Sump volume needed for pump shutdown

[Crooked Reef]

Trying to estimate how much water would be drained from a 150 gallon marine land tank when the pump shuts down. Does anyone have one that can either calculate the volume their sump fills when the pump is off? I'm upgrading from a 90 gallon to a 150 gallon and trying to see if I need a bigger sump or if I can use my current one. Thanks.

 

[mcgyvr]

Thats dependent on the size/length of your plumbing as well as the height/type of overflow box and how the elbows are....depth 9f return outlet. ....and a few other potential variables...

Its not hard to figure out by just examining your system first hand....

 

[MondoBongo]

Thats dependent on the size/length of your plumbing as well as the height/type of overflow box and how the elbows are....depth 9f return outlet. ....and a few other potential variables...

Its not hard to figure out by just examining your system first hand....

+1.

back flow from siphons and overflow configuration will govern this more than anything else.

i usually just trial and error it. start off low, and raise it till i find a good spot. if you start with your main return off, fill the sump to the desired level, then flip it back on, you should know the max level.

 

[Crooked Reef]

Yeah, my issue is that the sump is currently in the stand under a running 90 gallon. The only way to remove it due to the front brace on the stand is through the top of the stand. I can’t test it out so I was seeing if anyone had this particular tank to ballpark a gallon amount. I’ll probably just get a different sump.

 

[MondoBongo]

why can't you test it out, i'm confused?

all you need to do is turn off your return pump and allow the main pump to drain. with the return pump off, fill (or drain) the sump to the desired level. adjust your ATO, and then turn the return pump back on.

 

[allendehl]

You may be able to estimate the volume your sump can hold but I don't know how you would know how much of that will be contributed by the overflow discharge of the new tank.
If you are committed, you can set it up and run a test with tap water, slooowly, if you realize you need an upgrade all you lost is gallons of tap water, dump it, remove the empty tank and replace the sump.

 

[blowmecius]

If it is the 150 high (48"x24"), for every inch the tank drains,it will add about 5 gallons to the sump. Assuming you have a 30 gallon (36"x12") sump, which is about as big as you can get under a 90, every gallon you drain will raise the sump 1/2 inch.

If it is the 6 foot tank, every inch of tank water is about 5 1/2 gallons.

Either way, I think you need a bigger than 30 gallon sump, but you never said what size you have.

 

[MondoBongo]

If it is the 150 high (48"x24"), for every inch the tank drains,it will add about 5 gallons to the sump. Assuming you have a 30 gallon (36"x12") sump, which is about as big as you can get under a 90, every gallon you drain will raise the sump 1/2 inch.

If it is the 6 foot tank, every inch of tank water is about 5 1/2 gallons.

Either way, I think you need a bigger than 30 gallon sump, but you never said what size you have.

i have a 30 long under my 155. runs about half full normally, about an inch from the top with the pumps all off.

 

[blowmecius]

i have a 30 long under my 155. runs about half full normally, about an inch from the top with the pumps all off.

If it works for you good on ya. That's just too close for my comfort.

 

[Crooked Reef]

why can't you test it out, i'm confused?

all you need to do is turn off your return pump and allow the main pump to drain. with the return pump off, fill (or drain) the sump to the desired level. adjust your ATO, and then turn the return pump back on.

I can test it on the 90 no problem. The 90 has been running for a few years but I can't get it out of the 90 gallon's stand to run a fill test on the 150 that I am upgrading to.

 

[Crooked Reef]

If it is the 150 high (48"x24"), for every inch the tank drains,it will add about 5 gallons to the sump. Assuming you have a 30 gallon (36"x12") sump, which is about as big as you can get under a 90, every gallon you drain will raise the sump 1/2 inch.

If it is the 6 foot tank, every inch of tank water is about 5 1/2 gallons.

Either way, I think you need a bigger than 30 gallon sump, but you never said what size you have.

It is the 150 tall. Current sump is 30"x14"x16" or 29 gallons. Sump is custom designed by my lfs owner who has an acrylic manufacturer make them for him. I can give him any baffle set up and dimensions I want and he can have it made for me, but honestly for the cost I can order a trigger systems ruby 36" sump and actually save money. His standard 36" sump costs $389 but changing the configuration will add to the cost a bit. I am leaning towards the 36" trigger or a 40 gallon breeder build with baffles cut by a local glass shop.

 

[blowmecius]

With that sump, every inch you drain from the tank will add about 2.75 inches to the sump. If your water only drops an inch when you turn off the pumps you are fine with the existing one.

That said, you are setting up an awesome new system. If the coin isn't a problem get the 36"! Bigger is better, buy once cry once, all the cliches. The sump you have can always stay with the 90 which you know you will be setting up again.