Need approval for my CLS

Bayls

Not often called Junior!
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Hi guys
Before I go any further with building my CLS I thought I'd better get sign off from the pro's!
Summary - 650 litres in total, fed from a sump. I want to build a reef tank. I plan to have 12,000lph coming into the CLS which will run around the top of the tank on top of the reinforcing braces (tank is not drilled for any returns, only the overflow).
To explain the diagram (top view): I have an overflow with 2 durso standpipes and a backup standpipe all ending up in the sump.
At both sides of the overflow box I will allow space for powerheads to be positioned if necessary. To start with I plan for none.
I currently plan to have 7 returns all with Flexible Ball-Socket Joint Tubing to be able to direct the flow. This can of course be more. Piping will be at least 1".
My question is firstly whether this looks OK, and secondly whether it is OK to have all of the water flow directed from the top of the tank, or do I need to run some pipes down to the bottom to have some movement from the bottom/middle of the tank?
Comments/criticism will be much appreciated!
4934773c620e3ebf.jpg
 
Hi guys
Before I go any further with building my CLS I thought I'd better get sign off from the pro's!

Just to make sure that we all understand what we're talking about, a CLS is a Closed Loop System. If you're pumping the water from the sump it is not technically a CLS... but that's neither here nor there :)

Summary - 650 litres in total, fed from a sump. I want to build a reef tank. I plan to have 12,000lph coming into the CLS which will run around the top of the tank on top of the reinforcing braces (tank is not drilled for any returns, only the overflow)...

... I currently plan to have 7 returns all with Flexible Ball-Socket Joint Tubing to be able to direct the flow. This can of course be more. Piping will be at least 1".
My question is firstly whether this looks OK, and secondly whether it is OK to have all of the water flow directed from the top of the tank, or do I need to run some pipes down to the bottom to have some movement from the bottom/middle of the tank?

This is technically called a Calfo manifold, and it is what I'm using very successfully on my tank :thumbup:, so I would say "Yes, it looks OK..."

It will be better to have some water flow directed from the bottom half of the tank, but this should be easy to do with your extra power heads.

You could run some piping down to the tank bottom, but it will probably not look nice coming over the side of the tank, and you will have to drill a large enough hole directly above the water line to prevent back-siphoning when the power goes out (actually, you will have to do this in any case if your flexible tubing ends below the water level.)

Hennie
 
you will have to drill a large enough hole directly above the water line to prevent back-siphoning when the power goes out (actually, you will have to do this in any case if your flexible tubing ends below the water level.)

Hennie

Hennie, sorry, can you elaborate a bit on this, I am not with you? How will this stop the back-siphoning?
 
As you will be pumping water from your sump and the nozzles will be under water when you loose power the tank will be drained to the point that the nozzles will get air. So what they do is drill a hole in the pipe at water level so that it will suck air if the return pump is switched off, thus braking the siphoning.
 
I would have to agree, if you don't it may push most of the water thru the nozzle closest to the suply pipe.

Good point. I overcame this problem by using smaller diameter pipe fittings close to the supply, and larger diameter fittings further away. Even so, the amount of water flowing from each opening is not even, but that's actually better for the creation of "chaotic" flow.

Here's what mine looked like three years ago when I started my current tank (smaller pump, and running it through a "wave maker" which restricted water flow even more) - today it's delivering about double the flow you see in the photo...



Here's another, slightly more close-up...



Hennie
 
You may find 12000L ph through the sump a bit fast on this size system i would go for the proper closed loop with another return pump to feed water from the sump. JMO.
 
You may find 12000L ph through the sump a bit fast on this size system

Agreed, Alan, but if it's a 12 000l/h "no-head" figure (as I suspect it is...), the elevation from sump to tank, and the number of elbows in the line, will probably halve the actual flow rate...
 
Thanks guys. I will split the line, that makes sense. I'll just increase the outlets to an even number then. The hole to prevent siphoning also makes sense! No point in irritating the wife any more than she already is!!
 
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