Black/ gray spots in sand

[Matthew187]

There are dark spots in the sand in my tank. What are these spots? Are they bad? How do I get rid of them?

 

[WhiteDevil]

I had these in a FW sand bottom tank, it was decomposed matter and poop , I think its due to lack of circulation.

 

[Matthew187]

I have had it set up for about 5 weeks but I still havent had fish so it cant be decomposed stuff theres been nothing to decompose.

 

[WhiteDevil]

Thats what MINE was. not nessecarily* what yours is.

Its anerobic bacteria zones, dont touch them, if you do thhey release toxins and can destroy everything living in the tank. I think as it cycles further they will go away as good bacteria colonizes and takes over. dont quote me but I think that it being anerobic is the issue.

 

[Matthew187]

Alright thank you

 

[cmor1701d]

I doubt you have any hydrocholic acid zones in a tank taht is five weeks old. That would be close to impossible.

Actually anoxic zones are where anaerobic bacteria live, and are what a DSB (deep sand bed) is all about. Black areas in a DSB is where you may have a hydrogen sulfide buildbup. They should remain undisturbed and they should dissapte over time as the DSB starts working,

From another board:
" In DSB with little maturity and insufficient bacterial pops, black areas of sulfate reduction may develop, as well as problem areas of high mineralization of ammonia to nitrate without sufficient denitrification to reduce overall nitrate levels in the system. This may result in substrate blooms of Cyanobacteria and/or diatoms and/or dinoflagellates and/or microalgae"

So how deep is your sand bed?
And I doubt there's much bad going on in only 5 weeks.

 

[WhiteDevil]

Reading more and more it is almost impossible for it to do that after only 5 weeks.
I am finding alot of stuff on it and it mostly all said what Cmor just stated.

 

[melosu58]

Anyway of getting a pic of it?

 

[Matthew187]