Sump placement question

[JMaxwell]

I am considering moving my sump & equipment out from under my tank so that I can get more room to maneuver, a bigger sump, incorporate a refugium, and save some head loss.

Here is the thing. I would like to put my sump on a stand so that I don't have to bend over or crawl on the ground to service everything. For some reason, every sump that I see is on the ground, even if its in a separate room. Why?

It would seem to me that the sump could be any height that is below the minimum acceptable water level in the tank/overflow box. I have a tall, corner overflow with a drain in the bottom. The tank is tall at 40". The operating water level is around 72" high and the bottom of the tank is around 32". I'd like the top of the sump to be around 40". Is this a problem for any reason? I realize that my overflow box would operate with water in it, but is that bad?

Anyway, this is unconventional, so I thought I would pose the question.

Thanks in advance for any responses. I'd feel especially good if anyone had pictures of a setup like that.

[Scoobaman17]

I've seen them go from the bottom of the overflow straight at a 90 through the wall into a sump on the other side or across the wall to the other side of the room. Head pressure always wins just don't go up, that gets too complicated. I'm sure that the minimum level would be the bottom of the overflow which could be the same as where you want the water level to be in the sump. Just remember you'll need a bigger power head to reach from wherever it is you put the sump. Someday I plan on a room just for the tank which is in the wall. The sump will be on the side wall not directly under the tank.

[evoracer]

I run my sump on my 50G right behind the tank, on the same stand. So long as the water can drain into the sump it is no problem. Actually a benefit is virtually no head on the return pump.

[JMaxwell]

Thanks for the input. I am not experienced at setting up sumps, but my fluid mechanics classes of 20 years ago lead me to beleive that right next to the tank is actually best for saving on head pressure.

That said, I've had some more experinced people tell me it had to be below the bottom of the tank, but not a single one of those people could tell me why, or what the consequences would be.

I'll definitely save on head pressure. Of course, I'll be adding a few horizontal feet of pipe, but I'll also be losing 3-4 feet of vertical head.

Anyone else put a sump higher than ground level?

[Toddrtrex]

But, if you have the sump right next to the tank -- same level --, you will have issues.

You could use a pump to get the water either to the sump, or to the tank. But, you can't have two pumps pushing and pulling the water. The reason being is that you will never be able to get them matched perfectly -- even if you are using the same pumps. One end has to be gravity fed.

So, you can have the sump above the tank, that will work, they just can't be on the same level.

[evoracer]

They can be on the same level. The water drains from the top of the display tank, and as long as the sump is shorter than where the water drains from you won't have a problem. It is still a gravity feed. It doesn't have to go multiple feet down to be a gravity feed. My 50g is working proof.

[JMaxwell]

<a href=showthread.php?s=&postid=11947194#post11947194 target=_blank>Originally posted</a> by evoracer
They can be on the same level. The water drains from the top of the display tank, and as long as the sump is shorter than where the water drains from you won't have a problem. It is still a gravity feed. It doesn't have to go multiple feet down to be a gravity feed. My 50g is working proof.

I am with evoracer here. Even if the are the same level, every bit of water pumped from the sump to the tank will go over the overflow and back to the tank. Under normal operation, the waterline in the tank will be higher than in the sump. When the pump shuts off, they tank water line will go to the height of the overflow, the overflow box and the sump will go to equal heights. (If the sump is below the tank, the overflow box will completely empty. I would think another nice feature of this is that you don't need as much empty room in your sump to if the pump shuts off as your overflow box will stay full of water.

As for putting the sump above the tank, I don't think I would do that for a number of reasons. The system should be designed such that the sump water line is below that tank water line under normal operation. In any case, its certainly true that trying to pump water in both directions is an accident waiting to happen.

I am still looking for any contrary opinions on placing a sump off the floor.

[alve]

I can be wrong but let's say that the water level of your sump is 10 inches below the water level in the DT. The tank is drilled from the bottom so the water flowing through the overflow comes out underneath the tank and then travels up into the sump.
When power goes off (or you turn of the main pump) then the overflow pipes would be filled with water to 10 inches below the DT water level.
When you turn your pump back on, I wonder if the water will start flowing fast enough so it doesn't back up and overflows the DT?
It takes a lot more to push the water down the overflow and then back up to the sump then when it is just going down a completely empty overflow pipe.
I think if you have too much flow coming from your pump it will not start draining fast enough. Once it is going it could be fine but just the start could cause a problem? I could be wrong.
What do you guys think?

[Scoobaman17]

Check valve, But also if it's acrylic you could drill a new hole at any height on the back of the overflow, close off the old hole. Then you could even use the overflow box as a fuge. I've seen that many times. Even with durso standpipes. So you could have the hole lets say 2 inches down from the DT water level, 90 it to the sump. Rule of thumb it's best and easiest to have the sump water level below that of the DT. Avoid problems.

[JMaxwell]

<a href=showthread.php?s=&postid=11949066#post11949066 target=_blank>Originally posted</a> by alve
I can be wrong but let's say that the water level of your sump is 10 inches below the water level in the DT. The tank is drilled from the bottom so the water flowing through the overflow comes out underneath the tank and then travels up into the sump.
When power goes off (or you turn of the main pump) then the overflow pipes would be filled with water to 10 inches below the DT water level.
When you turn your pump back on, I wonder if the water will start flowing fast enough so it doesn't back up and overflows the DT?
It takes a lot more to push the water down the overflow and then back up to the sump then when it is just going down a completely empty overflow pipe.
I think if you have too much flow coming from your pump it will not start draining fast enough. Once it is going it could be fine but just the start could cause a problem? I could be wrong.
What do you guys think?

