Closed loop

[puffer]

Can any one give me some pointers is doing a closed loop.

[reefrunner69]

What are you looking to do with the closed loop and what size pump are you going to use?

[puffer]

reefrunner... I want to set on 2 closed loops one that runs down the inside of the tank with 3 water outlets and one that runs under the sand with elbow outlets the pumps are ocean runners 3000's.

[reefrunner69]

and one that runs under the sand with elbow outlets

What would be the purpose of this? You would loose all the denitirfication properties of the sand. By running a closed loop under the sand, it would constantly oxygenate the sand bed and would not allow the anoxic regions required for denitrification.

[Anemoneman]

I wonder if Puffer is talking about simply hiding the plumbing under the sand and providing a lateral flow across the surface with the elbows, not actually aerating the sand bed like a reverse flow UGF - that would be a disaster.
I don't think water circulation has to be that fancy though. A couple powerheads or a sumpless overflow (short circuited with a return pump) would work better.

[reefrunner69]

a sumpless overflow (short circuited with a return pump) would work better.

That's pretty much a simple description of a closed loop, accept you would not use an overflow, you would use a direct siphon to the pump.

[loganj]

The only advantage I can see to this might be less heat being introduced to the tank because the pump is external. As you know, most external pumps have air cooled motors. I am going to use a closed loop on the 180 when I set it up. Not because of heat problems, but because I have a Little Giant pump that is large enough and I didn't see any other use for it. I have been told that this is one disadvantage to the Mag Drives...they leach more heat into the water than Little Giants, Iwakis, ect... Even if they are run externally. It would also be an advantage on a nano tank since PH's take up lots of room in a small tank. Check out www.vatoelvis.com for plans for the buried plumbing.
Logan J

[Anemoneman]

Is this the link you were referring too?
http://www.cichlid-forum.com/articles/ug_jets.php

[reefrunner69]

The only advantage I can see to this might be less heat being introduced to the tank because the pump is external.

There are a couple more advantages to a closed loop, one being the flexibility of water movement . With The Flex PVC and all the other fittings available, you can litterally have a dozen different ways to move water in the tank via one external pump. Where with powerheads...there are but a few. The other advantage is asthetics. A few returns coming over the side of the tank vs 3 to 4 phs....

[loganj]

Mark,
Yeah, I guess it is...I hadn't been to that site in so long I didn't realize they had moved .
Logan J

[puffer]

Anemoneman... you are correct use the sand to hide the pipe work, So are we saying that closed loops are a good idea.

[loganj]

If you have the pump already, there's certainly no reason not to. If it was between buying a $100.00 pump to do the closed loop or buying a couple of $20.00 power heads, I'd go with the PH's. The closed loop will work just fine though.
Logan J

[reefrunner69]

So are we saying that closed loops are a good idea.

Yes, closed loops are a good idea, but as logan said, there are alternatives. I personally feel that a closed loop is more versatile and offers options that aren't available with phs, but are easily available with a sump type system. What it is going to come down to is preference and budget.

[roadster3043]

Greetings.

Any recommendations for a 10 gal nano(pump size, etc.)?
The PHs that I have occupy most of the tank's rear.


TIA

[reefrunner69]

I would use a Mag 5 or the next smaller one (3.5 I think) and plumb it straight up to a manifold with 4 returns for the tank. I would plumb in ball or gate valves for each return so you can control the flow.

[loganj]

I'm using a Maxi Jet 1200 for a return pump on the two 20 gallon coral tanks. It creates a good current and handles the 3' or so of head just fine. It's running submersed in the lower tank though. The manufac claims the Maxi Jet will run externally, but I'm not sure I'd trust the seals on it for any amount of time. The Mag 3.5 should do a fine job as long as you use the manifold to split up the return as reefrunner suggested. One return would be too much current in one place. When I had my 10 going, I had about 300 gph going through it via 3 MJ 400's (106 gph) and everything did great.
Logan J

[Hara]

ball valves, gate valves !>!?!?! where does one figure out what these things are when they dont have a clue?

[reefrunner69]

Ball valve



Gate valve

[Anemoneman]

An internet search
A ball valve uses a ball with a hole in it to shut off flow. A gate valve is like your hose faucet. It uses a little door or gate to shut off flow. A ball valve requires 1/4 turn to shut off. A gate valve requires many turns to shut off and may be a better choice for flow control.