Please help with plumbing and sump design

[apex003]

This will be my first attempt at a tank with a sump. I've read a lot about plumbing, but want to put some pics out there for critique to see if I'm making any mistakes. The system is two 40 breeders. Top will be SPS display (2 x 150W) and bottom will be for frag grow out (2 x 75W) on reverse light cycles. Here's a plumbing sketch:

Water flows into the 6 x 3" overflow and through the primary 3/4" drain which doesn't have the solid PVC. Gate valve controls flow rate to match pump (Eheim 1260). The other is a secondary drain. I've heard that this setup is absolutely silent.

My primary concern is that I've got the plumbing right and I'm not leaving any critical parts out.

Here's the sump:

Pretty standard, I think. My only concern is making sure that I've got enough room for overflow in an outage. How can I figure out what my water level should be in the sump?

I can answer questions as they arise, but that's the basics. Please help me get this right the first time!

 

[Macimage]

It looks good. To figure out how many gallons will backflow, you need to multiply the lowest point your returns are before they will intake air. In your diagram, lets say they are 6" down from the top of your upper tank. Multiply 6" x the length of your tank x the width and then divide by 231. This will give you the number of gallons that will backflow to the sump from the tank. Then you have to add a bit more for the water in the lines.

To calculate how much water space you need to leave in your sump, you basically so the same mathematics. ie if you are thinking of leaving the top 12" of your sump for overflow, muliply 12 x length of sump x width of sump and divide it all by 231. This figure would be how many gallons 12" in your sump can hold.

Joyce

 

[jdieck]

Remove the valve on the main drain, make the drains 1" dia at least and install a Durso stand pipe to silent it.

The pipe at the discharge of the pump and up to the Y make it of a larger diameter than the two pipes after the Y to help balance the flow trough both branches. 11/4" and 3/4" for the branches will do.

 

[apex003]

Thanks guys! Bump for more advice...

Joyce-
Great. Thanks! I'll do that math once I get my return high figured.

jdieck-
Is there a chart somewhere that says how much flow you get through a given diameter drain? I was told that 3/4" is plenty big for the flow I'd get from my 1260. The only reason I ask is that I have some size constraints for the drain. I had the overflow box made only 3" deep, so I need the smallest bulkhead that will accomodate my flow. I'll try to do what you said with the pump discharge line, but I've only found wye fittings that are 3/4" all around. Can a put a reducer at the main input the the wye fitting and still get the same effect?

 

[bues0022]

apex003 - the flow throught the 3/4" overflow will be the same whether you restrict it with a ball valve or use a durso. My current tank is a 58 oceanic with a durso overflow and return up through the overflow box. Just today I am going to be taking out the durso, removing the return pipe, and doing basically what you have there. Your design will accomplish two things: 1) absolutely and completely silent, 2) absolutely no microbubbles. You'll only probably get around 550gph with your pump. If at all possible, use a 1" bulkhead. It is a little risky using a 3/4".

Also, with the plumbing out of the wye, NO - do not put the reducer on the main input of the wye. Think of it this way....Flow through a pipe is equal to the velocity multiplied by the cross-sectional area: F = V*A. We can agree that the amout of flow going into the tank HAS to equal the amount of flow coming out of the pump. If the area decreases, the velocity has to increase to maintain the same flow. By putting the reducer on the main input of the wye, you increase flow just before it splits. It doesn't sound that bad, but by doing this you are adding back pressure to the pump and making it work harder and pump less. Always reduce diameter AFTER splitting. Also, if at all possible, try to have the velocity after each reduction slow down and not speed up. If the flow increases after the split, you basically are adding back pressure and reducing efficiency (in a perfect world velocity would be equal, but we are limited by the sizes of PVC we can get.

