DSB Heresy

Dr-BYTES said:
i have 1/2 in schedual pvc 40 pipe which is pretty thick stuff u think a 1/16 holes would be ok or must it be 1/32

That is dependent upon the size of your tank and the rate of CPW. Figuring you will remove about plus or minus 1 gpm. A larger tank may want to drain at a higher rate.

If you drilled 1/16" holes, i would estimate that each hole would approx. drain about .05 gpm. Or 20 ( 1/16") holes would be needed in total to drain 1 gpm.

For 1/32" holes you would need 80 to 100 holes to drain 1 gpm.

This will give you some ball park numbers to design around.
 
Curse you IdrHawke.
Now I will always be looking at my DSB wishing I had pipes under it. Just one more thing to make my tank libido inferior.

Oh well, I wanted a different tank size anyway...
 
the drain cloth from home depot i can get is used for gardens
laid under topsoil to prevent weeds from growing its colour is black one side of the cloth is sorta shiny and the other dull is this ok
 
Dr-BYTES said:
the drain cloth from home depot i can get is used for gardens
laid under topsoil to prevent weeds from growing its colour is black one side of the cloth is sorta shiny and the other dull is this ok

If I remember correctly that material is more like a fine screen. They also have a gray felt like material, that would do a better job of keeping the fines from plugging the holes in the pipe. I bought a whole roll of it and have enough left over to do 100 tanks. If you want to pay postage let me know how big a piece you need and I'll mail it to you. Just drop me a private note with your address.
 
ok the material i have is dark grey and is like felt. i am finnished designing and and drilling my grid do i have to glue each joint
the piping fits pretty snug in the joints just wondering if gluing each joint is required
 
Dr-BYTES said:
ok the material i have is dark grey and is like felt. i am finnished designing and and drilling my grid do i have to glue each joint
the piping fits pretty snug in the joints just wondering if gluing each joint is required

Not required but a good idea. It isn't worth the trouble it may cause to have a joint come undone for any reason after it is installed and covered with substrate. How large is your tank?
 
Wow... .long thread.

Simply brilliant idea...I can't believe there is even a question on it...it's soo obvious once someone points it out. I actually thought about putting a drain in the bottom below the plenum so I could siphon off the stuff years ago, but spending a week tearing down the tank for it....well, I'm too darn lazy.

I don't think you're losing denitrification...a rapid pull of water into the bed once a day, I don't think would effect it that much...have to look up denitrification flow rates in the denitrifying filters. But chances are with a 4-6" bed, you are not replacing all of the water in the bed daily....that means it's still a low flow rate, although you may still be losing some of the effect.

Also, I wonder about using fine grain sand. In conjunction with standard DSB "critters" it might be fine. You're not going to really lose any flow rate, it's just a matter of creating channels and concretion of the areas that aren't channeled. Good churning via jaw fish, wrasses, worms, cukes, etc could minimize this????

Just a thought.

I SERIOUSLY doubt you will see any detrimental long term effects. It doesn't make sense on what is already known with DSB's, and UG's.
 
My tank is 65 gal and may i say idrhawke you may very well have the solution to whats been troubling reefers all these years. Some times the simplest answers to complex questions turn out to be correct i wonder how many years went by when man pushed square wheels before some one came along and said hey lets cut the corners and a era was born. either way if your method works or not in the long term. At least u stepped up to the plate and took a shot and for that i thank u.
 
ldrhawke,
Just thinking out loud here, of backwashing the filter cloth.
I would think that you definitely wouldnt want to do this until you have been wasting from the plenum, bed, etc for awhile.
If you backwashed the drain system without wasting first, it could send a very toxic mix back into the water column. I agree that you may need to backwash the drain, but this should be pointed out. It'd be a tragic mistake if done improperly.
Thoughts?
 
H20ENG said:
ldrhawke,
Just thinking out loud here, of backwashing the filter cloth.
I would think that you definitely wouldnt want to do this until you have been wasting from the plenum, bed, etc for awhile.
If you backwashed the drain system without wasting first, it could send a very toxic mix back into the water column. I agree that you may need to backwash the drain, but this should be pointed out. It'd be a tragic mistake if done improperly.
Thoughts?

