Sand Sifters and a DSB

[SquishyFish]

For the last several years I have been a big supporter of NOT including sand sifters in a tank with a DSB. Sand sHifters....yes, but not siFters.

Well..my tank crashed again last week and we cant figure out why. Ran the gambit on the water test and all came back with in acceptable ranges. Granted, Trates and PO4 were a little high, but only enough to cause cyano and nuisance hair algae. Not enough to kill fish. (back to the trates and PO4 in a min)

Well, I lost 4 fish all with in an hour...yellow tang, velvet fairy wrasse, Melanaris wrasse, lawn mower blenny, and a yellow head. All reasonably hearty fish.

Now the weird part...Most of my inverts made it (including various snails, a conch, and a CBS) ...and my dragonet. Arent they suppose to die at the drop of a hat?

Anyway...I say all that to say that I wonder if the nutrients in the water that are obviously feeding the hair algae might be part of the problem. A sand sifter, Such as a Orange spot goby will do wonders for keeping the sand clean and free of detritus.

I have approx 350-400lbs of Live rock in the tank. A mandarine that eats frozen food and a 3 inch sand bed.

I am seriously considering breaking my own rule and putting a large sifter into the tank.

Opinions?


(also...the had a major crash a year ago when the LFS didnt move it properly and basically killed all my coral. I am just now in a financial position to start restocking the coral. There are no corals in the tank right now.)

 

[SquishyFish]

Bump

 

[midiman]

Do you suspect toxins from the DSB? I'm not sure I get what you're intimating. Are these toxins known to be more toxic to fish than to inverts?

I'll do some research, too, but I'm sure you've done your homework on this. I read somewhere (sorry I didn't bookmark it) that the risk of toxin release from a DSB is minimal. The old plenum-type beds were far riskier.

There's sometimes TOO MUCH TO KNOW with this hobby!!! (But I love it).

For instance. I now know that it is possible to kill a bangghai cardinal with a flashlight. Yep. First-hand experience with that one.

 

[DeNero1331]

I believe I read somewhere that if you don't have an adequete sifting of the sand then the nitrogen can pile up and when it is released it can hurt your fish. The sand sifters release the gas from the dsb in small increments which make it less harmful.

It sounded wrong to me but maybe that is what's happening to your tank. I have a horseshoe crab sifting like crazy in mine.

 

[midiman]

Yes but the whole point of a DSB is to create hypoxic areas so that nitrogen gas (which is inert and harmless) can be produced from the nitrates in the tank. SIfters would introduce oxygen and prevent this from happening. It is the potential of ANOXIC regions and the production of toxins (hydrogen sulfide gas, I think ??) that make it a risk.

Darn I wish I had saved that article on DSB pros and cons. SOmeone might want to correct me on this, but it seems silly to have deep sand (5" - 6") if you are going to have sifters, doesn't it? A thinner bed would do fine for burrowers, etc., without the concern of toxins. (Nothing against sifters, but the LFS in my town has a tank full of sand sifting stars that he NEVER SEES because they spend ALL of their time under the sand.)

 

[quarryshark]

I had 2 in my 210 for a little over a year and I would never do it again. The almost completely depleted my pod population and eventually wasted away. Could never get them to target feed either.
IMO a good population of pods and worms will do a much better job of sifting the sand and be much more self sustaining.

 

[sirfishmaster]

i have a 55 gallon with about 5" of sand and a sand sifting star, but i noticed it only sifts top 1/2 max along with my nasaurius snails. Look under your tank (if you can) and look for black spots..this is a good indication that gas is building up.


doug

 

[SquishyFish]

LOL...Okay..here is the short version on DSB's

Sand SiFter and sand sHifters are completely different. Sand siFters filter the sand through their mouths and out thier gills specifically looking for micro-organisms. These micro organisms are crucial for a sand bed to function properly. They burrow through the sand and sHift (theres that word again)...shift it just slightly. This slight movement keeps the sugars in the bacterial film from binding the sand together and trapping Sulfides. When you remove the benificial micro-organisms from a DSB the sand becomes stagnant and will eventually develop what is known as Clumping syndrome. Because the sand siFters only move the top inch of sand, the lower layers "clump". If one of the pockets of sulfide is ruptured, it can quite literally kill a tank in minutes.

I have what I call a Shallow DSB. It is only 3-4 inches deep...not deep enough to form Sulfide pockets, but just deep enough to function as a DSB.

I have a detailed article on my web site if anyone wants a more technical look at it.

 

[DeNero1331]

I did some thinking... since hypoxic is only a partial lack of oxygen and anoxic is a total lack, wouldn't we want some sifting? Maybe not constant sifting but just enough to release any gass build up and introduce a possible small amount of oxygen?

