tank drain

[mng777777]

You should aim for 10x-15x your tank volume through the sump each hour... 150 x 10 = 1500 GPH minimum and make sure that your overflow teeth, as well as your plumbing for your overflow, are deep enough to handle more than that so you don't end up with a flood.

 

[bwaller76]

see thats the problem...I find these overflow boxes that are rated for say 1800 gph but they just dont seem deep enough to me... like this one

Overflow box rated for 1800GPH - eBay (item 260537165732 end time Jan-18-10 12:00:30 PST)

 

[mng777777]

I just built mine, it's 30 x 3.75 x 6h I used .25" slots spaced at 5/8" across the front. I found a calculator that estimated it could handle 2000 gph.
Calculator 1
[URL="http://www.reefs.org/library/downloads/"]Calculator 2 Just Click The Link
[/URL]

 

[Rcpilot]

see thats the problem...I find these overflow boxes that are rated for say 1800 gph but they just dont seem deep enough to me... like this one

Overflow box rated for 1800GPH - eBay (item 260537165732 end time Jan-18-10 12:00:30 PST)

Thats HUGE!! I wouldn't doubt it will do 1800gph.

Now you just need to decide - you going to use 1 overflow or are you still planning to have dual overflows?

If you're going to use dual overflows that doesn't necessarily mean you need to drain the max out of each one. You could drain 1000gph out of each one with a 2" bulk head.

So let's say you want to push 2000GPH through the sump. You'll be draining around 1000gph out of each bulk head. Now you just need a pump that will do 2000gph with your head height. Let's assume your head is 5 feet.

A Little giant 5.5 would probably do the job.
A Gen-X PCX-150 would probably work.

Most 2" bulk heads will require a 70-75mm hole. Thats around 3" diameter for the hole. With the front flange it's going to be just a little under 4" diameter. That WILL fit inside the overflow box you linked too.

Hope this helps. If not let me know and I'll try it again. :compute:

 

[mng777777]

Just make sure that you account for failure so you don't end up with a flood. With the amount of flow you are talking about, if something backs up, you will drain your sump in a matter of minutes. Check out this thread for some ideas. Overflow

 

[bwaller76]

well, i know it is recommended that i have two overflows but sometimes I think I would like to have just one. I have researched the overflow thing and rc has given me the right plans to make sure to avoid the flood so im not as worried about that so much.

I thought I had everything down but then that little wtf bug starts showing up. I have that one pump that is rated at 1550 at full power which should do well in trying to drain what I figured.

The one thing that boggles my mind and sort of defies my mathematics is rc's indication that my tank would only drop like 1" - 2" when in operation. I guess it will just take some bashing for me to wrap my brain around it...and btw rc omfg those videos are the shiz! So it seems that I should get the overflow and the top of the box would be right at the brace? Or is there a different position? I saw yours rc and yours looked to be right at the top.

thanks for helping me

 

[Rcpilot]

It's glued up tight right under the inside lip. When my tank is running - the water level is right at the bottom of the outer plastic rim around the tank. About 1.5" below the very very top of the plastic rim.

The water level in the tank drops about 1.5 -- 2 inches down when the pump is shut off.

I'm uploading more video to photobucket. I'll post links here in a bit. I have about 10 vids of this if you want to see everything thats going on when the pump shuts off.

Some of these are older - I didn't have my in-sump skimmer at the time I made some of these videos. I DO have the in-sump skimmer now. So in a few videos you'll see the HOB fuge hanging on the side of the 20H refugium because i was initially using that as a skimmer.

 

[bwaller76]

ok so resurrecting this post to find out what size the overflow pipes should be. I have heard 1.5" and 1" would both work. I was going to use BeanAnimal's Bar and Grill - Silent and Fail-Safe Overflow System but i think i might just go with a standard two to three pipe drain system. How big should the drain pipes be? I have a pump that will do 1550 under ideal conditions. I have the 150 gallon and plan on about 1000 gph. Is there a calculator to find out how much water a 1" drainpipe vs a 1.5" drain pipe will evacuate? Any insights?

 

[mng777777]

Check here: PVC Flow I'd say that you'll be fine with 1" as long as you have a minimum of 2 drains. I used the BeanAnimal plumbing and only used 1" I have 1200gph through my return and I can dump a full 5g bucket into the tank without overflowing and it clears in about 10 sec. Hope that helps.

 

[bwaller76]

well i went out and bought 1.5 inch pvc piping for the setup. Upon looking at that chart it seems that perhaps 2100 gph is quite a bit for a 150 which would be 14 X water capacity every hour. Should I go and scale it back to 1"? Also with the ball valve couldnt you just close that a little bit to reduce the flow into the sump? It seems that one drain would do with an emergency overflow... Am I wrong?

 

[mng777777]

First NEVER use a ball valve to restrict flow on the overflow side. Debris/algae will get caught in it and cause a flood. It's only a matter of time. That said, you are fine to go ahead with the 1.5" since you have already purchased it. It is more than you need, but that won't hurt. The flow through the sump will be dictated entirely by the amount of water your return pump is moving, so even though your overflows can handle 2100gph, they will still only move 1500gph because that's all that your pump will actually be moving. I installed all 3 overfllows on mine because I've had enough floods in the past that it is worth it to me to have the extra security of having 2 fail safes. There is nothing forcing you to have 3, in fact with 1.5" pipe you could just do one, but if it ever gets plugged, you will regret not having the additional overflows.

 

[bwaller76]

well i did some thinking and I like the idea of two one inch drains and having the 1.5 being the emergency upturned drain as set up in beananimal's overflow system. The two 1" drains will give me backup in case of failure of one and the 1.5" very much large enough to pick up the slack in the event of a double plug. I ordered my top brace today too which will be here in 7-10 business days. Ill get started on that then drill the tank and get the plumbing done. now in the diagram for bean's overflow it shows ball valves should I not incorporate those...just seems like a shut off just in case of malfunction.

Also w00t my RO/DI is slated to be delivered tomorrow! I cant wait to get it setup...no more of this trying to condition my water for any of my tanks...plus my fry will like some new water!

SCHWING!

 

[mng777777]

I always use valves on everything just in case, but in reality you only need it on your main drain.