Excellent point.....this is one of the reasons I recommended back washing for only 15 to 20 seconds in one of my posts.

I don't think you will have that highly toxic build up with regular CPW draining, but it would probably be smart to follow the short back wash burst with a water change by draining out of the CPW system to help pull what you might have disturbed back into the drain. I don't think you would need to back wash more than once a year.

There is still a lot of information to collect to optimize the CPW concept. I wouldn't be surprise to find people that simply didn't partial weekly manual water changes using the CPW system and draining through the bed, found that it avoided the potential of DSB over load.
 
What a good concept. I'm very new to reef keeping and have been researching to find the best way to set up my tanks, switching from FO. How fast do bacteria recover or multiply? I read somewhere that the amount of bacteria in a sand bed could double very quickly, and reproduce to the space and food limitations. It seems to me that not only are you removing the bad stuff from the bed but also any die off would create more room for the bacteria to multiply.

If you could slide or rotate the drainpipes could you further reduce the channeling by having the holes in slightly different locations?
 
here's a pic of the system that i was setting up a while back with the same concept. the 300 gallon ruber maid comes with a drain hole. the pvc in the pic is cut with numerous two inch slites and thus the water is taken from the full area more or less under the phlenum. see attached pic

i just got a error message saying pic is to big ..any ideas on a get around for this on the to big pic?
 
if you are using the upload feature, then you need to resize the file with photoshop or some other imaging editing software that lets you resize.
 
Hi ldrhawke,

Can you give us un update on how the nitrate measurements in your water column are doing? Are you now feeding as much as you were before adding CPW to your tank?

Thanks,
D
 
Greetings all,

I going to build my CPW\DSB\Coil-Denitrator and install it within the next 2 weeks.

Just a question regarding the flow through with denitrification systems. How much is the flow?

And with the design I was thinking of having +-3-5 drain holes drilled at diffrent points in the plenum to extract the water from, the reason being is that it would take water from various places inthe plenum and would move the water more evenly down through the plenum and not have fresh water move through the DSB at only one point.

Does this sound like it will be worth it as I will be running a constant flow through 2 of the drain holes and a wasting for a couple of seconds from the other drain holes.

And input welcome.

Thanks
 
I seem to recall back in the late 80s/early 90s that some company (I don't recall the name) sold a modified UGF that had a space underneath the plates that slanted inward, allowing any solid material that made it through the gravel to be siphoned off through some kind of valve. While not exactly the same system that's being discussed here, it would be interesting and relatively easy to retrofit UGF plates to form a plenum with a valve to drain the water from underneath. Perhaps it would be an easier and/or cheaper way to achieve similar results.
 
This seems like a very plausible concept. If I was planning to set up a new reef anytime soon, I would definitely employ this method. I have seen and smelled what happens to a old DSB when taking tanks down in the past. To pull that nastiness out on a daily basis seems like a wonderful idea. The small amount removed would probably have little to no effect on the nitrite and nitrate processing bacteria distributed about the sand bed.
 
Hi John, How long did you let your substrate cycle before you started your controlled wasting? Do you have a proposed formula for hole spacing for a given area? Do you stir or level out your substrate at any time to insure even flow? And lastly, Would you say that your skimmer has increased output, decreased output, or stayed about the same as before the cpw system was implemented?

Thank you for your time.
 
darrellh said:
Hi ldrhawke,

Can you give us un update on how the nitrate measurements in your water column are doing? Are you now feeding as much as you were before adding CPW to your tank?

Thanks,
D

Nitrates are still zero, but phosphates are up to .1 since I went back onto heavier fish feeding. I am using phosphate reducing chemical RowaPhos and polyfilter to try to get them back down. I have too many fish for a 60g reef system so it may be a continuing problem and need chemicals or polyfilter media to keep phosphate down.

I use the polyfilter because I am concerned about the quality of the tap water, and copper content, even after going though RO/DI and carbon filters. Florida is has a ground potential problem and copper from the plumbing system is common.
 
Back
Top