Pockets of sand turning black beneath shallow sand bed (pic)

reeferoni · 04/27/2013, 07:36 PM

Hi, I noticed the other day that the sand in one of the back corners of my tank has turned black in pockets beneath the surface... I've heard of this happening in tanks with DSB's, my sand bed is quite shallow (1-1.5 inches tops; the pic is very zoomed-in)

Is this something I should worry about, and can I vacuum the spots next time I do a water change? I usually try to vacuum my sand bed whenever I do a change but this spot is in the back corner so it's been neglected.

Thanks for any feedback you can offer

Sk8r · 04/27/2013, 08:03 PM

It looks green. But black sand (hydrogen sulphide) is lethal stuff. Get some nassarius snails (3 per fifty gallon,) and don't disturb the sandbed. If it does get out of hand move all specimens to a qt tank immediately.

reeferoni · 04/28/2013, 08:11 AM

Thank you for the reply Sk8r... the area above the black sand is indeed green, but the sand at the bottom is truly black even if my crappy camera phone didn't capture that well.

That being said-- YIKES! This sand is less than a year old (replaced when I moved house last summer and upgraded my tank)-- is it really possible that this is deadly, and not just a lot of detritus? Here I was thinking I was being paranoid/overly cautious! I will get those snails asap, although I may need a few extras as I have a 2.5 inch baby clown triggerfish that loves to eat all my snails

Do you think this would solve the problem by slowly releasing the toxic buildup in very small increments that won't harm my corals, or would this just help to prevent further spreading? I never even knew this was something I had to worry about in a tank with a shallow bed... here I am buying a generator and stuff to keep my tank from crashing in the case of a power failure, while a potential disaster is brewing right under my nose.

If the snails would just be to prevent future spread, I'd still be nervous that that sand would get stirred up somehow and kill everything-- I might even empty the entire tank, drain all the water, remove all the sand and go bare bottom if that's what it takes (though I'd hate to remove all my live rock when I just recently got everything looking perfect... but I'd imagine I'd have to to keep beneficial bacteria alive if I drained the whole thing?)

Don't know how this happened... just when you feel like you've taken all the right precautions against a crash...

its very discouraging.

04/27/2013, 08:03 PM	#2
Sk8r RC Mod Join Date: Feb 2006 Location: Spokane WA Posts: 34,628 Blog Entries: 55	It looks green. But black sand (hydrogen sulphide) is lethal stuff. Get some nassarius snails (3 per fifty gallon,) and don't disturb the sandbed. If it does get out of hand move all specimens to a qt tank immediately. __________________ Sk8r Salinity 1.024-6; alkalinity 8.3-9.3 on KH scale; calcium 420; magnesium 1300, temp 78-80, nitrate .2. Ammonia 0. No filters: lps tank. Alk and cal won't rise if mg is low. Current Tank Info: 105g AquaVim wedge, yellow tang, sailfin blenny,royal gramma, ocellaris clown pair, yellow watchman, 100 microceriths, 25 tiny hermits, a 4" conch, 1" nassarius, recovering from 2 year hiatus with daily water change of 10%.

04/28/2013, 08:11 AM	#3
reeferoni Registered Member Join Date: Sep 2012 Posts: 22	Thank you for the reply Sk8r... the area above the black sand is indeed green, but the sand at the bottom is truly black even if my crappy camera phone didn't capture that well. That being said-- YIKES! This sand is less than a year old (replaced when I moved house last summer and upgraded my tank)-- is it really possible that this is deadly, and not just a lot of detritus? Here I was thinking I was being paranoid/overly cautious! I will get those snails asap, although I may need a few extras as I have a 2.5 inch baby clown triggerfish that loves to eat all my snails Do you think this would solve the problem by slowly releasing the toxic buildup in very small increments that won't harm my corals, or would this just help to prevent further spreading? I never even knew this was something I had to worry about in a tank with a shallow bed... here I am buying a generator and stuff to keep my tank from crashing in the case of a power failure, while a potential disaster is brewing right under my nose. If the snails would just be to prevent future spread, I'd still be nervous that that sand would get stirred up somehow and kill everything-- I might even empty the entire tank, drain all the water, remove all the sand and go bare bottom if that's what it takes (though I'd hate to remove all my live rock when I just recently got everything looking perfect... but I'd imagine I'd have to to keep beneficial bacteria alive if I drained the whole thing?) Don't know how this happened... just when you feel like you've taken all the right precautions against a crash... its very discouraging. __________________ -Sarah "The seaweed is always greener in somebody else's lake" -Sebastian the crab