Use this simple formula for checking your velocities:

V1 (velocity out of pump) = GPH of pump *924 / [D1^2 (cross sectional area of pump outlet or original tube diameter)*pi]

so, V1=GPH*924/(D1^2*pi) pi = 3.14159

Then, assuming both sides of the outflow of the wye are the same (smaller diameter):

V2=V1/2*(D1^2/D2^2)

Hopefully velocities V1 and V1 are close to equal. Let me know if you need any help figuring out these equations.

 

[jdieck]

<a href=showthread.php?s=&postid=11768357#post11768357 target=_blank>Originally posted</a> by apex003
Thanks guys! Bump for more advice...

Joyce-
Great. Thanks! I'll do that math once I get my return high figured.

jdieck-
Is there a chart somewhere that says how much flow you get through a given diameter drain? I was told that 3/4" is plenty big for the flow I'd get from my 1260. The only reason I ask is that I have some size constraints for the drain. I had the overflow box made only 3" deep, so I need the smallest bulkhead that will accomodate my flow. I'll try to do what you said with the pump discharge line, but I've only found wye fittings that are 3/4" all around. Can a put a reducer at the main input the the wye fitting and still get the same effect?

Try finding a wye hwere the diameter is the diameter of the pipe from the pump to the split. it does not have to be a stright Y.

a3/4" drain will give you about 300 gph of flow as a drain with no much room for reduction due to algae or debris.
If you can not increase the diameter you might need to use both drains as operating ones rather than one as back up.
This calculator will help you determine the drain size for a particular flow.
http://reefcentral.com/calc/drain.php

 

[xraydoc]

"Pretty standard, I think. My only concern is making sure that I've got enough room for overflow in an outage. How can I figure out what my water level should be in the sump? "

You can eliminate that need if you wish by using check valves on your return lines. Just a thought.

 

[bues0022]

IMO, most check valves that are reasonably priced (i.e. HD, Lowes, Menards etc.) are prone to eventul failure. Salt water is a pretty tough environment for a che valve to work properly. It will spen most of its live full open, and when you finally need it to work- it may be "stuck" open by salt or other sediment buildup. Besides, if something can go wrong, it will. Might as well make your design bulletproof, so equipment failure won't put water on your floor.

 

[ctripi]

You will need to consider that the rs80 will have a pump outside of the skimmer as well as a drain pipe thereby increasing the 'foot-print' of the entire skimmer. My rs135 takes up the entire end of my 29g sump. Could you also modify the sump graphic so we can see the flow pattern. As it stands, I'm curious whether your current design is feasible.

 

[bues0022]

Good catch ctripi! I've been concerned with the overflow I didn't look critically at the sump. Generally speaking, it's good to feed clean water to your fuge so you don't have as much junk settling. Also, you'll have a lot of bubbles coming out of your skimmer, so its best to seperate your skimmer from your return a little bit. It makes for a less "sexy" sump, but a simple three compartment sump is the easiest and fairly efficient. Return into skimmer section -> fuge -> return.

 

[apex003]

Thanks all!

ctripi- I'll modify my diagram tonight and maybe add some side views, so you can see elevations. In my head it works, but that's why I'm here... bascially I'm imagining:
water flows into ~15" bubble tower, overflows into sump/frag area, then overflows through slotted overflow to the skimmer, water height is ~8-9" to the skimmer, which is controlled by the baffle height and the water level in the return pump section is controlled by a litermeter III topping off fresh water. Hope that makes sense, but I'll provide images later...

bues0022- Thanks for all the input. I wanted to do sump > skimmer > return so that the water is cleanest going directly to the return, since that will be SPS display. I thought by skimming first, you would pick up all the crap in the sump and send it to the display. I included the baffles to address the microbubbles, and I was told that you can dial in the RS80 to virtually eliminate them. Don't know if that's true, but the output will be farthest from the baffles, giving the bubbles time to rise and be eliminated by the baffles before going to the return.

jdieck- I'll look at the bigger drain size. Any idea of the approximate total diameter of a 1" bulkhead? Regarding the wye fitting, it seems that it would be impossible to have 1" coming from the pump and then constricting to 3/4" for the two returns without adding the additional head pressure that bues0022 described.

xraydoc- Thanks for the suggestion, but I've read exactly what bues0022 said: check valves can and will fail when you need them most.

