I really need some help in the GPH department please!

[Myers13]

Hello everyone,
I need some advice about this build. I thought I was finished and things were going well, but now I'm thinking I missed something somewhere. This is my first sump so I'm sure I've made some mistakes, I just need to know how to correct them. I got the tank, stand and canopy for free and the tank wasn't drilled so I thought I'd go the overflow box route. Possibly mistake number 1, I'm sure opinions vary. After reading more in depth about flow rates and head pressure loss, I'm thinking I need a bigger pump and overflow box, and maybe even sump, but a bigger sump isn't an option with the current space I have available.

Anyways, I'll see what everyone has to say and go from there. Here's my tank as of now:

90 gallon non drilled tank

Aqueon Proflex Modular Sump Model 3
- Set up Refugium Style
- Rated for tanks up to 125 gallons
- Rated at up to 1625 GPH
- Return chamber is 8 1/2" x 13"
- Single 1" inlet

- Aqueon 4000 Submersible Pump
- 755 GPH
-12' Head Loss
- 3/4" Outlet

Eshoops PF800 Overflow Box
- 800 GPH
- Single Drain line
- Rated for tanks up to 125 gallons

Coralife Superskimmer 125
- 500 GPH
- In Sump or HOT

Return line
- 3' of 3/4" Clear Tubing
- 1 Check valve
- Loc Line w/ "Y" reducer to two 1/2" lines w/ flares

- Coralife Mini T5HO Refugium Light

- 2 Hydor Koralia Evo 1050
- Ocean Pulse Duo WaveMaker

- Autoaqua Smart ATO System

- OR IT2080 LED lighting

I have realized a couple errors that I've made and a few places to tighten up the loop such as:

- I need to re do the return line: I used clear tubing and the area behind the tank gets just enough natural light to grow algae and slow down the speed of water. I'll be switching out to either black vinyl tubing or Flex PVC.
- I crossed the lines instead of going straight up and down to the return and drain. I can rearrange them and gain over a foot on each one.
- Following someone's advice I plumbed a check valve onto the drain line right before the inlet to the Sump. I'll remove that to regain flow some flow loss.
- I think there's enough space behind the sump to take out the skimmer and hang it on the back for additional return chamber volume, if I absolutely have to
.
- Even though I went with the manufacturer's recommendation and got the Aqueon 4000 submersible return pump, I now know that with all the variables of flow loss, I need a larger pump, but I don't have this one opened up all the way utilizing it's full GPH. Also, I'm not sure if I can find one that will fit in the return chamber, but if not, this is an option I found in the sump manual:

"As an alternative to a submersible pump the wall of chamber 3 can be drilled with a standard hole-saw bit to accommodate a bulkhead fitting (not included) for use with an external pump. A 1" bulkhead requires a 1 ¾" hole-saw bit."

What I do not understand is:

The Overflow Box is rated for up to 800 GPH, and the return pump is rated for 755 GPH (before head loss from 3' of vertical plumbing, a check valve, and two 90° PVC elbows,) why do I have to use the check valve to impede the flow of the return pump before it drains the return chamber?

I was told I need a bigger pump, but I couldn't get one because the return chamber was too small. Why would I need a bigger pump if I have to turn this one down? My overflow box is wide open, so how can I get more drain flow out of it to open up the return pump all the way?

Also, the return pump and skimmer pump need to be around 2" - 3" from the surface, so if I do keep more water height in that chamber, am I supposed to put the pumps on some kind of platform to raise them up?

Last night I moved my inside portion of overflow box down into the water further and that seemed to increase drain speed, but not enough to open the return line check valve very much more, and the box is only about 1/4" above the water surface. I'm sure this is probably too far down, so I'm moving out back up.

All in all, I don't understand how to get more GPH out of a sump that is rated for up to 1625 GPH, an overflow box that's rated for 800 GPH, and a return pump that's rated for 755 GPH (and is only getting around 450 GPH after subtracting head loss and flow restrictions from plumbing parts) but has to be reduced or will drain the return chamber!

