Can you critique my sump design please?

[scolley]

I'm starting my first reef tank, a mixed 29g. It's on a stand that had limited internal space, and that my wife loves - so a larger stand ain't happening. Due to aesthetic reasons, the decision has been made to go with a sump rather than the various HOB possibilities for a small tank. In trying to design as small sump design for a limited space, this is what I've come up with. I'll build it after I get feedback from you, to make my design is not somehow off base.

The first pic below shows the size of the stand interior, with the sump in it, with equipment in the sump and stand.

The next pic is just the sump, followed by some cut-a-way and side views for a bit more detail.











There are a few considerations in the design worth noting:

1) The return pump is external to reduce heat. Heat may be an issue in the room the tank is in.

2) The return pump is on a elbow - not ideal, but provides more space allowing the sump to be bigger. Any drag imposed is hopefully reduced by planning on a 1" bulkhead and elbow, vs. the 3/4" required by the pump.

3) The tuze 9002 nano skimmer is 13.3" high, and requires 3.5" clearance to remove the collection cup. With the 1/4" thickess of the bottom of the sump, it just barely exceeds the interior height of the stand. In the spot over the skimmer, I plan on raising that part of the cabinet interior by a few inches. Too hard to explain how, but it will work.

4) Due to the potential heat problem, I wanted an external protein skimmer, but everyone was small enough, and did not take too much additional overhead clearance for maintenance, appeared to be WAY too much skimmer for a 29 mixed tank.


I've never used a sump before, much less designed one. So I'm curious - do you think this will work? What have I done wrong?

Thanks in advance!

[brward5]

My only concerns would be that the sump doesn't look like it can come out of the stand after everything is set up. I know it seems like it wouldn't need to, but always design everything with disassembly and reassembly in mind. It is frequently advantageous to take everything apart (particularly for semi-annual vinegar baths). Overall, I like it. I think I would reduce the 10" you allocated for the return area. You won't need that much space. 4-6" after the bubble trap should be enough water volume to keep the pump happy.
Consider the height of the sump. Remember that when all the power is turned off, the sump needs to hold all the water that may drain in - some will be from the skimmer, some will be from the display. It looks like you're running water height will be 1.5 in from the top. You want that to be more like 8" from the top so you have plenty of available volume before it starts flooding. Also, in-sump skimmers cannot be fully submerged. There is an "ideal" water depth for the skimmer. Since you have a major height constraint, consider going with an MCE300 (Deltek) instead of the Tunze. That way your water level isn't as big a deal.
Be sure you include a union on the plumbing to the pump (after the ball valve) so you can remove the pump when you need to without a major hassle.
Depending on what kind of probes you plan to run, they don't always like to be right next to each other (ORP and pH come to mind). Build several probe holders around the sump so you can keep the probes away from each other.
Hope that helps.

[scolley]

Originally posted by brward5
My only concerns would be that the sump doesn't look like it can come out of the stand after everything is set up.

Actually it should come out of the stand quite easily. It's almost 5" less wide than the inside of the stand, and there is no brace in the way. Just open the doors and there is a nice big 26" gap to remove a 22" stand. Should work.

Originally posted by brward5
I think I would reduce the 10" you allocated for the return area. You won't need that much space. 4-6" after the bubble trap should be enough water volume to keep the pump happy.

Maybe I'm misunderstanding sumps. I deliberately made the return area as big as possible. Because that return area is my evaporation buffer. The drain and fuge areas will be at constant depths. But the return area can vary from 5.5" deep (or lower) to 10.5" deep, giving me a 2.6 gallon reserve at a minimum. So if I fill the sump up, I've got as many days as it takes 2.6 gallons to evaporate before I have to worry about water adding water. Am I missing something?

Originally posted by brward5
Consider the height of the sump. Remember that when all the power is turned off, the sump needs to hold all the water that may drain in - some will be from the skimmer, some will be from the display. It looks like you're running water height will be 1.5 in from the top. You want that to be more like 8" from the top so you have plenty of available volume before it starts flooding.