This is why I'd like to know if anyone has experience with this. What happens in a startup scenario like that before the drain line is full? I would think that as the pump starts driving water into the DT and over the overflow, the level of water in the drain pipe will rise at nearly the same rate on both sides. Since the outlet on the sump side is lower than the overflow weir, the water dumps into the sump.

I think its critial that the drain line does not go up from the bottom of the display and then back down into the sump as that might trap air in the line and cause the back up you are talking about. (I think most people envision the drain entering the sump from the top and pointing downward.) I was even thinking of running the drain line from the bottom of my tank to the bottom of a chamber in my sump like a big "U" so that there was never any air in it, unless I drained it on purpose. If I did that I think it would need the ability to drain as it would probably collect detrius over time. the benefit is that both sides fo the drain line would be submerged all the time, so it might be completely silent.

It worth noting that my tank is 40" tall and the top of it is about 72" high (bottom 32" high). I am thinking that the top of my sump would optimally be about 36"-42" high. As a result, the overflow would have to fill up 30"-36" of head pressure greater than the drain exit to cause a problem. I think you would have to be far more careful if you wanted to run a sump with a wter line just a few inches below the display water line. I am talking 2.5 to 3 feet difference from DT to sump.

As for drilling a higher drain line, good suggestion but it can't happen. My tank is built into the wall and the drain is in the back corner. I don't know why I would need a check valve, and I've heard that they are unreliable.

[BeanAnimal]

Guys, water seeks its own level.

You can have two tanks side-by-side connected by a pipe. Pumping water FROM one tank INTO the other will result in water flowing through the connecting pipe. Pretty simple.

As long as you size the drains properly, then you will not have a problem.

In this case I would take the overflow output and turn a 90 right into the side of the new sump. No need to come in from the bottom. Create an L instead of a U.

[JMaxwell]

Thanks.

[BeanAnimal]

Lets get into the details here..

What size return pump are you planning and what size is the overflow pipe? Is there more than 1 overflow pipe?

I see an eheim 1260 or 1262 in your future... quiet and reliable. With very little head you will get a fairly high turnover and do so very efficiently.

[JMaxwell]

I hadn't got to sizing the pump yet. I've only got a single 1.5" drain in a single overflow unfortunately, and I am stuck with that.

My overflow has about 15" linear inches of overflow with teeth. It also has a 1.5" diameter bulkhead drilled into it with a screen on the tank side and a 90 degree elbow inside the overflow box pointing up approximately at the height of the overflow teeth. So, while I've only got 15" inches of surface skimming overflow, I've got another 1.5" pipe worth draining into the overflow box. I'd guess that flows about all my 1.5" drain can handle. Any idea how much water can go though a fully submerged 1.5" drain line?

The drain will go through the wall to the outside and horizontally around 8 feet to the sump. I have a long narrow area to place the sump outside. I'll build a little shelter around it to keep the rain off. I may just use plastic sheeting on the sides to insulate in winter.

I figure that my new sump can stretch around 7' long, but should really only be about 16" wide. I'm thinking 24" total height of sump with operating levels in baffled areas at 21" height. I'll leave 3' linear feet of sump for the refugium. The other four feet can accomodate a skimmer, carbon, phosphate, heater, etc. and a couple of sets of baffles before the drain area. I thought that I would have the drain near the center, the skimmer and equipment area on the side closer to the tank and the refugium on the far end.

I'm thinking I'll put the calcium reactor, kalk stirrer, top off water, chiller and return pump under the sump.

The "L" idea to the sump won't work because the drain and return lines will have to be low to clear some obstacles along the way. The return pump on the ground will be a low point so its always full of water, but the drain line will go down from the tank and then go back up to the sump. This is why I suggested the "U" analogy going back through the bottom of the sump. I figure there won't ever be and air in the line that way.

I am thinking that the drain line would run under the length of the sump and rise in two places with tees. First, it would rise up under the section with the skimmers, etc. and then again into the refugium. (going to need valves and unions all over) The pipe would continue for a bit and end in a valve that empties to a drain. This way, I could shut off the pump, and dump enough water for a nice water change.

I haven't worked out all the fittings yet on the return, so I don't know the head pressure to expect. All I know is the vertical head should be between 2-3'

This tank has been in operation since 2005, but I did not design it originally. As a result, I am a first timer for this kind of design project. Any and all help is welcome.

Tonight, I delt with a different problem. It was over 80 degrees today here at the beach and was still over 75 in my house at 8pm. My #%#$^! pump to my chiller broke this weekend and my tank temp went to 87 in the sump and 90 in the tank when I got home. I guess this would have been a good time to have a fancy controller to shut off my lights automatically. That or a big sump outside.

Looks like the fish and corals will survive for now, but I worry about wiping out my bacteria population or something.

[BeanAnimal]

.43 PSI per foot of head. Note that the head is measured from the waterline in the sump to the waterline in the overflow box.

[JMaxwell]

Right. Vertical head from waterline in sump to water line in overflow box should be zero, so even better than I thought.

What does .43 PSI per foot of head mean?

[evoracer]

I guess I should clarify that my tank is drilled out the back, not the bottom.