Check my math please!

jgvergo · Sep 12, 2015

I am starting my first reek tank build. The tank is 24 x 48 x 17. It will be located 104 inches above the sump. I will be installing a bean animal overflow system and I will be using 1 inch, schedule 40 PVC, which has an inner diameter of 1.029".

I am figuring out how much volume I will need to leave in my sump to handle the drain down when the power is turned off.

I calculate the volume of 1 pipe to be 104 * pi * (1.029/2)^2 = 86.48 cubic inches = 0.375 gallons
I assume two of the pipes are always full and in a worst case situation, 3 are full, which means 1.1 gallons could be in the pipes.

I intend to install siphon breaks so 1/2 inch of water will siphon off.

0.5 * 24 * 48 = 576 cubic inches = 2.49 gallons

Total drain down of pipes and water from tank =2.49 +1.1 = 3.59 gallons

I think I will double that number and leave 7 gallons of space in my sump.

Make sense? Am I missing anything?

Thanks in advance!!!
John

saltyphish · Sep 14, 2015

Bump!

jgvergo · Sep 14, 2015

saltyphish said:
Bump!

Do you mean I should increase it from 7 gallons?

TheEngineer · Sep 14, 2015

Your math looks fine to me. I would leave more space than that though. Are you trying to maximize your water volume?

melypr1985 · Sep 14, 2015

jgvergo said:
Do you mean I should increase it from 7 gallons?

He was simply bringing your question back to the top of the list to help get you some answers. Sorry though, I can't comment on the math as I can't follow much of it. It is a great idea to leave extra room in your sump for the emergency water drainage though.

redfishbluefish · Sep 14, 2015

I did the exact same thing when I planned my sump because I wanted to maximize the volume in my sump. The very first thing other reefers say when they see my sump is, "Doesn't it overflow when you turn off your pumps?"

By the way, your math looks just fine. However, here are things I left out with my calculations that ended up not being a problem because I also added extra volume to my calculations. I didn't include any of the things in my sump that could add volume.

As an example, I have seven inch diameter socks, where the top lip is 3-4 inches above the water level of the sump. When it clogs and overflows, and I turn off the pumps, that volume above the water level is added to the sump:

I also did not include the volume in the skimmer, which would be difficult to calculate, but I think is minor. And I eventually added a biopellet reactor that sits above the water level and is full of water....and that volume wasn't included.

My original calculations were to fill the return section just to the level of the baffles. However, with the added volumes mentioned, it is 1/4 to 1/2 inch above the baffles.

So by you doubling your calculated volume, you should be just fine.

jgvergo · Sep 14, 2015

melypr1985 said:
He was simply bringing your question back to the top of the list to help get you some answers. Sorry though, I can't comment on the math as I can't follow much of it. It is a great idea to leave extra room in your sump for the emergency water drainage though.

Ah, I am now a little of a newbie. Thanks for the explanation

jgvergo · Sep 14, 2015

redfishbluefish said:
I did the exact same thing when I planned my sump because I wanted to maximize the volume in my sump. The very first thing other reefers say when they see my sump is, "Doesn't it overflow when you turn off your pumps?"

By the way, your math looks just fine. However, here are things I left out with my calculations that ended up not being a problem because I also added extra volume to my calculations. I didn't include any of the things in my sump that could add volume.

As an example, I have seven inch diameter socks, where the top lip is 3-4 inches above the water level of the sump. When it clogs and overflows, and I turn off the pumps, that volume above the water level is added to the sump:

I also did not include the volume in the skimmer, which would be difficult to calculate, but I think is minor. And I eventually added a biopellet reactor that sits above the water level and is full of water....and that volume wasn't included.

My original calculations were to fill the return section just to the level of the baffles. However, with the added volumes mentioned, it is 1/4 to 1/2 inch above the baffles.

So by you doubling your calculated volume, you should be just fine.

jgvergo · Sep 14, 2015

Thanks RedFishBlueFish! I am also trying to maximize the volume of the filter and the entire system on the assumption that more is better. I have another question for you. I can see that you hard plumbed the overflow into the filter sock. Do you have any difficulty removing the filter socks to clean them? Does the overflow line sit below the surface of the water?

tigerdragon · Sep 14, 2015

What size sump are you going to be using i would go with a 40b for a sump should give you plenty of room and then some

redfishbluefish · Sep 14, 2015

jgvergo said:
Thanks RedFishBlueFish! I am also trying to maximize the volume of the filter and the entire system on the assumption that more is better. I have another question for you. I can see that you hard plumbed the overflow into the filter sock. Do you have any difficulty removing the filter socks to clean them? Does the overflow line sit below the surface of the water?

Everything is glued up except the connection just above the 45 degree elbow....that's just friction fit.

I'm also not sure what you are asking about my overflow. I have a 1500 gph Glass-Holes overflow with saw-teeth. The water level drops about a 1/2 inch in the DT when the pumps are turned off.....all going down the overflow to the sump until the water level in the DT is at the bottom of the saw-teeth.

jgvergo · Sep 15, 2015

That's what I needed to know RFBF. Re: my overflow question, I used the wrong term. I meant: "does the end of the hard plumb PVC from the overflow sit below the water line in the sump?"