DSB Cleaning

[tkhawaja]

Originally Posted by StirCrazy

is your bed remote from the main tank?

Yes, it's a partition in the sump. About 20G where I have a 8" DSB and also use it as sort of a refugium.

[Aquattro]

Originally Posted by StirCrazy

I don't think Brad can say for sure it was because he put new sand in or because he reduced his depth as the sand he had in there had contaminated stuff from another source so he never tried just reducing the depth as he HAD to replace his sand.

Steve, you'll recall that the right side of the tank, which was the worst, had been reduced over 2 months to half it's original depth. Even when it was less than 2 inches, that area continued to grow the brown slime. You're right though, I'll never know for sure what it was about the sand that caused it.

[Scales]

There are currently a couple of long threads on RC dealing with these issues. Not being computer proficient, I am unable to provide a quick link. I recall one being labelled "DSB Heresy" or something of that nature. There is much discussion about the "standard" DSB theory, which is often attacked. Some propose modification to accepted DSB "practice", including the management of anaerobic/anoxic zones within a sand bed. There is also discussion of phosphate binding.

Interesting for both its content and the heated discussions/personal attacks among the proponents of conflicting theories.

Cheers.

Trevor

[ron101]

Yes those RC threads can take on life's of their own. Unfortunately lots of good info gets lost in the works.

IMO the main point to take home from them is that total bio load is important whether you have a fish only setup or a 'balanced' reef system, bare bottom (not the kind that you sit on ) or a DSB. The odds are that without some form of intervention beyond adding food, Ca, Alk, and top off water, the system will eventually crash. For an aquarium to be a self balancing ecosystem like a real reef then they would have to be a, well, real reef.

I think that I will be replacing my sand with a shallower bed of coarser grains and place less emphasis on critters and more on manual labour. May as well give a different method a go for 3 years and compare.

[IslandReefer]

Originally Posted by reef_raf

My (wrong) thoughts also. I tried doing that, but the algae continued. The PO4 accumulation also inhibits coral calcification, which I did notice as well. Denitrification does continue (it is not a function of the media composition, only size) although the 4" inches recommended by Dr. Ron isn't required. The aragamax bag actually says only 1" required, and I have found this to be true. In fact, a tank with the proper amount of quality porous rock should have 0 nitrates.
I believe that most people will need to remove their sand when it hits the 4year range. This should also be a consideration when purchasing used sand. The bad stuff comes with it!!
What i did was remove all my sand, and I added 2 bags of new sand. I am so far please with the results. I have a large selection of sand fauna, 0 nitrates, and the tank is now 3 inches deeper than it used to be.

Out of curiosity, did anyone with "PO4" contaminated sand, acidify it to disolution and then test for PO4 to see if there a significant amount bound then released?
John

[Beverly]

Originally Posted by ron101

Beverly the thoughts are that nutrients (particularly phosphates) bind to the sand and then begin to release once it reaches a certain level.

Okay, I can understand that in some reefs nutrient buildup would be a real problem, especially if there is no natural means of export, such as a refugium or macroalgae in the display tank. MA, like house plants, plants in a planted FW tank, etc., need P,N,K for proper growth. P = phosphate, N = nitrogen, K = potassium. I'm thinking that if a tank has macroalgae somewhere in the system, nutrient buildup shouldn't be that much of a problem, even for phosphate which MA would certainly use.

Just a thought, anyway.....

[StirCrazy]

Ok sence this won't die I will explain my point of view on the phosphates issue for more clarification.

if you look at natural process of binding in the ocean you will find that Mg grabs the Ca moliques and basicly seals them off by binding them untill the Ca is nutraly charged. This has been pointed out my RHF and a few other chemists.

the problem where I could see phosphate binding to Ca is if your tank is Mg difecient and Phosphate rich, you might have phosphate binding because there isn't enuf Mg to do it.

but if you have a proper range of Mg you should get Ca that is "Mostly" Mg bound because Mg is much higher on the reactive list than phosphate. (I am going off memory on this one so if some one has a reactive eliments chart that shows different let me know)

Steve

[ron101]

Hey Brad, what would one use as a source of HCL? Bleach? I have some coarser grains mixed in that I might try to cleanse.

[BCOrchidGuy]

One thing you can count on if Dr Ron says the moon is blue, in a year he'll say we misunderstood him or, he was misquoted. OR, he may even admit he was wrong but the fact will still be, his mind has changed, so what he said a year ago, is out, the new gimmick is.....

Just my two cents worth. I'll not mess with a DSB anymore, I didn't have trouble with mine at all but I know I can get good filtration in a 2 inch sand bed because I did it, when I took my refugium out of the picture.


Doug

[StirCrazy]

Originally Posted by BCOrchidGuy

Just my two cents worth. I'll not mess with a DSB anymore, I didn't have trouble with mine at all but I know I can get good filtration in a 2 inch sand bed because I did it, when I took my refugium out of the picture.


Doug

2 inch is still a DSB, just not as deep as a 4" one.. I think to not have a DSB you have to be shallow enuf that you are not getting denitrifacation as a result of the depth.

Steve