Do I need a valve on sump plumbing?????
 

Hey everyone,

I am just putting a sump in for my tank and I am wondering if I should be putting a valve in either the drain line or the return line?

Also I am wondering if a 1 inch drain line will be enough for my 50 gallon tank. I am planning on running around 700 gph.

Any advice will help!

I would recommend having valves on both. Ball valves on return lines and a gate valve on the drain. Controlling both helps for water changes and controlling water flow rates. I close my returns so the tank doesn't drain and I can keep the power heads on while I do water changes.

How is your tank plumbed?

Im not fully sure what type of system it is called. But I have elbows facing up that attach to the bulk head for the drain and the return. For the Drain it leads into a t joint with a cap on one side with a small hole to stop the gurgling and then drains down to the sump on the other side.

Thanks for the advice, I will put a valve on both the lines.

I think putting valves on overflow/drain lines is insane myself. The amount of water that would drain down any one that is properly designed should be miniscule, and obviously a sump should be able to handle it (in the case of a power-outage, etc...). I've seen people make the mistake of closing drain lines and having tanks overflow, or a partly-closed valve just allows opportunity for stuff to clog it. Risky IMO. The only exception is something like a herbie or beananimal overflow... but in those cases you have unobstructed back-up drains.

Just my 2 cents,

Cheers,

Chris

Okay, well thats a consideration. I can always add the valve later if I need to i guess.

A valve on the return line for sure but not the drain unless you have two drain pipes in a herbie configuration.

Your drain size is fine

with an external return pump handy a valve/union on both sides for servicing

drain
 

i would probably go with a bigger drain.i'm using a stockman with a 2" drain

I'm not sure how easy it would be to change out a 1" bulkhead to a 2" bulkhead, you would have to redrill the hole and even then there will not likely be enough clearance for a 2" bulkhead in the overflow box of a 50 gallon tank. a 1" drain will run up to 700 gph without an issue, and more than likely this is not the actual flow rate it will receive.

windcoast, what pump are you using or plan on using?

I have a gate on my drain, nothing on my emergency just it gets plugged. On the return I am running a check valve, which I reccomend. In 3 years I have not had anything overflow with this set up.

On my cube I had ball valves on the return and drain... no check valve. Now this set up I Had a spill once which fried a powerbar. everytime I did a water change I had to close the return line, there were a few times I almost forgot.

The flow though a gravity fed drainage line that discharges to atmospheric pressure can be roughly calculated using the continuity equation as it is a product of flow velocity and cross sectional area.

Q = A * V

Where Q is flow rate, A is cross sectional area of the pipe, and V is velocity.

The units work out this way:

M^3/sec = M^2 * M/Sec
OR
Ft^3/sec = Ft^2 * Ft/Sec

You can almost neglect head pressure as this will be offset by frictional losses in the pipe.

Remember you need to switch your time units from sec to minutes and convert to Gallons to get you gpm rate.

A good article for this can be found here:
http://www.agf.gov.bc.ca/resmgmt/pub...s/590304-5.pdf

Hope this helps.

so what's the velocity?

Well ideally you would measure this lol, but I dont see that being practical in this scenario. You could do this the way the pdf I posted goes about it, but this would be tough to find tables for as our elevation changes are small, or so I assume. Another way to do this would be to estimate the velocity based on gravitational acceleration:

9.81m/s^2
OR
32.2ft/s^2

Time how long it takes from the first overflow trickle till when its out of the piping. For example say it takes 2.5 sec to flow through, this would translate into a velocity of 24.5m/sec. This can give a ballpark figure. The more water volume on top of the intake though will create some head pressure, which then changes all of this. This assumes gravity fed drainage into atmospheric pressure.

Im sure if you google it someone has done the math!

Yeah I was attempting to point out that equation isn't useful here, it's only for sizing pipe when you have a desired flow rate and velocity or solving for a different variable with the other two known. The velocity will actually depend on a few things including pressure difference, density (which is variable as well due to an inconsistent mixture of air and water), major loses from pipe friction and minor loses from pipe fittings. While it's completely possible to calculate this all it would be a complete waste of time especially since RC has been nice enough to make a simple calculator that estimates the required pipe size based on flow rate.
http://reefcentral.com/index.php/dra...flow-size-calc

Well to state that the equation isn't useful here I believe is wrong. You are correct that it depends on a few things, such as air water mixtures, whether or not it is laminar/turbulent flow. You could easily solve for a Reynolds number and jump into a whole bunch of fluid mechanics equations. But the RC calculator would of course be the fastest and simplest way to go. Good find.

Nah it's pretty much useless, it depends on more than a "few" things.

Hah ok... well that was a good chat.

Im sure the RC calc has accounted for all these variables then.

Have a good one.

drain size from RC (gravity)

Beananimal's siphon calculator

I think 1" drain on a 50g is adequate. Have a valve on the discharge side of your pump and use it to tune your flow. If you are getting lots of bubbles from the discharge pipe into your tank close the valve until they stop, likewise if the return section of your sump keeps fluctuating, as it should remain at a constant level (with evaporation as the exception of coarse). It's that easy!

Hey! Im using a Hydor seltz pump (800 gph model). I calculated the loss in the gph from the head and it equals out to about 500 gph.

Thats pretty much impossible for me to do. I already have the largest bulkhead that I can get for the hole. And I can't drill it out anymore without affecting the structure of the tank.

I can maybe step up to a larger pipe ( 1 1/4" or 1 1/2"), but I don't know if it is a benifit considering the bulkhead restricts the flow.

I used the calculator that you showed, and it seemed to back up the size of the pipe and the flow rate. So So far it seems like a 1" pipe will work for me with a valve on the return.

You could also put a valve after the return pump to control flow rates if you don't want one on the drain.