Overflow box and sump questions

[KRod]

I'm going to be installing a sump on my 150 gallon tank and have a few questions.

For my sump, I'm trying to mimic this setup, as its pretty simple and allows for a nice fuge.
http://www.melevsreef.com/install_sump.html

First, I need to know the best size overflow for this tank.

http://www.drsfostersmith.com/product/prod_display.cfm?pcatid=18358
I'm thinking the 900 gph here?

So what size sump would accomodate this nicely? I'd like the sump to fit nicely under the tank...I was thinking a 40 gallon or so? How does this sound? I don't want it to take up the whole 6 feet of length under the tank...maybe 4 feet of it or so. Would I have problems with water overflowing if there was a power outage or if my pump failed?

That just leaves the return pump. I don't want anything too expensive, just a decent submersible return pump. What GPH rating would be best? I know it would be hard to say exactly, but any idea of a range I should be shooting for that would work nicely? Should it match the gph going into the sump?

Thanks in advance. I know I have a lot of questions, but I'm not too keen on plumbing and sumps and things like that.

 

[stingythingy45]

That overflow would work fine.
I had a PF-800 and it worked very well.

You have to leave a little room in the sump so that the water in the return line can drain back to the sump if there's a power outage.You also have to make sure a siphon doesn't occur or this will drain your tank to wherever the return line sits under the water line.

As far as the pump.I noticed in Mels build that he used a Mag pump.
You basically have to pick a size that will overcome the head pressure and still give you at least 10X turnover.Some of the other Reefer's here will have more experience than I do at this.I have a basement sump set up so it's different then just pushing 4 ft. or so.

 

[KRod]

Hm. Okay. I was hoping to order everything today (including some new lights...score! )...I'm just not sure what pump to get.
How do I prevent a siphon in the case of a power outage?

 

[MikeG]

For the return pump, I usually don't run anymore that what my skimmer pump does. If I have a skimmer that processes 500gph then I would use a return pump that put out about 500gph taking into accout head loss and plumbing loss. Any more flow through the sump and I think you are just circulating water. If that is the case there are muck more effecient wayt to do it such as powerheads in the tank or a closed loop. This way you are not struggling against head pressure.

 

[KRod]

I'm not sure I understand....If the overflow is putting more water into the sump than the pump is pushing back into the tank, isn't my sump just going to overflow?

 

[stingythingy45]

I'm not sure I understand....If the overflow is putting more water into the sump than the pump is pushing back into the tank, isn't my sump just going to overflow?

The overflow will only return the water that is pumped into it from the sump.
Think of it like having a hole in the side of your tank at a certain hieght above the waterline.As the pump in your sump adds water to the display by pumping water up through the return line the water level will rise.
When that water level reaches the hole it's going to flow out.Hopefully there's a hose leading back to the sump.
The Eshopps siphon overflow will work the same.It will only return water to the sump after a certain level is reached in the display.Enough to cause the water to return to the sump thus completing the loop.

 

[JohnK]

Yea, if you run 10X turnover through the sump your likely to have a constant battle with micro bubbles on your hands. Also, the faster the water is being pumped through the overflow, the more volume you'll need in the sump in case of a power outage so it doesn't overflow.

A very popular and efficient approach is to run less volume through the sump, and then have closed loop(s) in the display, and or power heads to keep the water movement up.

It is possible to run 10x or more through the sump, but it can cause a lot of headaches. I do it, but I'm also running a sump that's 18" wide which helps with the micro bubbles.

As far as pumps, just about any submersible will be less reliable than a quality external. Some people love those mag drives, but personally I only use them for paper weights and door stops. (they have a funny habbit of not restarting after the power goes off, usually when your not home).

As far as sizing, the overflow box needs to be able to handle more than the pump can pump. For example, if the overflow is rated for 800GPH you probably want a pump that will be pusing around 600 GPH after head loss. Pump water up, gravity brings it down at the exact same rate. If that rate exceeds what can go through the overflow, it will find another way (flood).

 

[stingythingy45]

Yeah,like John said.
You really don't need to move water through you sump at that high of a turnover.I'm probably only pushing aprox. 600-700 gph through mine and that's split with a refugium and a reverse durso with carbon/filter sock.
Here's a nice graphic showing how a overflow and sump work from Mel's site.

http://melevsreef.com/allmysumps.html

 

[Kev_DX]

I'm not sure I understand....If the overflow is putting more water into the sump than the pump is pushing back into the tank, isn't my sump just going to overflow?