I'd appreciate any help or advice anyone can give me. If I had more space under my stand I would've went with a larger sump however, I only had a total length of 25" and the Proflex model 3 is 25 1/2" long and is rated for tanks up to 110 gallons. I'm stumped lol. Thanks -Mike

[jimsflies]

Lots of info there! So here is a long response back. :)

First, I would never use a check valve on a reef tank. Here's why: they will not properly seat when needed because growth in the lines will occur regardless of whether they have light or not. Sponges will eventually grown in them, bacterial mats will form, its inevitable and a check valve will not perform when needed.

I'm unclear why you have a check valve? A check valve is often used to prevent unwanted flow from the display tank into the sump when the power is off or the pump is shut off. This is a bandaid to prevent floods and dropping the water level too low in the display tank due to back feeding into the sump. Typically I see people try to use check valves on return lines because they haven't designed the system correctly. A correctly designed system should have an air gap/siphon break so that when the power goes off a siphon does not form that overflows your sump. Also some water siphoning back to the sump is unavoidable so there needs to be enough freeboard in the sump to accommodate it. I would argue this is the most important design parameter of a sump. Water on the floor is dangerous, and also can result in problems with your reef since when the power is restored, the pump could be running dry or an auto top off will kick on and lower the salinity of the tank by the amount of water on the floor.

Mike, were you at the swap helping me when we had the flood last weekend? That was caused because the power shut off on one of the vendors tanks and he didn't have a proper siphon break and it overflowed his sump (which was a 5 gallon pail). I think if you search for siphon break here on CR, you will find more info on how to achieve a siphon break.

As far as valving, I would never put a ball valve on the drain line. Valves are a restriction in the line even when they are open and could potentially plug if a fish or whatever flows into the pipe. A plugged drainline will result in a flood and possibly jeopardize your reef. The drain line should be a straight shot into the sump.

Flow rate should be controlled via the discharge side of the pump. I would put a tee on the discharge side of the pump with a valve on it to bleed any excess flow back into the sump. You might find that with new pumps and plumbing that you need more water throw this line than when the pump and piping are older. So its nice to have the valve so you can adjust over time.

As far as sizing of your return pump and sump, the controlling factor sounds like it is the overflow box. Flow through sumps are typically 5 times the volume of your display per hour. So for a 90 gallon, you should be looking at a flow rate of 450 gallons per hour. Also this should roughly match your skimmer's flow rate...so you are in the right ball park for sizing. I would say you have the right equipment for your sump and flow.

Keep in mind, the flow through your return line only makes up part of the flow required for a reef. Typically, 10-30 times an hour total flow in your reef is what you will want to keep everything happy. This is achieved with powerheads or closed loops.

Also I would avoid drilling your sump for external pump and try to keep your skimmer in sump if you can as well. That's mostly a personal preference, but I think having them all contained is safer and less likely to leak outside of the tank. For me, the number one design factor for a reef aquarium is that it doesn't leak or flood.

[Up2no6ood]

Maybe the overflow isn't achieving a syphon? I have seen people mod those overflow boxes with a derso standpipe that might help with flow. What diameter hose are you using for your overflow box? I would also stay away from flex tubing. All those ridges can trap air bubbles slowing the flow.

[MizTanks]

I use Flexi Tubing for my over flow and have no issues with trapped air slowing flow :)

[Up2no6ood]

I guess it depends on how many bends it has in it? Ive seen some setups take forever to clear the air out when a pump is turned off and back on

[schminksbro]

Lots of info there! So here is a long response back. :)

First, I would never use a check valve on a reef tank. Here's why: they will not properly seat when needed because growth in the lines will occur regardless of whether they have light or not. Sponges will eventually grown in them, bacterial mats will form, its inevitable and a check valve will not perform when needed.

I'm unclear why you have a check valve? A check valve is often used to prevent unwanted flow from the display tank into the sump when the power is off or the pump is shut off. This is a bandaid to prevent floods and dropping the water level too low in the display tank due to back feeding into the sump. Typically I see people try to use check valves on return lines because they haven't designed the system correctly. A correctly designed system should have an air gap/siphon break so that when the power goes off a siphon does not form that overflows your sump. Also some water siphoning back to the sump is unavoidable so there needs to be enough freeboard in the sump to accommodate it. I would argue this is the most important design parameter of a sump. Water on the floor is dangerous, and also can result in problems with your reef since when the power is restored, the pump could be running dry or an auto top off will kick on and lower the salinity of the tank by the amount of water on the floor.

