# Sand turning black



## navytom (Oct 31, 2012)

I have had my tank running for about 7 months now with the sand in it. I put some plastic plants in a few months ago and my fish just kept barring them with sand I I would dig them out every few weeks. Today I deside to move them completely to another area so I wouldn't have to unbarry them but I noticed the sand was turning black when the fish started to dig in that area. There's only one post on here I could find about it and it's just on planted tanks. Any help would be nice. Can I leave it or should I take it away or what? I have a really healthy tank with lots of breeding fish, dont want to lose them.


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## Wilson33 (Feb 19, 2008)

Some fish like to uproot plants, or bury them. If your fish don't like the plants, then I would just take them out. What fish do you have?

I am not sure why the sand is turning black. I hate to ask, but do you clean it when changing the water?


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## anthraxx4200 (Aug 16, 2012)

i ran into a similar issue when my plants would die back in a planted setup. to fix it i would simply stir up all the sand when i did a water change. continue more frequently mixing it around and more water changes and it should go away on its own. think about it like low tide, it stinks because there isnt anyone to stir up all that sand


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## DJRansome (Oct 29, 2005)

I see darkening at the glass below the surface of my substrate. I think it's algae and I just scrape it weekly during water changes.

If you've got black in the middle of the tank I'd be careful of anaerobic pockets which can be toxic. You say the fish dig there and the fish are fine?

I'd make sure my substrate is not too deep (an inch is plenty) and I'd churn it with my hand every week during water changes.


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## smitty814 (Sep 27, 2012)

You just need to stir the sand when doing water changes. If you want to keep plants you'll need at least a 2" bed. Too shallow and the fish will easily move the plants.


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## navytom (Oct 31, 2012)

My yellow tail acei's are the ones tht dig it up. They are pushing about 4.5 inches and are always trying to breed that's why they are digging. I don't think that they don't like the plants, but they are just in the way of the breeding grounds so when sand gets moved they get burried. Wilson33 I'm not sure what you mean by clean? Yes I clean my tank weekly but I don't clean the sand.. I just suck up the stuff off the surface. I dot normally stir my sand unless I have to, by pushing over mountains that get made. My Sand is about 1.5 inches deep but with rocks and my fish constantly moving it sometimes the piles get 2-4 inches high. Here resently I've been trying to keep them knocked down once a week after I do my cleaning and water change. Should I just stir my sand more then?


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## DJRansome (Oct 29, 2005)

Yes, especially if you are getting black spots. Churn the sand down to the glass every week.


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## smitty814 (Sep 27, 2012)

I have to disagree with DJ in that the gas produced by anerobic bacteria is harmful. The bacteria use the oxygen molecule from nitrate and this produces nitogen gas which bubbles to the surface and is expelled from the water column. Ppl are always looking for ways to get rid of nitrates. A way of doing so is in deep sand beds. If you however, view the black pockets as unattractive they are easily taken care of by stirring the sand.


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## navytom (Oct 31, 2012)

Hmm well I have stured part of the sand and I had a huge amonnia spike about 20 minutes later. It put my 2 biggest acei's into shock, I quickly filled the tank back up and started my filters back up and it went away shortly. It's not the nitrogen that is harmful it's the anaerobic bacteria meeting the oxigen and the. Dying that is harmful to te fish. I have just never seen the sand turn black from the bacteria and wasn't sure if it was a big issue.


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## DJRansome (Oct 29, 2005)

So maybe take the fish out (bucket or buckets with air stone) churn all the sand, siphon all the water and refill. Just make sure to match your parameters exactly.


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## smitty814 (Sep 27, 2012)

navytom said:


> Hmm well I have stured part of the sand and I had a huge amonnia spike about 20 minutes later. It put my 2 biggest acei's into shock, I quickly filled the tank back up and started my filters back up and it went away shortly. It's not the nitrogen that is harmful it's the anaerobic bacteria meeting the oxigen and the. Dying that is harmful to te fish. I have just never seen the sand turn black from the bacteria and wasn't sure if it was a big issue.


Before I had plants I would stir the sand and then siphon the tank. I have plants now and don't bother with it except that I will stick a chopstick in the sand to release any gasses. Never had an ammonia spike. It's kind of curious why you tested the water while doing a wc and then 20 mins. later filled the tank. Oh well....good luck


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## navytom (Oct 31, 2012)

I only tested the water because my acei's were turning belly up and I couldn't figure out why. I'm just going to start turning all he sand once a week with my water change.


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