I thought I did consider that. Take a look at the calculations on the 1st page, toward the bottom. I calculate the backflow from the tank to be 1.3 gallons if the air-break holes in the returns are 1" from the top of the tank water. And due to the interior walls of the sump all being 1.5" from the top, the entire sump holds an additional 1.5" water. In this sump that totals 1.6 gallons. So with a 1.3g backflow, and 1.6g reserve volume, that gives me 0.3g slack, or room for error.

I thought I had this covered.

Originally posted by brward5 Also, in-sump skimmers cannot be fully submerged. There is an "ideal" water depth for the skimmer. Since you have a major height constraint, consider going with an MCE300 (Deltek) instead of the Tunze. That way your water level isn't as big a deal.

Looked at them - WAY too tall at 24" for the 17" stand interior. I could use one as a HOB, but as I stated earlier, I'm not going to hang anything on the tank. Or at least unless there is absolutely no choice.

Originally posted by brward5
Be sure you include a union on the plumbing to the pump (after the ball valve) so you can remove the pump when you need to without a major hassle.

Actually that was supposed to be a union. I guess I should have labeled it. It is the exact size of a union (I measured). The ball valve would go on top of the pump - not between the sump and the pump, based on the principal of keeping pump restrictions on the outflow side.

Originally posted by brward5
Depending on what kind of probes you plan to run, they don't always like to be right next to each other (ORP and pH come to mind). Build several probe holders around the sump so you can keep the probes away from each other.
Hope that helps.

You BET that helps! Thanks! I was not aware of that restriction. Wow! I guess I'll have to plan on a few more. Thanks!

Originally posted by brward5
Overall, I like it.

Thanks brward5! It's a 1st attempt, but I'm trying to learn as I go. And I did NOT know about that probe limitation. Thanks! And please let me know if I'm off base about using that return area as the "buffer" zone for evaporation and topping off with more water.

[scolley]

Originally posted by brward5
Be sure you include a union on the plumbing to the pump (after the ball valve) so you can remove the pump when you need to without a major hassle.

I realize now you were thinking that knob on the drawing (attached to the pump) was a ball valve because I've got to have one to close off the water if I'm disconnecting the pump. Sorry about that! I was assuming that I'd put a ball valve actually inside the sump. A little unorthodox, but I figured it saved precious space outside the pump.

Originally posted by brward5
Also, in-sump skimmers cannot be fully submerged. There is an "ideal" water depth for the skimmer. Since you have a major height constraint, consider going with an MCE300 (Deltek) instead of the Tunze. That way your water level isn't as big a deal.

Good point. Thanks. But in fact the Tunze 9002 works best in 7.0 to 8.6 inches. I assumed I was going to have to raise it a few inches (3") so that it was at optimal operating level. And since the level in the drain portion should be constant, this should remain fixed. And the only time this should change is if the pump cut out, causing an additional 1+" of water in the sump. And when the pump's not running, I assume I don't need to worry about sub-optimal skimming.

[Scottn29]

looks nice

[scolley]

Thanks Scottn29!


I guess what I was hoping to find by posting here, is if the overall design is sound. Like:

Was it correct to maximize the size of the return section to allow for several days of evaporation?
Is a refugium that's 10% of the actual tank size ok?
Is a sump that ranges from 28-37% of tank volume big enough to matter (beyond getting equipment out of/off of the tank)?
Does it make sense to have drains into both the refugium and the drain section (assuming the most flow going into the drain section) and have both of them spill into the return section?
Is it indeed OK to have the spill teeth for water leaving the refugium, doing without any bubble trap for that water?


Thanks in advance!

[Aquarist007]

Originally posted by scolley
Thanks Scottn29!


