Plumbing my 40G breeder to a 20G sump - Advice Please

GuildedGravity

New Member
Hello all,

I have never plumbed a tank before and was looking for some friendly input. I have done some research but the more input the better. This is my situation:

I have a 40G breeder and a 20G sump that I built. I have a Fluval SP4 pump which I realize now is way overkill. I figure I can use it if I upgrade in the future though and for now I will put a gate valve to regulate the flow. I was thinking of drilling 2 holes in the tank. One 1.5" bulkhead hole for a Eclipse M Overflow Box (800 GPH) to set up a Herbie overflow (2X 1" bulkheads in the external weir). Then a 1" bulkhead hole on the opposite corner for a return (also considering an over the top return without drilling a hole). I want to shoot for around 600 GPH. For reference at my head height of about 3.5' the SP4 says it does ~1213 GPS with nothing factored in for bends, valves, or couplings.

I attached an image of what I am thinking. Sorry for the crude drawing and poor handwriting.

Any help is appreciated. Thanks!
 

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PSU4ME

JoePa lives on!!!
Staff member
PREMIUM
I would think about a controllable return pump vs using the gate valve to throttle it, or get a right sized pump and manage it with the overflow. Def want the gate valve there.
 

DaveK

Well-Known Member
I agree with @PSU4ME in using a DC controllable pump. It's not the best idea to use valves to control output flow from a pump. Also a DC controllable pump will use a lot less energy, which means you save some money in electricity costs.

You may still wish to use valves though. I usually recommend true union ball valves. Here is one example (offsite link) - https://pvcpipesupplies.com/1-pvc-true-union-ball-valve-gray-epdm-socket-1410gs.html Note that there is a union on each side of the valve. This makes them ideal for use when you want to be able to take something apart for cleaning, maintenance, or replacement. I usually connect one directly yo the pump output. This lets you close the valve and then disconnect the pump, so you can remove it and clean it. Also you should need far fewer unions.

Here is a trick. Initially build this with the minimal number of unions, other than the ones that are part of a valve. Purchase a few extra unions. Then as you find you need an additional union you can cut your pipe there and add one. You likely use far fewer and also have them end up in the best locations.

On the use of gate valves, Gate valves are big bulky and expensive valves to deal with. Their advantage is that they give you a very precise control over the flow through them. So you only want to use them where you need this kind of control. On your overflow, I'd first try a true union ball valve, as mentioned above, and only go with a gate valve if you have serious problems controlling the flow.

I am assuming that the term "flex tube" means the usual clear vinyl tubing. This stuff usually is connected up using hose barbs. This works, but you get a reduced flow. Rather than use vinyl tubing, I recommend you use flexible PVC pipe, also know as spaflex. Here is an example (offsite link) - https://www.savko.com/collections/pipe-and-tubing/products/white-flexible-pvc-tubing This material is connectd up using the usual PVC pipe fittings. It's not as flexible clear vinyl, but you don't need hose barbs to connect it and it will not kink or grow algae inside it. This means that from your overflow box you can runs a straight single run of pipe to your sump, no transitions needed. Same thing on the return pump side. I generally prefer to use rigid PVC pipe when possible, but use flexible PVC pipe with I need to get around something or need a gradual curve in the pipe.

Some notes -

You might have some trouble finding true union ball valves, and flexible PVC pipe locally. The internet is you friend here. Shop around because prices can vary greatly.

Make sure you have some method in place to prevent back siphoning on the return if power fails, and be sure to test it regularly. Otherwise it's very easy to have a flood. A check valve is one way to do it, another is to drill a small hole in the return so air can get in to the pipe and break the siphon.
 
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