my tank smells like mold

[Seawiych]

Hi,I have a 60 gallon south american cichlid tank that smells like mold.Everything tests out ok.When I touch anything in the tank & smell my hand it smells really strongly of mold.My decor is some store bought driftwood,plastic plants,petrified wood that feels & looks like stone & this was bought at a fish store too,other rocks,& a terra cotta flower pot.I have medium size gravel substate.Over six month's ago I tied a falling apart water pump together with some sisal which rotted & fell apart.Currently everything is covered with brown & black algae.I've never heard of anyone talk about mold problems with fish tanks before.My mom says it smells like mold also.I don't want to get rid of the tank.Any suggestions on what this is & how to get rid of it would be appreciated,thank you.

[Brhino]

when you say "everything tests out okay", what do you mean? What are you measuring and what are the values you're finding?

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

What is the tank stocked with?

What do you have for filtration? How often do you service your filter(s)?

A healthy, well maintained tank should have little to no smell. If we can identify where your maintenance may be lacking, you should be able to improve the situation.

[Seawiych]

I test using those quick dip test strips.I mentioned that everything tests fine but I forgot that my nitrates are a little high on & off.I've been meaning to rehome a few fish because their getting bigger & it is cramped in there.I have 4-albino tinfoil barbs,1-4 line catfish,2-turquoise Jewel cichlids,1-Electric Blue Jack Dempsey,& 1-Geophagus cichlid.I do 30% to 40% water changes two times a month.I'm measuring ph,alkalinity,nitrites,nitrates,hardness,& ammonia.I have 2 hang on the back filters.Each filter filters tanks up to 60 gallons.I clean the filter pads 1 or 2 times a month.I've had other tanks with high nitrate problems before & they never smelled like mold.I have other tanks now & they don't smell like mold either.Hope this helps.

[CGY_Betta_Guy]

how much water movement is there in the tank? If there are dead spots in water flow/circulation this can contribute to cyanobacteria getting a foothold to grow and it smells pretty strong and makes your hands smell somewhat too.

check out the Algae primer ([Only Registered Users Can See Links.]) and see if it matches up with something there.

[Lady Hobbs]

If you are using a HOTB, I bet the smell is coming from that. I've noticed a smell when my filters need cleaning out or if the nitrates are too high in my tank. It didn't smell like mold but just a dank, ucky smell. Have you checked to make sure water was not spilled behind the tank and the flooring is moldy?

I'd do a large water change since your nitrates are too high anyway and rinse out your filter media in tank water.

[gabbyguppy]

Perhaps increasing the water changes will help. Twice a month is probably not enough for a heavily stocked tank.

Also, are you vacuuming the substrate when you do water changes? I vacuum with every water change. I'm shocked at how much crap builds up in a short time.

Karen

[Taurus]

Water changes twice per week may be needed. And I would thoroughly vaccum 1/2 of the tank gravel with each water change.

[Crispy]

definitely increase water changes and keep your filters clean. Clean one filter at a time (providing you're running 2 filters).

[Seawiych]

Thank you everyone for your info.I will increase water changes,cleaning filter pads, & gravel vacuuming up to once or twice a week.The carpet behind the tank in not moldy.What does cyanobacteria look like?Their are some dead spots where there is not much water flow,I'll have to invest in a water pump.What is an HOTB?Thanks

[Michael Milligan]

Activated carbon will take the smell out.

[Taurus]

Water changes are a much faster way to remove the smell than using activated carbon, but yeah, activated carbon will help remove the smell if the smell is being generated by a tank with too much bio-load.

[Seawiych]

Thanks Michael & Tuarus.I will continue doing more water changes & I'm going to buy some activated carbon.I wonder if this mold smell isn't some bizarre type of algae instead.I'm thinking about adding some algaecide stuff to see.If the smell goes away after using it then it is some weird form of algae that people don't encounter too often.

[Michael Milligan]

It occures to me that the smell you are talking about might be the result of the moisture on the undersides of the tank's hood.

Just in case it was not stated, I don't think your fish are in any danger from the smell.

[Seawiych]

Thank you Michael.It's not just under the hood,when I rub my hand on the decor or equipment my hand smells strongly of mold.The fish have been in the tank with it like that way for about a year & their all healthy & growing big.The thing I'm concerned about is that I have asthma & I wonder if it is contributing to my breathing problem or not.I wonder if there is some place that can test a sample to tell me for sure or not if it's mold.