If your overflow is faster than your return pump, your tank will only drain to the bottom of the teeth of the overflow. You won't be using your overflow to it's full capcity, but that's fine. Make sure you have enough room in your sump for the water to drain. The best way to test is to turn off the power. The water will drain into the sump until it is below the teeth of the overflow. Just make sure your return pump isn't faster than the overflow box, otherwise you might overflow your tank.

When the power does go off the water that is in your return pipe will reverse direction and flow back through your pump and into your sump. It will do this until air gets into the return pipe. If the output of your return pipe is near the surface of your tank, water will drain until air is sucked into the output.

If the output of your return is deeper in your tank, you'll need a siphon-break hole. To prevent your sump from overflowing, drill a hole in the part of of your return pipe that is in your tank, just below the water line. When the power goes off, water will drain to the sump until the hole is exposed to air. The air will then break the siphon and stop the water from flowing into the sump. I have two holes in mine, just incase one is blocked by a snail or something else. One hole is about 1/2 in below the water line. The other is 1 1/2 inches below.

I have a 125 gal tank. I have an overflow rated for 1500 GPH and a mag 12 return pump. My flow is too much, as it is loud when it splashes in to my sump. I'll be working on quieting it down.

Hope this helps.

 

[KRod]

Okay, well I think I'm going to go with the 900 GPH Eshopps overflow. So what GPH do you think will be ideal? Somewhere around 650-700? I used to have a table that told me this, but how do I calculate head loss? Unless its given somewhere in the specs of the pump.

I know a good external pump would be ideal, but I don't really have over $100to spend on a return pump. I'm also looking for something nice and quiet as all of this is going under the tank.

 

[stingythingy45]

Here's one for you.

http://reefcentral.com/calc/hlc2.php

 

[KRod]

Thanks.

So how about a Magdrive 7? How well would that work with my tank? Is that not enough flow after head loss?

 

[jbishop]

Thanks.

So how about a Magdrive 7? How well would that work with my tank? Is that not enough flow after head loss?

I heard the mag drives are power hogs. just my .02

 

[stingythingy45]

Some like these Ehiem hobby pumps.

http://www.marinedepot.com/ps_ViewItem~idProduct~EH1262~tab~1.html

But really I'm just going by what I've read and not real life experience with them.I'm sure that somebody will post here that has some experience with both Mag and Ehiem.One thing to consider,you're going to want something that's quiet as it will be under your display.It's no fun trying to mellow out and enjoy your tank with an outboard motor running underneath it.

 

[alpha0r]

I'm going to be installing a sump on my 150 gallon tank and have a few questions.

For my sump, I'm trying to mimic this setup, as its pretty simple and allows for a nice fuge.
http://www.melevsreef.com/install_sump.html

I like this sump. The only possible problem I see is no bubble trap between the fuge and return section. I have the same setup in my sump and it does cause bubbles to enter the main display.

First, I need to know the best size overflow for this tank.

http://www.drsfostersmith.com/product/prod_display.cfm?pcatid=18358
I'm thinking the 900 gph here?

The bigger the better IMO. You want to draw the thinest possible layer of water from the tank. Proteins collect on the surface so drawing in a super thin layer of water gets the most proteins into the sump so they can be skimmed out.

I would highly recommend that you have the tank drilled and not use an overflow box. Overflow boxes will lose siphon and flood your house. It's not a mater of if but when.

I really like this design.
http://www.beananimal.com/projects/silent-and-fail-safe-aquarium-overflow-system.aspx

So what size sump would accomodate this nicely? I'd like the sump to fit nicely under the tank...I was thinking a 40 gallon or so? How does this sound? I don't want it to take up the whole 6 feet of length under the tank...maybe 4 feet of it or so. Would I have problems with water overflowing if there was a power outage or if my pump failed?

Bigger is better in every way. I would go with a 75 gallon. Consider that the fuge volume should be at least 20% of the display volume. So in your case your looking at a 30gallon fuge.

That just leaves the return pump. I don't want anything too expensive, just a decent submersible return pump. What GPH rating would be best? I know it would be hard to say exactly, but any idea of a range I should be shooting for that would work nicely? Should it match the gph going into the sump?

