Undertank Filtration Components

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Rudy

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Dec 3, 2002
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Hi! I have been running a 55g FOWLR tank for 10 years with cannister filter, biowheels, etc. I purchased a 125g and recently had 1" diameter holes drilled out the top back panel for draining to filtration, sump, etc, below the tank (inside stand).

I intend to make my own sump, and w/d if needed, and have good plans to do so. What I am wondering about is what is the best type of pipe/tubing to use to accomplish the proper flow of H2O from tank to under tank equipment? Along that same line, what type and where should the valves be located to ensure no backflow and/or overflow from the return?

Thanks for the advice/ideas.
 
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Guy W

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Apr 8, 2002
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A lot of people use PVC for the drains and returns, either Ridgid or Flexible. Since you are going DIY I'd get a glass tank for the sump, run PVC from the tank drains down to it, then drill out a hole in the side of that, run a flexible hose from the bulkhead in the hole to the pump, then run PVC from the pump to the tank.

Mostly you will probably only want a ball or gate valve after the pump outlet, or if the pump will T off to more than 1 return a 2 valves after the T, so you can control the flow to each return if needed.

Also, I really like closed loop circulation pumps, instead of powerheads hanging in the tank.

For this just drill 1 hole in the back of your tank, run PVC down to a 2nd pump (not your pump on the sump), then run PVC from the pump back up to the tank, either in holes on the back of the tank or over the back side of the tank. You can put valves before the flow goes back to the tank to control it as well.

Depending on if your skimmer will be in the sump or external you may need to drill a 2nd hole in the sump, for the skimmer pump. If the skimmer will sit in the sump it doesn't matter.

Guy
 

Rudy

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Well I reposted on the Gen Marine portion of the forum and although the thread had 45 viewings it received no new opinions/posts. I surmise either nobody knows or noone cares. Such is life. :p

Nevertheless, here is an additional question(s). How, if at all, do I regulate the flow of water out the back tank holes heading down to W/D, sump, etc? Is it based soley on the water level in the tank?

I am admittedly confused :confused: on this part of the enitre project. I can visualize the entire mechanical set-up but the physics of the water flow concerns me. Of course it is very important to get right. :D

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Cheers, Rudy
 

Guy W

AC Members
Apr 8, 2002
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Naples, FL
Originally posted by Rudy
Well I reposted on the Gen Marine portion of the forum and although the thread had 45 viewings it received no new opinions/posts. I surmise either nobody knows or noone cares. Such is life. :p

Nevertheless, here is an additional question(s). How, if at all, do I regulate the flow of water out the back tank holes heading down to W/D, sump, etc? Is it based soley on the water level in the tank?

I am admittedly confused :confused: on this part of the enitre project. I can visualize the entire mechanical set-up but the physics of the water flow concerns me. Of course it is very important to get right. :D

__________________
Cheers, Rudy
Are the drains from the tank to the W/D going to be on the back of the tank or on the bottom of the tank? It doesn't really matter I'm just curious. It's better to have them on the bottom because that builds up more pressure and will get you higher flow rates.

But, how to regulate the flow.

You don't really :)

If for example the holes are on the bottom of the tank, you would have an overflow box in the corner, which is just an Acrylic square from the bottom of the tank to the top, and it has teeth or slots cut out at the top. The water over flows into the compartment which has the holes. YOu would then have a PVC stand pipe go from the hole to almost the top of the over flow box. If the power goes out the water will drain down that pipe to the W/D utnil the water level goes lower than the stand pipe. That doesn't really regulate the flow, it regulates the water level in the tank.

So really the only way to regulate the amount of gallons per hour that go down the hole is the size of the hole. For example a 1" hole flows about 600 gallons per hour. So if you want more, make 2 drains, or bigger holes, and so on.

You don't want to put a valve on the drain because that makes it more likely to get clogged, and if it gets clogged your screwed... water all over the floor!!!

So what you do is figure about how much flow will drain based on the size of the holes and get a pump that will match it or be stronger and restrict the pump with a valve if it's too strong.

However... A sponge prefilter on the overflow pipe will slow it down a bit, and it will get slower and slower as it gets more and more clogged. :( :(

Don't worry about how fast it's draining to the Wet Dry. Just make sure your pump is strong enough to handle the return. And make sure that the water level in the sump is low enough to accomadate the pump turning off and the water from the tank draining down to the overflow level and filling the sump/wet dry. It probably sounds more complicated than it is. Really it's not.

Hope that was some help.

Guy
 

Rudy

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Dec 3, 2002
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Holes are on back of tank about 5" from top. Could drill bottom of tank due to tempered glass.
 

Guy W

AC Members
Apr 8, 2002
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Originally posted by Rudy
Holes are on back of tank about 5" from top. Could drill bottom of tank due to tempered glass.
Thats ok, you would do the same priciple. Put an overflow box in the back of the tank to enclose the hole. Then just run a PCV Pipe up to the top of the overflow box to where you want the lowest point/water level. You will use a 90 degree elbow instead of being able to go straight up and all 90 degree turns slow down the water flow a bit. I don't know how much exactly.

Guy
 
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