sump question

I have been looking into making a sump for my 125 freshwater tank. At the moment it has one fx5 on it and thats it. I have an extra 55 and an extra 20 long that I could use for the purpose. My question comes into play with pvc overflows (dont want to drill) and the return pumps. I have pumps that seem way too powerfull for the job. The one I would like to use comes from a portacooler fan. It pumps water pretty fast out of a 5 gallon bucket so my question would be how would I figure out how to calculate how many overflows needed and what size pvc to use to keep up with the pump. This would be my first try at the sump idea and I figured I have the majority of the stuff I need just need some direction.

Talk to dan about this , from what he has told me that is what he does for a living.

As far as sump design is concerned there are a few things you have to choose right from the start.
What size sump do you want.
How often do you want to exchange water in the tank.
Most importantly is budget haha.

When looking for a pump first option is internal/external. Internals are great since you won't have to drill the sump. Next in line is water flow. This can get tricky since almost all pumps are advertised with 0 head flow rates. In other words how much the pump could do with no resistance. So in our use we have to take vertical and horizontal head into consideration. For most people that only means vertical since this won't be an elaborate reef setup.

If we know it is 4 feet from the pump to the output in our aquarium that means we have to look for flow rates of the pump at 4 feet(many pumps have charts). It is important to know because a pump that does 600 GPH at 0 head might only do 350 at 4 feet if the pump is fairly weak. Once we have found a pump that will give our desired flow the rest is pretty easy.
One note is that you can always go slightly bigger with the pump then needed. Most pumps you can limit their output with a valve place inline with the discharge side. Never limit the input to a pump.

As for the over flow boxes. Just pick up one that will flow roughly what the output of the pump will be. Even if the overflow is larger then required it will work fine. Mine is an eshopps 1000 rated for 900GPH drain and I believe the actually flow is more like 500-600. Sine it is gravity drain it works just fine.

As for pipe size. I went with the put diameter of the pump. My pump uses a 1 inch fitting and so I used 1 inch pipe. You don't want to restrict the flow in most cases so an efficient pipe layout is recommended. Use minimal turns and be short and to the point with piping. For the overflow, I just went with the bulkheads drain size. If you have two bulk heads it is best to run two separate drains back to your sump.

The next thing on the list was sump size. Surprisingly you don't need a huge sump for your everyday uses. The way I look at it the larger the sump the more total water volume you will have and that is a good thing in my book.
You want to make sure it will be able to house all the bio media you wish to add. Also if you wish to put heaters and other things in the sump make sure that with the media added you will still have enough room for all your equipment.

I can show you how I setup my sump. You can see it here https://usafishbox.forumotion.com/t7727-wet-dry-filter It is a really simple design and honestly was fun to build. It is way bigger then I need but is expandable and that is what I really wanted.

Good luck!

Thanks for the link striking. I definitly font want to drill this 55 so one of the two pumps will have to work. I have tested both with 5' hose attached in 5 gallon bucket and it pushes the water out fast. the portacool one is 5.0 A at 1/6 hp not sure on how many gph. The second one says it will pump 21.3 GPM. So that's somewhere in the 1200 range. I think my problem lies in slowing it down. Putting a gate valve would slow it down but is that gonna cut the life span down of the pump?

Very hard to say. It would depend on how much you need to restrict it. 1200 is pretty good but likely less at 4-5 feet. See if you can find a flow chart for it, to get an idea of what the output would be. I ended up running my pump into a spray bar. It restricts the flow a little but allows me to have full pump output without blasting water everywhere.

Well it is designed for a swamp fan and has a spray bar in the unit with bulk heads and a float. I got a brand new pump and nothing else. The only info I could find is 1200gph at 1'. I do not have a float so being able to adjust the output would be awesome so it will run continuously. The top of the tank is just above 4 foot.

Looking at similar pumps that put out 1200 at 1' my guess would be that at 4-5 feet between 800-1000 GPH. So if you used a valve to dial that back into the 700-800 GPH area I would think you would be right on for flow. It will be hard to tell until you put this to the test. Honestly if possible I would setup some kind of test for this and see if adding a valve really makes the motor sound like it is straining. (fill the 55 up with your water change then do a big w/c on the 75 and let the pump do the work for you. See how long it takes for you to fill the tank. Also keep in mind that actually volume of water inside is different then the size of the tank --a 75 gallon tank may only hold 65 gallons of water---) This way you get an idea of what you are working with. PVC is cheap and a valve is $4 so you could setup a simple test and see how the flow looks to you and go from there.
You may also find that the flow would be perfect even when it is that high if you use a full length spray bar. I used a 48 inch spray bar and drilled 1/4 inch holes in it. Works great for me!

Ok that was my plan. The fx5 has a 72" spray bar on it and I can redisign that to be shorter and run the sump for the other half. My question now lies in the pvc overflow..75" 325gph,1" 600gph, 1.25" 900gph and 1.5" 1300gph. Is this correct? I want to shoot for one overflow and I know restricting this will be a no,due to overflowing the tank.

http://www.fishchannel.com/fish-magazines/freshwater-and-marine-aquarium/july-2009/aquarium-bulkhead.aspx


It will be kind of hard to find the exact bulk head you are looking for at a decent price at least. I have seen a few large overflows that use a size greater then 1.5" but most of the time it it goes 3/4 (200 GPH), single 1", Double 1" Then finally dual 1.5" for a 1600 GPH.
The funny thing is that if you look at advertised flow rates vs actually findings you can see just how over rated some boxes are!
Now the overflow box design has a role to play in how fast things drain as well so we can't leave that out of the equation. Even knowing the maximum flow rates for a given diameter pipe won't mean the overflow will give you that. If I saw that an overflow did 100 GPH I would assume that it would likely do a little less (900ish just due to everyone advertising rounded off and "good" looking numbers)

All in all you can just a somewhat oversize box from the pump or dial the pump back to meet the limits of the box. The overflow will just drain at the rate the water is added to the tank. As long as they are not too far off you won't have to worry about it breaking siphon.

Well I built a pvc overflow that is really quiet. I think I'm gonna need two of them to keep up with the pump. It's a really nice design that I found off mfk. It is 1' inside 2' and works pretty well. I'm waiting on it to dry so I can fully test it.

Very cool. Be sure to take pictures! I am finishing up a DIY overflow box. I will be posting here in the next few days one I get the results in. It is currently drying on my bench. I hope it works because so far I have paid a total of $20 for solvent vice the 80 for a new overflow!

Here a few pics of the overflow
Intake

Top of drain

Bottom of drain

All pieces apart

Final product minus the plumbing to sump

Looks good. Cheap easy design for sure! Wonder why the intake side has to be so long. I have seen this setup before but always thought they could do with half the length on the intake side. Less visible stuff in the tank and should work just the same. Built in siphon break is really nice and I would imagine it would start back up just fine after a power loss.

Yeah I am going to shorten it sooner or later. It works just fine without losing syphon. I have it hooked up in the bathtub and a trash can . I have a video but it won't upload . I will get it up soon. I think I might use something other then that 55 now that I see all the possibilities there are.