Anyone know if that's close to being possible?

I only let my horseshoe buddy sift my main tank. My fuge gets the worms and pods.

 

[SquishyFish]

I had 2 in my 210 for a little over a year and I would never do it again. The almost completely depleted my pod population and eventually wasted away. Could never get them to target feed either.
IMO a good population of pods and worms will do a much better job of sifting the sand and be much more self sustaining.

I guess the detritus can be cleaned by the crabs and such which will keep the nutrient level down.

My wife just emailed me the #s on the tank

PH - 8.4
Ammonia - 0.0
Nitrite - 0.0
Nitrate - 25 ppm
KH - 8.0
Calcium - 440

 

[SquishyFish]

Denero
I have never heared of any of the proponents of DBS's using anything other than shifters to move their sand bed. Usually its pods, worms, and conchs like QuarryShark mentioned.

 

[sirfishmaster]

I have a detailed article on my web site if anyone wants a more technical look at it.[/quote]


i read it very nicely written



doug

 

[SquishyFish]

Thanks, but I cant take credit for it. Its written by a very well known figure in the world of Reef keeping. Ronald L. Shimek, PH. D.

I wish I was that experienced with the hobby.

 

[quarryshark]

I guess the detritus can be cleaned by the crabs and such which will keep the nutrient level down

Thats what I rely on. My hermits, shrimp, stars (serpents) and even my Cowrie seem to do a good job. My sand is cleaner than ever.

 

[quarryshark]

Well, I lost 4 fish all with in an hour...yellow tang, velvet fairy wrasse, Melanaris wrasse, lawn mower blenny, and a yellow head. All reasonably hearty fish.

Maybe out in left field, but did you introduce any new fish recently? Were there any symptoms such as lack of eating, flashing, etc or did it just happen out of the blue?
Just seems strange that the inverts were not effected, also the surviving fish are rather resistant to parasitic outbreaks.
I know you are rather advanced in your knowledge so consider this just a reach... :?
BTW, sorry for all your troubles.

 

[midiman]

It does sound like a singular event to wipe out fish in such a short period. IF there anyway to test for the presence of sulfides (other than being there to catch the stink?).

Oh, and, bubbles in a properly functioning DSB are likely to be nitrogen gas, whihc would be a GOOD thing.

From the MANY hours I've spent reading on this, it seems that a DSB should not be deeply sifted. If it is, it's a deep layer of sand, but not a functioning DSB in terms of nitrate removal. My DSB is in my sump, where I hope that any "Sump fart" sulfide gas release would dissipate well before entering my main tank.

 

[SquishyFish]

Well, I lost 4 fish all with in an hour...yellow tang, velvet fairy wrasse, Melanaris wrasse, lawn mower blenny, and a yellow head. All reasonably hearty fish.

Maybe out in left field, but did you introduce any new fish recently? Were there any symptoms such as lack of eating, flashing, etc or did it just happen out of the blue?
Just seems strange that the inverts were not effected, also the surviving fish are rather resistant to parasitic outbreaks.
I know you are rather advanced in your knowledge so consider this just a reach... :?
BTW, sorry for all your troubles.

We had introduced 3 new fish over the last two months. All were in ideal health. All eating..none flashing. None were shy...all ran to the front glass when we walked up looking for food. Except for the hair algae and the PO4 we are fighting the tank and fish were in ideal health.

As far as it being weird that the inverts were not effected and how sudden it was....thats what everyone is saying. I have a friend who is a marine biologist. He has no idea what caused it. In my 12 years of keeping saltwater I have never seen a crash like this.

 

[SquishyFish]

It does sound like a singular event to wipe out fish in such a short period. IF there anyway to test for the presence of sulfides (other than being there to catch the stink?).

Oh, and, bubbles in a properly functioning DSB are likely to be nitrogen gas, whihc would be a GOOD thing.

From the MANY hours I've spent reading on this, it seems that a DSB should not be deeply sifted. If it is, it's a deep layer of sand, but not a functioning DSB in terms of nitrate removal. My DSB is in my sump, where I hope that any "Sump fart" sulfide gas release would dissipate well before entering my main tank.

The shifting of the deeper parts of the DSB is minimal. Its basically a worm or a pod working its way through the sand. You would never see the movement or even know the critter was there unless you went diging through your dsb. But the shifts are enough to keep the sand from clumping.

As far as the Sulfide release. It hits the water first...you pump will push the water into the tank pretty quickly. It may lessen the effect, but it certainly wont eliminate the effect.