Another closed loop question . . .

[Jorsan]

After been reading all the links post about this matter and because there are some black areas of this matter in my brain, I think is better to ask directly about my idea and hear your comments:

After some time having a beautifull 150G, I had to downsizing my reef. and now I have a AGA 55G regular. Because I have so small space now, I want to go with closed loop for water movement (the great "Tunze streams" time has gone now for me). Beacuse of this, and because I love lots of turbulency in my tank, decide to buy a powerfull secuence dart pump . Well, here is where I need some answers:
1.- first of all I understand -after reading a lot- that if I have a 2" inlet thats exactly what I have to mantain as an inlet in my tank, but one question here: as you can imagine, I can't have an open pipe in the water because everything that moves about 4-5 inches will be sucked by it so, what is the best strainer that I can built/buy for not restrict the inflow? maybe better use a "T" and add another strainer in the tank?, I know this is a critical part to get the most of a pump .

2.- About the outlet, I want to go with a rectangular mainfold of PVC in the top of my tank, no devices that open and close the circuit, just plain vanilla. Here I need your experience: first, the outlet of the dart is 1.5" so is my understanding that I have to mantain the same diameter in all the circuit (am I correct?) but, what about the nozzles diameter and how many of them can I use to have a powerfull flow that can make random courrents?, one idea could be to add 8/10 nozzles with the posibility to close any of them, this way I can decide what, how much, and where to have flow.

3.- About the outlet also, could I use a "T" and have two circuits, one on top and one on the bottom to move all the detritus? maybe two outlets in the bottom and 4 in the top?

Any ideas will be VERY apreciated. Thanks

[Anthony Calfo]

cheers, Jorsan

Understood my friend. The 55 gall is rather narrow indeed. Having a thick manifold pipe will critically reduce the already narrow working space at the top of the tank (only 13" wide as I recall... to then lose 3-4" of that for a 1.5 or 2" CL perimeter pipe - yikes!)

You may simply have to accept some compromise to total water flow here for using a smaller diameter pipe.

As for the feed/flood to the pump(inlet) - yes... please do maintain the pumps fitting size (2" here?). And keep the pump as close to the drilled tank bulkhead as possible with little or no impedance (straight feed is best... avoid elbows or long runs)

As for the outlet off the pump... why don't you run 1.5" to the top of the tank and then step down to 1" for the manifold? This is what I have done for my 120 gall with a Hammerhead. The flow is good. I am sure it would be better if my manifold was larger... but I just wasn't willing to give up the extra working space.

As for the tees... do come off with more than you need and cap them as necessary. At least 6 running strong would be nice. Having say 8-12 on hand would be ideal for this tank IMO.

As for the second lower loop... I dunno. never tried it. It sounds unnecessary and complicated/unsightly IMO. Its not needed for flow down low as adequate flow at the top blasting down with displace water, etc.

But if it appeals to you... do experiment in a laundry or bath tub. The PVC is cheap enough... and the couplings to extend/retrofit it full scale sized later are mere pennies.

Let us know how it goes either way

kindly,

Anthony

[Jorsan]

Thanks for your response Anthony and you gave me great ideas here that Im gonna work.
Let me clarify something that I forgot to metion before: my tank is not drilled (and Im not using a sump), I need to figure out how can I design an inlet INSIDE my tank and keep safe all my animals. One idea was to run a perforated 2" PVC pipe along the back wall (maybe 3 feet long) at 2-3 inches below water level (something like this: http://www.aquaticeco.com/index.cfm/.../iid/8564/cid/) . Maybe this way, even when I will need to use two or three elbows (I'll try to use 45 angle not 90), can get what I want. Please, if you have a better idea or you consider to drill the tank and design something different, please let me know because this is the time for do it.
One question that remains anunswered is if you consider correct to use -in the mainfold- the diameter of the Tees same as the mainfold itself or maybe, because I'll use several outputs, is better reduce them by half and inch and get more "push".
About your recomendation of reduce te diameter of the mainfold I dont think will be necesary because I have a canopy that covers all the surrounds of the top of my tank and having a rectangle of 1" or 1.5" makes no difference and nobody cant see it anyway.

Sorry for so many questions and thanks in advance.

[Anthony Calfo]

no worries... happy to help

As for the pump feed... alas, this is not an option: the tank must be drilled if you are going to use the sequence pump. External pumps must be "flooded" (water flows freely into them directly).

Forcing them to draw up over the top of the tank via a siphon is not only bad plumbing (future complications with power interruptions, etc)... but above all... it will starve the pump for water flow and cause dreadful noise/cavitation.

If you cannot drill the tank, you then need a submersible pump (like a Mag drive) to feed the CL. Along with that come some (small) heat issues.

[Jorsan]

A 55 tank (48wx12dx24h)is my only option. An overflow inside the tank will look terrible and that goes against my idea of a tank as clean as possible so, maybe an external overflow?, look, is not a big issue if I have to build a new tank (by the way want to do it with starphire glass) but always with this dimensions. I dont like/trust in the normal canister overflows in the market for all their problems so I consider that I have two options here, one is design an overflow like the one that you show in your book ; other option could be to design an external overflow in the same way that the internal ones (all the way from top to bottom but in the outside, not inside). To let the water go to there, I can lower the back glass of the tank for about 2-3 inches in the part where the overflow will goand that could let lots of water to go the the overflow directly. This overflow could have 4 " deep and in there I can drill a 2" hole that will go direclty to the pump (I could use a sump ONLY if it is necesary but I supposse the that water could flow directy to the pump). What do you think about this ideas? do you think this desing could carry all the flow that the pump will need?, wich design do you consider the less noisy? (noise is another BIG issue in my home)
Thanks again

[Jorsan]

what about an idea like the one that appears in the top right of this page?:
http://www.wetwebmedia.com/overfloboxfaqs.htm
Instead of having the oveflow box inside will be in the outside. How noisy is this design?

[Anthony Calfo]

I think you are missing the point here, my friend re: the mention of the overflow.

You do not need to have an internal CL pump in an overflow tray or tower. The submersible (mag drive, eg) pump can simply sit anywhere you can hide it in the tank... on the floor or higher up, behind some rocks or in a corner. Whatever you prefer. Is it unnatural to look at? Yes. Is it better than 4-6 internal powerheads? Yes again

If you do build/buy a new tank BTW... do consider a 50 gall breeder instead of the standard 55 gall tank. A 50 breeder is one of the best working shapes for a smaller reef display at 36 x 18 x 18

[Jorsan]

Thanks Anthony