If you go with the sump design you listed in the link you need to consider total return flow in two parts because the skimmer and fuge are fed separately. 1) The skimmer section should have 3-5x total system volume per hour. So 150+75=225 225x4=900 2) The fuge flow rate depends on what your main purpose is for having it. If you want to maximize macroalgae production you should use higher flow than if you want to target zooplankton production. Here you target the flow rate based on the fuge volume not total system volume. So lets say you decide you want to grow cheeto and keep it tumbling. You would probably need something in the 20x range. So 30gx20ph=600gph.

So in this setup you would want a pump that returns 1500gph after accounting for head presure (900gph for the skimmer section and 600gph for the fuge). You can use this calculation to figure out the actual return rate.
http://reefcentral.com/calc/hlc2.php

I would look into a reeflo pump and skip the Mag drive. I have a Mag 7 and it is very reliable but runs extremely hot IMO.

I agree with others that you should use a closed loop, tunze, or ecotech pump for the main circulation in your tank.

Thanks in advance. I know I have a lot of questions, but I'm not too keen on plumbing and sumps and things like that.

No problem. Hope this helps.

 

[JohnK]

Okay, well I think I'm going to go with the 900 GPH Eshopps overflow. So what GPH do you think will be ideal? Somewhere around 650-700? I used to have a table that told me this, but how do I calculate head loss? Unless its given somewhere in the specs of the pump.

I know a good external pump would be ideal, but I don't really have over $100to spend on a return pump. I'm also looking for something nice and quiet as all of this is going under the tank.

There are two major things to consider when planning this flow rate;
-Will there be supplemental circulation (closed loop, powerheads) in the display or not?
-The total circulation your shooting for will be determined mostly by what you want to keep. If this is to be a dedicated SPS tank then you will want FAR more flow than if it were a softie or other less demanding coral dominated tank.


FWIW / IMO ehiem pumps are in a whole different category from mag drive pumps. Ehiems are virtually silent and as near bulletproof as you can get in a submersible. Mag pumps use a lot of electricity, are often more noisy, and are reliable for maybe a year IME, then they tend to be very unreliable.

 

[alpha0r]

Jimmy is completely right here. A soft coral tank you would be shooting for around 10x display volume turn over per hour ~1500gph. A SPS dominated tank you should go for 30-40x per hour 4500-6000gph. At 1500gph though a 75g you are really pushing the limits. Any more would probably give you microbubble problems. You could probably fit a 125 under your 150 to slow things down a bit.

 

[stingythingy45]

alphaor,

Are you sure about these numbers?

"So lets say you decide you want to grow cheeto and keep it tumbling. You would probably need something in the 20x range. So 30gx20ph=600gph."

Everything I have read is 10X the volume of the refugium for chaeto.
So for a 30 gallon that would be 300 gph.I have a 10 gallon and run that at 120 gph.I just has to remove half of my chaeto as the seams were ready to burst.JMO...but I think that it's kind of a waste to send water through a fug with chaeto if the macroalgae isn't going to have time to use the nutrients from the water.
Also,FWIW I don't think that a return pump and fug should be used for tank flow.As a matter of fact I wouldn't even count that as tank flow.I would use PHs and or a closed loop system for that.

 

[JohnK]

Cheato does thrive in high flow, but IME it's also quite adaptive.

I think part of the notion that Cheato needs very high flow comes from A.Calfo's talks and or writings. He talks about the ideal being to have a ball of cheato being tossed around like a tumble weed. Nothing wrong with that approach, but cheato can grow well in slower flow.

Personally my ref is a 20L and it probably gets 5-10X turnover at best. I have to pull out about a basketball sized pile of cheato every month or two. Maybe not ideal, but it works.

 

[stingythingy45]

Cheato does thrive in high flow, but IME it's also quite adaptive.

I think part of the notion that Cheato needs very high flow comes from A.Calfo's talks and or writings. He talks about the ideal being to have a ball of cheato being tossed around like a tumble weed. Nothing wrong with that approach, but cheato can grow well in slower flow.

Personally my ref is a 20L and it probably gets 5-10X turnover at best. I have to pull out about a basketball sized pile of cheato every month or two. Maybe not ideal, but it works.

That's interesting about Calfo's take on refugium flow,John.
That's why I asked because I was curious.Obviously there's two schools of thought about this.

I hope to move into a 20L eventually,but that's my cycled QT right now.

I do the same as you.Every once in a while I'll reach in there and physically roll the chaeto ball so the bottom will get light as well.

Scuba kid,sorry didn't mean to steel the thread.