DSB Heresy

I had this system setup in my 125G tank for about two years. When we sold our house I had to tear down the tank. While I took no scientific measurements, I observed a few things. My fish load was not very great (2 clowns, 1 foxface, 3 small crhomis, mandarin). I felt that I overfed (2 cubes of frozen every other day) When I removed the sand from the tank, there were no black spots underneath. The sand had a fishy smell but nothing overpowering. I drained the plenum once a month, about 1/2 gallon each time.

Like I said, I took no scientific measurements, but I "feel" that it did my tank more good than harm.
 
there are pics in my gallery. I used 1/2" cpvc pipe. holes were drilled about 2" apart alternating between a 10:00 orientation and a 2:00 orientation. I think the holes were 1/32" dia, but I don't really remember. It was the smallest drill I could readily find.
 
I figure it was time to reply to this very old post.

Three years ago when building me 280 inwall I decided to try the CPW method w/ my DSB. I also had a 110 gallon Fuge that was barebottom (so I could siphon detritus). I have regularly drained 5 gallons a week from my CPW. The sandbed to date is full of life, it is as white as the day I installed it and it has not turned to cement. My NO3 and Phosphate level continue to be undetectable.

It is still too early to call this method a success, but I must say I continue to be pleased w/ the results.

This success also includes a major disaster last August. A friend was watching my house for me. The auto top off float was stuck closed and the water level in the tank dropped significantly. He decided to fill by hand from my 44 gallon brute container. This occurred the day I returned home. He ended up taking the lime from the bottom of my brute container. When I got home the PH in the tank was 9.5. I lost most of my corals and fish. I was lucky that I had 2 gallons of vinegar that I put in the tank to lower the PH. The tank has recovered. But, even this incident didn't destroy the sand bed.
 
Thanks for the update. I was just thinking about this thread the other day. Glad its working for you!
 
Hey BigDaddy, thanks for the update.

Do you ever test the waste water for anything to see what it is exporting?

Joe
 
Yes, low levels of phosphate in the .2 range using a LaMotte test kit.

The tank water is undetectable.

Ph in the tank is 8.4, CPW water 7.9

NO3 in both is undetectable.

The waste water also has a faint hydrogen sulfide smell.
 
well...i'm convinced. i'm going to put a CPW in my new 120. I'll let you all know how it's going in 5 yrs LOL.
 
I wonder if maybe you are exporting a huge amount of bacteria with a lot of phosphate bound within that does not show up with your phosphate test.
 
Thanks for the update Big Daddy :D
Do you have any info on how you constructed the CPW.
I am interested in the size drill you used & what different layers of substrate & the screen you used.

Lived in Tucson back in the late 70's with a friend for about a year. Loved Nogalas & Arizona Hyws Mag. & Bobs Big Boy !!

:thumbsup: :thumbsup:

Thanks for a reply.

Steve (@^ 926


:smokin:
 
I really enjoy Tucson, I've been here since 1983.

Here's a link to my 280 inwall's construction, there's a picture of the CPW. I used a 1/8" drill bit w/ holes about 4" apart, they were closer together the farther it got from the drain point.

http://www.reefcentral.com/forums/showthread.php?s=&threadid=366943&highlight=280

The plenum is covered by drainage cloth. Then there's about 2" of crushed coral, the crushed coral is covered by two layers of drainage cloth and the 4-6"s of southdown on top.

I know this system is not a fan of barebottom owners or die hard DSB owners. But I figured it was too hard to keep a DSB perfect and I don't care too much for the looks of a bare bottom tank.

I believe this system is very forgiving. I'm no chemist, but the CPW water doesn't look very healthy, so if you have to do water changes why not remove the bad water out of the tank.

My 2 cents.
 
The Hach test kit will test for inorganic phosphates, but its a real pain in the butt. You have to boil the sample, etc. If you're reading any inorganic phosphates, you're just seeing the tip of the iceberg. Inorganic phosphates are usually only present for a short period of time because they get taken up by algae so fast. Organic is the real problem, and you cant test for that anyways. Easiest way to tell is how fast algae will grow, since it'll get the phosphate before you do...
 
Thanks for the reply Big Daddy

Were the holes drilled randomly around the pvc every 4".
Do you drain the CPW by a syphon method with a simple tube & valve or a power head plumbed into the drain. is the drainage cloth an HD or Lowes item, & have you noticed any deteroration of it by now

Sorry for all the questions I am ready to start filling my display ( 50 gal. acrylic ) with a DSB and I think draining anything toxic from it is a good idea. I have read both pro & con statements about the use of a plenum, But the CPW concept is interesting. Did you use 1/2 or 3/4 pvc.

I appreciate your time & opinion on this. I would like to get the display up and running soon.

Steve (@^ 926

:smokin:
 
There are pictures of the plenum piping I installed in my 120 in my gallery. That tank was up for ~2yrs, and I never showed any 'trates. I drained about a half gallon every water change (monthly). Drain water really started smelling foul if i let it go too long between water changes.
 
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