Rejuvinating an established dsb

Moort82

New member
Think i'm at the stage when i need to either revamp or restart my dsb. The system is 8 years old and the dsb has been on it for most of that. Never had an issue with nitrate since it has been on there but within the last couple of months i've noticed the nitrates begin to creep up. There haven't been any other changes to the system but with work really taking over and very little time for maintanence, i must admit i dropped the ball and didn't notice the flow in the dsb was next to nothing.
This could have happend anywhere in the last six months and what i believe has happend is the bed has become clogged/suffocated with detritus. It's hard to tell if this is the case as due to the age of the bed i know there will be alot harmless silt in the bed as well but it appears really dirty and there is hardly any life.

So my decision is to either strip the whole thing and start again. Not overly keen on this because if it is contributing i don't want to remove part of the filtrtion from the tank.
The other option is to clean parts of it over the next few weeks/months. Allowing it to be recolonised and refreshed plus reseeding it with life.

Would love your input or any other ideas. Do you think just restarting would have any major effect. As i say time is limited working a minimum of 6 days i don't really have much time for extra maintanence when the filtration is restarting itself.

TIA
 
Hi, Its a remote dsb and its my undestanding that anything that disturbs the natural layers in the bed will reduce its efficiency. I'm not sure if adding anything will be able to bring it back to a functioning bed.
 
Is it possible to start using bio-pellets to take over for the DSB? Could you bypass the remote DSB after the pellets have colonized, and then replace the substrate in the DSB?
 
A DSB is anearobic (without oxygen), what would you expect to find living in it except anearobic bacteria and maybe some other anearobic tiny stuff. How big is your system (total water), how big is the DSB and what does "nitrates are creeping up" mean? I keep some nassarius snails in my 2' x 2' x 6" DSB. They keep the top layer clean and turned over but they don't go deep and disturb the lower layers. My system is about 350g and I haven't had any nitrates since 2 months after setting up the DSB.
 
Only the lower sections are anaerobic. The upper layers should to some degree contain oxygen. The anaerobic area is barren of life yes but i mean the top layer as well which should have worms, pods etc. If you look at the dsb from the sides then there is very little burrowing activity like you expect and i can't say whether these are old or new. You also can't see any of the tell tail signs of nitrogen bubble in the cross section.

The system volume is around 300 liters with around 100 being the refugiumabove the dsb. The nitrates have crept from barely detectable to between 10-15 and i don't want them to increase further. As i say i haven't added anything to the tank, maintainence has been the same (although upped the waterchanges now) and the only cause i can see is the failure of the pump and increase of smutz in the dsb.

I'm not saying your wrong but i'm pretty sure that Dr Shimek has said that you shouldn't add any large burrowing critters to the dsb as they break up the different oxygen areas. Instead what you should rely on are the tiny worms and other critters allow the water to gently percolate through the sand.
 
Is it possible to start using bio-pellets to take over for the DSB? Could you bypass the remote DSB after the pellets have colonized, and then replace the substrate in the DSB?

Hi, thanks, i hadn't actually thought of that tbh. I'm not sure i'd have the time needed to play with them and get it right during setup, plus with this system the skimmer isn't the greatest and i don't think it would cope with the increased waste. I'll definately look into it as i have been thinking of improving the skimmer but tend to run my systems more naturally.
 
Gotta say I run a 4 inch DSB and I vacuum the top inch or so. Tgr water I suck out is brown and its never effected my trates. There is a good post here somewhere someone started going deep into his DSB. I only say this cause there is wide opposition on tgr au next of disturbing it. FWIW I have a heavy stocked 75 with three tangs and 4 small fish
 
Gotta say I run a 4 inch DSB and I vacuum the top inch or so. Tgr water I suck out is brown and its never effected my trates. There is a good post here somewhere someone started going deep into his DSB. I only say this cause there is wide opposition on tgr au next of disturbing it. FWIW I have a heavy stocked 75 with three tangs and 4 small fish

Is this the thread you're talking about?
http://www.reefcentral.com/forums/showthread.php?t=2125242
 
I have a 6" DSB, it's about 6 years old now, and I never touch it. I have a good population of sediment fauna, and a couple of conch's that keep it pretty well turned over. I think if you find that your SB has solidified, it would be best to replace it, and recharge it. I used these folks for activating the substrate:

http://www.ipsf.com/reefworms.html
 
I have a 300 gallon round rubber maid tub with 12 inches of sand running for over 3 years. I had to remove a large LTA a few months ago because the hosting GSM clowns went crazy and started ripping tenecles off. That LTA was actually attached to the bottom of the tank in that 12 inch sand bed. If you have ever played in the sand at the beach then you can imagine how wide of a hole you have to make to get down 12 inches under water in a sand bed. The purpose of this story is too say that disturbing the sand bed had no effect on the corals in the tank. I know this is an old thread, but I thought i would share for whoever may read.
 
The only way I finally got my nitrates under control was to get rid of the dsb in the sump and start aggressively syphoning the one in the tank. I think after a few years the dsb stops doing its job.
 
Fact is the first inch or so of substrate are where the beneficial bacterial activity occurs.. it has been know for some time that nitrifying bacteria occur in the top layer of the substrate and not in the lower regions of the sand bed(bacteria form colonies and create their own environment)... personally I would pull the sand bed and put in a 1" to 2" bed myself.
a DSB can become a sink for PO4 and refractory organics(basically organics carbon would remove) and through time sulfate reducing bacteria can form releasing hydrogen sulfide as a byproduct...thus why it can be a blessing at first(PO4 sink) and a curse later in life(crash the tank) and also why you should not touch the bed(well at least below about an inch or two).
With little benefit and possible drastic changes happening to you tank soon...remove it.

Oh, almost forgot... because of the possible hydrogen sulfide danger...remove the bed all at once...break down the tank, remove bed, clean tank, replace with new substrate, add back in water new and old then aquascape. You'll be good to go... with the shallow bed you can maintain it safely.
 
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