RDSB

[stifrk]

Ok so I had an idea and obviously it would scale to size of the tank, BUT what about using like a 12" piece of PVC about 1.5' in length, capped at the bottom for a base.  Basically drill a holl in the side and glue in the line from the pump so that it swirls water around the sand and eventually over flows the top of the PVC pipe.  This would be sitting right after a filter sock in a larger sump (again scale to size of tank/sump)  Seems like an easy way to get a little something extra.  Any pump size would work just put a T in the line with a valve on the open side to adjust how much pressure is being forced into the PVC pipe. 

Thoughts? Good, bad, dumb idea, or pointless because.... ?

[slandis3]

It's a good idea but most people either use 5g buckets or a new trash can. The buckets would be pretty easy to use. Drill some holes and install some uniseals and your set. Someone here used a trash can and used bulk heads.

[jd]

RDSBs are great for nitrate removal, but I wouldn't spend the money on a 12" section of PVC. A 5-gallon bucket with the handle removed works very well. An important thing to remember is that you want the cleanest water you can get to travel into the bucket. Any waste that can settle in the bucket will add to your nitrates.

[jd]

Beat me by 50 seconds Mike 

[stifrk]

ok so you would want to put it last right before the return pump.  I am trying to come up with a way to integrate it into a sump setup is the thing. 

I am pricing acrylic to make a 48x24x15 tank and not even sure how to figure out the math on the gallons that it will hold.  I just want something not too deep and mainly for corals.  Fish are nice but eventually I want to get a 125 for fish.  Also I am going to make a sump with almost the same dimensions just 40x20x20 or something like that to go under the tank.  Then I want to make a display fug to go on top of the tank.  Not sure on the size of the fug I will make but I want to make a full display unit almost like an entertainment center for the back wall of my living room.  My son liked my fug I had for my 65 and wanted to make one with gravity flow back into the tank this time.  Last time I had it down with my sump under the tank.

How do I figure out the gallons a tank will hold and also what thickness I need to get.  3/4" sheet of 48x96 is $655 but I have only checked out one place so far.  Looking at tanks online with similar dimensions... they are more expensive and that doesnt include bulkheads or overflows.

[rayk]

That is 75 gallon tank, according to calculator on ReefCentral.com. 

- rayk

[HUNGER]

thats a good idea

[stifrk]

do I need 3/4" or will 1/2" work, HUGE price diff lol.  Also if I upped the size to 48x24x18 it puts it at basically 90 gallons.  Can i do a 90 gallon on 1/2" acrylic?

I dont want it to bow so will do euro bracing but if I do the 90 gallon with 3/4" i will need more than one sheet. 

oh and because of blade thickness it wont be true to exact size.  48x23.5x15 but you get my drift.

[JoeAyers]

1/2" will be plenty. my 300 96x24x30 was 1/2" with eurobracing and only had a slight bow. And Honestly 3/8th would be enough if it is only 15" high. My old sump was 45x24x16 and it was 3/8ths with no bow even when full. It was eurobraced.

[stifrk]

oh wow ok well that changes things drastically price wise to go down to 3/8".  back to the topic, RDSB is there a way effectively to include it into the sump and if so could someone explain it?

The stand will be 30" from floor to where the main tank will sit.  A 5g bucket not sure will fit sitting ontop of the sump.  I dont want to make the sump too shallow because i want tohave LR in it in the "traditional" area that most people put a fuge in a sump.  The only difference is that I want the water to flow UP through the LR and overflow into the skimmer area and then to the bubble trap before hitting the return.  Not sure if I am going to use a sump style return or external pump.  Again getting off topic but trying to figure out how to run a RDSB or "really deep sand bed" as I like to call it lol.

[HUNGER]

i used 1/2 my sump is 68x19x19

[JoeAyers]

You can see my sump in this pic. I just used the center section as a deep sand bed. I didn't use any macro though and just kept the area under the stand completely dark. All water entering the sump either went through filter socks or directly to the skimmer so it was clean when it passed over the sand. In about a year there was never any build up on top of the sand.