Mike, were you at the swap helping me when we had the flood last weekend? That was caused because the power shut off on one of the vendors tanks and he didn't have a proper siphon break and it overflowed his sump (which was a 5 gallon pail). I think if you search for siphon break here on CR, you will find more info on how to achieve a siphon break.

As far as valving, I would never put a ball valve on the drain line. Valves are a restriction in the line even when they are open and could potentially plug if a fish or whatever flows into the pipe. A plugged drainline will result in a flood and possibly jeopardize your reef. The drain line should be a straight shot into the sump.

Flow rate should be controlled via the discharge side of the pump. I would put a tee on the discharge side of the pump with a valve on it to bleed any excess flow back into the sump. You might find that with new pumps and plumbing that you need more water throw this line than when the pump and piping are older. So its nice to have the valve so you can adjust over time.

As far as sizing of your return pump and sump, the controlling factor sounds like it is the overflow box. Flow through sumps are typically 5 times the volume of your display per hour. So for a 90 gallon, you should be looking at a flow rate of 450 gallons per hour. Also this should roughly match your skimmer's flow rate...so you are in the right ball park for sizing. I would say you have the right equipment for your sump and flow.

Keep in mind, the flow through your return line only makes up part of the flow required for a reef. Typically, 10-30 times an hour total flow in your reef is what you will want to keep everything happy. This is achieved with powerheads or closed loops.

Also I would avoid drilling your sump for external pump and try to keep your skimmer in sump if you can as well. That's mostly a personal preference, but I think having them all contained is safer and less likely to leak outside of the tank. For me, the number one design factor for a reef aquarium is that it doesn't leak or flood.

Great advice Jim. I would only add 2 things.
1. It is important to get all the air out of the u-tube on your overflow. When you syphon the start the hose needs to be up in the crown of the u-tube to suck out most of the air. If there is a tiny bit of air left you can jiggle the u-tube which breaks up the bubbles so that they flow out.
2.You never want your skimmer in the return chamber. You want your water level to be stable and the return chamber should be the only chamber that changes with evaporation.

[Myers13]

Thanks for the reply Jim! I wasn't around when the vendor overflowed, lol, I was at Reef Paradise grilling hot dogs for Andy. I guess my problem was I didn't realize you were supposed to add in the flow rate of your powerheads. When I add that to my math, it comes up perfect lol. I still have to replace the clear tubing on my return line and remove the check valve from the drain line. After that I'm good. I forgot to mention that I was using a siphon break on the return line also. I even got the mesh lids completed. The only thing I'm still not sure on is the height of my overflow box. I do have a complete siphon going with no airbubbles at all, I'm just not sure on how deep to set it.

Thanks again for your help!
P.S. My frags from the swap are doing great

9786
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[Myers13]

Great advice Jim. I would only add 2 things.
1. It is important to get all the air out of the u-tube on your overflow. When you syphon the start the hose needs to be up in the crown of the u-tube to suck out most of the air. If there is a tiny bit of air left you can jiggle the u-tube which breaks up the bubbles so that they flow out.
2.You never want your skimmer in the return chamber. You want your water level to be stable and the return chamber should be the only chamber that changes with evaporation.

Thanks Andy, I made sure all the air was out of the U tube. Also, with the space i have available I had to go with this sump, and it seems that the return chamber is the only one I have evaporation in, so it looks like I have it straightened out. At least until I upgrade my skimmer. I had to go with this one until I can get the "Good" one, lol. Like I told Jim, I still need to replace the clear tubing, but everything seems to be going well.
Thanks bro!

9789

[Myers13]

Thank you to everyone for your feedback and replies!

[jimsflies]

I'm not an expert on external overflows. But, as far as how deep I think that would depend on the water level you want in the tank and also the water level in the sump when the pump is off. In other words, be sure to test a power off scenario to make sure you don't have a flood.

Glad the frags are doing well. When they grow out, I'm always looking for more frags for the wheel to pass on to other reefers. :)

[Myers13]

That's exactly what I did. I adjusted it by doing a power off test. When I can afford it, I'm going to get some fragging supplies and hopefully attend a Frag seminar. I'd like to Frag some of my nuclear green or imploding green polyps. Not sure which they are now lol.
Thanks Jim!