 

[bues0022]

If you reduce down to 3/4" AFTER the wye, you'll be just fine. Just don't reduce down before you split the flow.

 

[jdieck]

<a href=showthread.php?s=&postid=11770267#post11770267 target=_blank>Originally posted</a> by apex003
Thanks all!

jdieck- I'll look at the bigger drain size. Any idea of the approximate total diameter of a 1" bulkhead? Regarding the wye fitting, it seems that it would be impossible to have 1" coming from the pump and then constricting to 3/4" for the two returns without adding the additional head pressure that bues0022 described.

I do not understand the comment on head pressure.
a 11/4" dia pipe has a larger sectional area than two 3/4" pipes so if you use 11/4" from pump to split and 3/4 from split to tank you shall be OK. Use a 11/4" Y (Which is not really a Y as one side is stright)
Regarding the bulkhead dimensions from Aquatic Eco Systems here are the dimensions for:

Heavy duty schedule 80 bulkheads:
http://www.aquaticeco.com/index.cfm/fuseaction/product.detail/iid/6862/cid/1869

Or light duty (Most used)
http://www.aquaticeco.com/index.cfm/fuseaction/product.detail/iid/6885/cid/1895

 

[apex003]

Sorry for the delay. Here's what I intend for the sump:

Front view:

Side view:

 

[apex003]

^

 

[apex003]

Any feedback on whether my sump design is feasible? ctripi had some concerns, but I'm not sure what they were. It looks workable to me, but I need some experienced feedback. Thanks!

 

[swsmr]

you want to grow frags in your sump?? are you crazy, have you ever seen a sump and how dirty it looks after a few months,

 

[swsmr]

all the derbies from the tank will be collected in the sump,
if the sump is not kept in total darkness algae will grow like crazy all over all you equipment and pumps and the glass,
you will need to turn of the main pump every time you feed them or food will be swept away
the skimmer is too close to the return pump and all the tiny bubbles will be in the main tank,
the heaters is too close to the frag, water temp will be higher in the sump than the main tank.

 

[NYIntensity]

When filling, fill the DT up to but not over the overflows; fill the sump ALL THE WAY. Turn on your return pump. That should start the cycle of water moving out of the sump, filling the tank over the overflows, water will move through the drain into the sump, and bada-bing, your sump is now moving water, serving its purpose. The benefit is that if the power ever goes out (which it inevitably will at some point), the most water that will make its way back into your sump will be the original volume you filled in the sump...

 

[apex003]

<a href=showthread.php?s=&postid=11901822#post11901822 target=_blank>Originally posted</a> by swsmr
all the derbies from the tank will be collected in the sump,
if the sump is not kept in total darkness algae will grow like crazy all over all you equipment and pumps and the glass,
you will need to turn of the main pump every time you feed them or food will be swept away
the skimmer is too close to the return pump and all the tiny bubbles will be in the main tank,
the heaters is too close to the frag, water temp will be higher in the sump than the main tank.

It's meant to be a frag tank, so can't keep it in darkness. Will be using black acrylic for the dividers (pretreated with Krylon fusion) so the skimmer, bubbletower and return pump will have less light.

The baffles are meant to keep the bubbles down that you're talking about, and I've heard that you can dial the RS80 in so that it doesn't make a lot of bubbles.

I don't think your point about the heater is correct. With 600gph pumping through there, your not going to have a heat differential. Certainly locally right next the the heater, but I don't think in the sump as a whole.



Any other sump building gurus with some feedback? Should I be worried about the loud "waterfall" from bubbletower or skimmer overflow? I tried to minimize the fall to about 2" max, which should keep it pretty quiet, no?