DSB discoloration?

[darren]

My DSB is about 3 months old. Lately i've noticed a dark spot developing at a corner of my DSB, at a bottom corner(pic 1). Within 2 weeks, the dark area has expanded to almost covering the entire surface(pic 2). anybody knows if this is normal, and if its not(i suspect), what could be the reason? any help will be greatly appreciated. thanks!

regards,

darren

[darren]

pic 2.

[shiraz]

hmmm DSB maturing? but thats a damn DEEP dsb u got there.. hmmm just 1 question.. what pump do u use to run your 2014??

[darren]

its not really deep, its 6". its only a 2013, not 2014. i'm using a weipro 3000 with the skimmer.

darren

[terryansimon]

could be water seeping through? don't know just. wild guessing. may be wrong.

[darren]

not likely is water seeping through. is a dsb suppose to remain dry underneath the surface?? anyway i added most of the sand after water. so its wet right from the start.

[Achilles Tang]

That's natural.

Probably some hydrogen sulfide produced as a result of denitrification. Harmless levels. Just don't dig up your sandbed!

[darren]

so it means my dsb is now functional? as in it has started in reducing nitrate? thanks AT.

[Fireclown]

Hmm.. that looks familiar! I've got those dark spots in my DSB too. I thought they were algae! haha

[Alentino]

i think it's likely to be pockets of hydrogen sulphide production due to complete anoxic conditions in the sandbed.

sorry to hijack this thread but i have a question about using DSB in sump. is it ok if a just make a DSB in sump without converting it to refugium, that is without 24 hrs lighting and stuffs?

[FuEl]

Of cause it is ok..but your DSB will only remove nitrates. Why people add algae and lights over their DSB is to help remove other nutrients besides nitrates..for instance phosphate.

[CooL_anakin]

Is the hydrogen sulphide harmful? I've got a dark patch in a corner of my refugium. a lot darker than darren's.

[acanthus]

hydrogen sulfide is definitely harmful if too much, reason being-

dead water (still), its stink if it serious.

remedy:- usually with DSB, u need worm, brittle star, snails,etc to work on n inside the sandbed, to give breathing space.

alternatively, b4 start yr DSB, try using many straws with lot of

holes n put them sticking out of the sandbed, overtime u will see

bubbles coming out from the straws.

[Achilles Tang]

Acanthus, that is bad advice.

You should NOT disturb a DSB or it'll never perform its denitrification work.

These anoxic areas/anaerobic areas is where denitrifying bacteria thrives... causing these areas to get oxygen means you'll them them off. Hydrogen sulfide is normal and will eventually find a way to dissipate out on its own by diffusion. No harm will come to your reef inhabitants as such.

If you disturb the deep sand bed and release hydrogen sulfide all at once, then its your own look out.

[nleong]

well, I know I lost a few frags when my PH loses its grib one day and blow up the whole sand bed in my old tank.

so better heed AT's advise, dun disturb your DSB

[derf]

Acanthus, that is bad advice.

You should NOT disturb a DSB or it'll never perform its denitrification work.

These anoxic areas/anaerobic areas is where denitrifying bacteria thrives... causing these areas to get oxygen means you'll them them off. Hydrogen sulfide is normal and will eventually find a way to dissipate out on its own by diffusion. No harm will come to your reef inhabitants as such.

If you disturb the deep sand bed and release hydrogen sulfide all at once, then its your own look out.

Hi,

Wat I read on DSB is that it needs bristtle worms to stir the inside so that it'll will not clog up and eventually crash.

so wat is correct?

[Asfur]

So many opinion around DSBs, i want to experience in DSBs system, but still confuse because there is no conclusion. AT's, sorry not mean to against you, but i ever read that denitrification will give good effect if do in the right way, but it will har the system if the flow is too slow because it will produce hydrogen sulfide and will harm the system. Any comment?

[Alentino]

yup AT, that's what i read in many books too, you need some suitable critters, note the word suitable, to stir up only the top layer of sand to prevent total anoxic region in the DSB which will then cause hydrogen sulphide build up. isn't that correct?

[CooL_anakin]

http://www.rshimek.com/reef/sediment.htm

This should help...

[terryansimon]

what I'm going to do is I'm going to have a DSB in the main tank. up to five inches of it. and ontop of the fifth inch., I'll lay down a thin netting and ontop of that netting, I'll lay down a one inch thick of Grade 1 sand. this will allow my sand sifters to go through the sand, whilst preventing them from touching the main seabed. (=