Adequate Sump Size for 90 Gallon

[Thalasstronaut]

Hello all,

Looking for some practical experience here. I have a 90 gallon drilled tank, on a home built stand.

My plan was to have a 40b as a sump underneath, but after dry fitting everything, I realize I have to put my sump on a platform on the bottom of the stand (I can’t rest it on the floor, the frame of the sump is too tight together to “sink” the sump.) Additionally, the interior pieces of the frame make it so there isn’t a true rectangle underneath, so I would have to scoot the sump over a bit towards the middle. All this is to say that I have a relatively tight fit above and to the side of my sump. I don’t currently have a protein skimmer or ATO, but I wanted to be open to possibly adding them as needed. And the 40 would make both things difficult to fit in.

My question is, will a 20 gallon sump be adequate for this size display tank, plus a display refugium? I could “sink” a 20, and would have room to spare on the sides. I would just have really a heater, some LR, and a return pump. Would possibly add a skimmer at some point. As far as I’m thinking, I just need my sump to be able to handle the run off from the display and the fuge when power cuts out, yes? Aside from the lower overall system volume of water (which I could conceivably compensate for with a larger fuge) is there any reason not to go smaller and more accessible? The alternative is rebuilding the stand and I already did that once soI am trying to save myself a headache.

 

[TX_REEF]

you can use a 20 long, but be super cautious that the 20 can handle the full water volume that would drain from the display in the case that your return pumps fails or the power goes out. If it can't, your floors are getting wrecked.

Maybe check out a 29h or 30 long tank? that'll give you some more volume to work with

 

[Subsea]

Hello all,

Looking for some practical experience here. I have a 90 gallon drilled tank, on a home built stand.

My plan was to have a 40b as a sump underneath, but after dry fitting everything, I realize I have to put my sump on a platform on the bottom of the stand (I can’t rest it on the floor, the frame of the sump is too tight together to “sink” the sump.) Additionally, the interior pieces of the frame make it so there isn’t a true rectangle underneath, so I would have to scoot the sump over a bit towards the middle. All this is to say that I have a relatively tight fit above and to the side of my sump. I don’t currently have a protein skimmer or ATO, but I wanted to be open to possibly adding them as needed. And the 40 would make both things difficult to fit in.

My question is, will a 20 gallon sump be adequate for this size display tank, plus a display refugium? I could “sink” a 20, and would have room to spare on the sides. I would just have really a heater, some LR, and a return pump. Would possibly add a skimmer at some point. As far as I’m thinking, I just need my sump to be able to handle the run off from the display and the fuge when power cuts out, yes? Aside from the lower overall system volume of water (which I could conceivably compensate for with a larger fuge) is there any reason not to go smaller and more accessible? The alternative is rebuilding the stand and I already did that once soI am trying to save myself a headache.

Design your flow into display from sump pump with a vacuum break to limit volume that will drain into your 20G sump when power fails.

 

[Thalasstronaut]

you can use a 20 long, but be super cautious that the 20 can handle the full water volume that would drain from the display in the case that your return pumps fails or the power goes out. If it can't, your floors are getting wrecked.

Maybe check out a 29h or 30 long tank? that'll give you some more volume to work with

What’s the process for determining that? Like how do you know what the sump can handle? Do I just plug or cap the drain from the display and leave the sump empty, fill the display, and then drain it into the sump, basically seeing what would come out of the display and marking the level in the sump? Or is there an easier way?

 

[Thalasstronaut]

Design your overflow drain from display to sump with a vacuum break to limit volume that will drain into your 20G sump when power fails.

How does one do that? I already have the plumbing kit for the tank, is there an additional modification needed?

 

[Subsea]

How does one do that? I already have the plumbing kit for the tank, is there an additional modification needed?

I don’t know what is included in your kit. Are their directions?

 

[Subsea]

What’s the process for determining that? Like how do you know what the sump can handle? Do I just plug or cap the drain from the display and leave the sump empty, fill the display, and then drain it into the sump, basically seeing what would come out of the display and marking the level in the sump? Or is there an easier way?

While running your system, unplug the return pump and see how much water drains into sump. The initial run should be done with lowest level in your sump. The footprint of the 20G tank is about 1/2 of the 90G display. That means when 1” drains from display, the sump level will increase by 2”.

 

[TheFunnyFarm]

What’s the process for determining that? Like how do you know what the sump can handle? Do I just plug or cap the drain from the display and leave the sump empty, fill the display, and then drain it into the sump, basically seeing what would come out of the display and marking the level in the sump? Or is there an easier way?

Multiply length x width x depth of water above the point of siphon break (in inches) and divide by 231 to get the volume in gallons.

 

[TX_REEF]

What’s the process for determining that? Like how do you know what the sump can handle? Do I just plug or cap the drain from the display and leave the sump empty, fill the display, and then drain it into the sump, basically seeing what would come out of the display and marking the level in the sump? Or is there an easier way?

1. determine the sump water level. use volume calc to determine operating volume.
2. determine display operating and minimum (if power went out) water levels. Measure the height change and again use volume calculator.
3. if 1+2 is greater than 20 gallons (or your chosen sump volume), you're in trouble.

Aquarium Water Volume Calculator - Bulk Reef Supply

Bulk Reef Supply - Saltwater Aquarium Supplies for Reef Tanks

www.bulkreefsupply.com

 

[Thalasstronaut]

Just want to thank everyone for the input. While attempting to level my stand today I became less than confident in its integrity, so I think I will be just rebuilding it anyway and using my 40 as intended.

I suppose I’ll ask here if anyone knows of a way to build the standard rocket engineer stand so that I can sink the sump between the bottom of the frame? If I build it wider, then the display tank obviously wouldn’t be sitting on the rim on all 4 sides.