[stifrk]

Ok maybe I have the wrong idea of what a RDSB is.  I thought the point of it was to have water flow THROUGH it and not OVER it.  Does it make a difference to just have flow going over? I have heard that it causes pockets of live sand to die which in turn causes ammonia spikes.  My goal was to have a pump inside the sump after the filter socks to pump water into the bottom of PVC or a bucket, up through the sand and then just overflow the rim of the PVC or bucket into the sump.

Am I off in my thinking?  I really have no clue about them and was told a few years ago that a RDSB was the way to go.

[JoeAyers]

Purpose of an RDSB is to have the water flow over it just fast enough so particles do not settle, thus creating an area of bacteria at the bottom of the sand that consumes nitrates. As long as you keep the top of the sand clean you should not have the issues that some people have with DSBs in their tanks.

Flowing the water through it will make the sand act more like your live rock with bacteria that eats the nitrites. They work well when they are operational, but if the power fails and you don't keep the water moving through them the bacteria dies very quickly and when the power comes back on and pumps water through the sand filter it adds all the nasties back into your tank.

[lazylivin]

Ok maybe I have the wrong idea of what a RDSB is.  I thought the point of it was to have water flow THROUGH it and not OVER it.  Does it make a difference to just have flow going over? I have heard that it causes pockets of live sand to die which in turn causes ammonia spikes.  My goal was to have a pump inside the sump after the filter socks to pump water into the bottom of PVC or a bucket, up through the sand and then just overflow the rim of the PVC or bucket into the sump.

Am I off in my thinking?  I really have no clue about them and was told a few years ago that a RDSB was the way to go.

What you are describing is a fluidized sand filter. That is much different and is more often used in FO tanks and swimming pools. The objective of RDSB is to reduce the amount of oxgen in the sand and a fluidized sand filter is to increase oxygen in the sand. Hope that helps

[jd]

You're thinking of a fluidized sand bed. Those also work to remove nitrates but have some problems if they are ever shut off due to the bacterial colony collapsing.

EDIT: Both Joe and Brian beat me to it....

[stifrk]

Gotcha! Thanks so much for clearing that up.  Ok so using your sump as an example (which i really like the design of btw), would it help to have an area that I have water flowing up through LF sitting on an egg crate shelf (or acrylic with holes drilled) and then into the skimmer area before hitting bubble trap?

I wish I was good at making designs on the computer so i could show you what is in my head.

filtersock->RDSB->baffle water to under LF and up through it->skimmer area->bubble traps 1-2" apart->return area

Thats whats in my head in the rough sense of design.

[stifrk]

LOL I really do feel like a noob and am very thankful for all the explainations from EVERYONE.

I think I feel a beer/brat tank/sump building party this summer

I am currently experimenting with bending 1/2" acrylic.  I would love to be able to make a U in the broad sense for the main part of the sump.  If that goes well I want to see what I can do about doing the the front and 2 sides as 1 piece for my tank.

DONT use MAPP gas lol, just melts it pretty much uncontrollably, scorches it very easily.  So yeah using propane and its going ok so far, I only have a few small sample pieces of the 1/2" so the real test is when I get in a larger sheet and can try it out.  I am going to make a bending frame to help hold the tank/sump.  I also think it would be better to get one of those torches they use to burn weeds with and attach it to a propane tank like for cooking and use it that way. It has a much larger and broader flame, rather than a small pinpoint flame.

[HUNGER]

im in i heard beer and brats

[janey]

To JD
important thing to remember is that you want the cleanest water you can get to travel into the bucket.


 and where do i place water coming out of bucket ??

 back into socks , back into tank ?

thnaks

Janey

[cyberwollf]

To JD
important thing to remember is that you want the cleanest water you can get to travel into the bucket.


 and where do i place water coming out of bucket ??

 back into socks , back into tank ?

thnaks

Janey

Either is fine, shouldnt have any debris in the water.