 1:10 dilution and it still maxed out my hanna low range reader. Does some nitrogenous compound produced by bacteria smell like mildew I wonder?

At any rate the issue is temporarily solved. Curiouser and curiouser!