I guess what I was hoping to find by posting here, is if the overall design is sound. Like:

Was it correct to maximize the size of the return section to allow for several days of evaporation?
Is a refugium that's 10% of the actual tank size ok?
Is a sump that ranges from 28-37% of tank volume big enough to matter (beyond getting equipment out of/off of the tank)?
Does it make sense to have drains into both the refugium and the drain section (assuming the most flow going into the drain section) and have both of them spill into the return section?
Is it indeed OK to have the spill teeth for water leaving the refugium, doing without any bubble trap for that water?


Thanks in advance!

its generally not a good idea to allow for 2 days evaporation---the water should be topped up daily if not twice a day. In your size of tank leaving it for two days can raise the salinity considerably.

the size of the return section should also be based on how many gph that pump is returing to the display tank--you don't want that section to pump dry.

IMO you don't need to worry about bubbles returning from the fuge area.
You do have the water skimmed before it enters the fuge and then returns to the tank---that is a good setup.

[Wheel of Time]

Hey Scolley! Good to see you are gettign down to brass tacks and gettign ready to finally get into saltwater after your incredible planted fresh water endeavors.

The sump design is well thought out. My question is with the refugium since it is on the small side -- what are you planning on using it for? I dont think you need drains in 2 sections of a sump for a 29g tank personally. The teeth arent necessary, but wont impede anything IMO, but you may want to consider changing to a spray bar with the flow going toward the overflow /bubletrap. It will either keep any chaeto you may grow rolling, and keep detrius /particulates suspended and flow out to the skimmer area instead of sinking to the bottom (will the fuge have sand, lr, or be barebottom?) The bubble trap -- I prefer having it start over then flow under -- but its a personal choice (very similiar to the logic of a dsb in a bucket to keep the matter moving through to the skimmer).

Im short on time for a better response, but will touch base again later. Good luck -- we can chat at the next meeting more in depth

-- Seth

[scolley]

Thanks Cap'n! I do appreciate the point on the evaporation. I guess I was looking at that as a sort of safty valve - not planning on skipping top off, just looking for "padding" if something went wrong. But I stand well warned. Thank you!

But the statement below just plain confused me.

Originally posted by capn_hylinur
the size of the return section should also be based on how many gph that pump is returing to the display tank--you don't want that section to pump dry.

Huh? I'm figuring that if the tank's overflow and return tubing is sized to support flow to the sump potentially faster (as measured by GPH) than the return pump can pump it up - then the limiting factor is the pump. If so (pump pumps at a lower GPH than the return returns), how could the pump possibly pump the return section dry?

I don't get it. The return section should always remain at a steady level except for the effects of evaporation. Or the addition of water.

Good thing they call this the "New to the Hobby" section.

[scolley]

Seth - you ninja posted on me! But thanks for the feedback! I will seriously consider spray bar. And two drains seemed to make it easier - with the fuge draining into the return section - to make sure that critters in the fuge didn't find their way into the drain section (and my skimmer!)

As for the over/under/over question, I've got no idea. I was just copying designs I saw on-line.

I'm not really "getting down to brass tacks." Wish I were... No, this is not my 180 that I'm converting. This is just a little 29g that I figure I'll learn on before I invest the real time/effort/money into converting my 180. If I screw up on the 29g the damage shouldn't be too tragic. I figure that I'll learn on the 29 - all the while planning out the 180. And when the 180 gets built out, the 29g instantly becomes my quarantine.

That said, that's why I want the fuge. I want to begin to get some experience observing (through pH logs) the effect a light on macroalgae at night will have on stabilizing pH while the tank lights are off. And I also want to begin to get my feet wet in growing some critters in the fuge to feed the critters in the display tank. But knowing I want those two things (macroalgae and critters), I still don't know enough to answer your question about sand. Still learnin' I'm afraid!

Anyway, thanks for the help and feedback. Will definitely see you at the next meeting!

[scolley]

Just as a follow-up, nearly a year later, I changed the specs of the sump.

1. I increased the size of the fuge to make it extend across the front.
2. I modified the bubble trap to be adjustable height. That way I can adjust the height of the water in the skimmer section, rather than moving the skimmer up and down. My stand has NO room for moving the skimmer up.
3. I had ordered a small piece of acrylic that - when inserted and siliconed in place - splits the fuge into two sections. The first section being a DSB, which then overflows into the fuge. Since it's removable, it's not shown in all of the plans below.

The sump was built by Gen Watanabe at KritterProducts. He did a great job, and did it for a very, very reasonable price.

There's the final plans (less that fuge dividing insert I mentioned above).














And here's a back view of the sump. You can just barely see the adjustable height bubble trap.



And here it is squeezed into my tiny stand. And on the left you can see where I inserted that piece of acrylic to split the front fuge into two sections, one being the smallest DSB I've ever seen. But it works!

[Ben_n_Em]

Pretty awesome sump design. Ran into a lot of similar space issues on my 36 bow system. Also chose the tunze 9002 but a year later I'm fighting a pretty tough battle with green hair algae. I'm currently working to redo the sump to squeeze in a more beastly skimmer. Hope my end design comes out as clean looking as yours.

[scolley]

Thank you Ben_n_Em!

After 18+ moths of use, I can say I'm pretty happy with the design. I'm planning to use pretty much the same design - but scaled up - when I move to my 180. But there are some things I can say I'd change:

1. I'd omit the tubing/probe holders. I've found they can get in the way, and aren't always where you need them. I think it's better just to buy commercial holders and mount them as needed.
2. For my setup, the teeth between the refugium and the return sections need to be lower. My overall water level was just a shade too high with the return off. So I had to punch some holes just under the teeth with a drill to set the refugium water level about 1" lower.

And one thing that has been a minor issue is visibility to the back sections. Granted, I was trying to cram as much as possible into a tiny space, with little overhead clearance. And I can't stick my head in the stand and look into the sump, and what's in the back sections can only be fully observed by feel.

The design of a front and back halves set of sump sections eliminated clear view of the back sections, IF you can't fit your head in the stand to look down.

So, it's not proven to be PERFECT. But it's good enough I'll be using that design again for my 180g.

Thanks for the feed back.

PS - I realized that there is a difference between the final design, and the original posted at the top of the thread. I did not mount the return externally. It reduced the size of the stand too much. Plus, using an Eheim - as I am - does not reduce any heat by going external. So I just sized the sump to include an internal pump. When I scale this up for my 180, I intend to return to the externally mounted return design.

[Angel*Fish]

I saw you put a Quiet One in your diagram...On a side note, I had a Quiet One 4000 return pump and I'll never get another. It was not reliable about starting back up after a water change. And I sure didn't want to turn it off for feeding because it could be a pain to nudge it into restarting. After researching it, I found I wasn't the only one with this problem.

Mine was bought in 2005 and used for about 3 years. Maybe they are made better now? I don't know, but I'll go with a different brand after that experience.

[scolley]

Originally Posted by Angel*Fish

I saw you put a Quiet One in your diagram...On a side note, I had a Quiet One 4000 return pump and I'll never get another.

Wow! Good catch!

No... I didn't use a Quiet One, but an Eheim 1250. It's been outstanding in EVERY way. But I do need more flow through the sump, so I'm upgrading to an 1260. Will be a tight squeeze, but it should fit.

I've got NO experience with Quiet One's, except for reading lots on negative comments like yours. I've got lots of hours logged with various sized Eheim Universal pumps, and cannot say enough good things about them. The ONLY caution I would give anyone is to say DO NOT believe it when you are told they can be run externally (not submerged). Under enough head pressure their seals can break and the results can be ugly. And wet. So just just them submerged in the sump and they are sweethearts.

[Angel*Fish]

Good to hear The only negative comments I've heard about Eheims is wishing they were cheaper. My quiet one was external -ugh- I'll never do external again either. Thanks for the info, I'd have expected the Eheim to be ok.