Krux, broomer diverting overflow=fuge + sump

[buddyboy]

Krux, or anyone familiar with the design in which he diverts the overflow coming from the main tank into the sump and refugium by using that Y connecter. I very interested in using this design and I was wondering if anyone has had any problems with it. I have a couple of questions and was hoping for any imput..
Let's say the overflow can handle 700 gph using a 1' clear tubing...
1) Do you then decrease water pressure in each by half , sending (350gph) to the sump as well as (350 to the refugium). I see that he uses a ball valve coming off the overflow to the fuge.
Which could regulate the flow into the fuge but is there any concern with back pressure on the overflow..I know gravity is creating the siphon or water flow.. If I understood it sounds as if he used a 1 1/2 ball valve, maybe that would mitigate any concern of an overflow.. Please give me any suggestions on how this could possibly go wrong, because I live on the 4th floor and a flood is not even a consideration. I will be using gravity to feed the sump, from the fuge by drilling a bulkhead and raising it a few inches above the sump... the return will consist of mag 9.5 pump connected to a similiar version of broomer5's spray bar.....
thanks,

 

[krux]

i use a 1" drain, which splits through a 1" Y, one leg of the y leading each to the refugium and to the sump. my overflow is rated at 650 gph, and the total flow to my tank via the return line is around 450 gph, so i have more than enough drain for pump.
on the side of the Y that leads to the fuge, i used a 1"-1 1/2" increaser, added in a 1 1/2 inch ball valve, and then used a 1 1/2" reducer to go back down so that the pvc i plumbed with would connect both to the reducer, and to my bulkhead on the refugium.
i do not have a ball valve on the side going to the sump, it is wide open.
as for back pressure, the setup is designed to utilize backpressure to control flow into the refugium. water is diverted at about 50/50 to each side initially, but by closing the ball valve on the refugium side, only a portion of the water passes through, forcing the rest to run into the sump. since the initial sump line is equivelant to that of the main drain line, it is able to handle 100% of the water, though it only receives about 75% of it.
the only issue that i have really had with my setup, is that since i use a stockman style overflow, some air goes down the line into the drain. bubbles do tend to build up in the line, i assume in the y, or at the base of the ball valve. this leads usually to occasional bubbles into the sump, the air taking the path of least resistance, rarely these bubbles hit the refugium, forced through the ball valve by the pressure of the water.
this however has never posed any sort of problem for me as far as backflow and overflow are concerned.
when making your purchases, be sure that your overflow has a significantly larger rating than your return pump (this is always wise not matter what type of plumbing you are doing) and if you are concerned being upstairs, i would suggest also putting a ball valve on your sump return line, especially if the ratings of the two are rather close.
when starting up your setup for the first time, start it with the ball valve half open coming from the return pump, and open up from there, making small increases in flow every 5 minutes or so to allow any air bubble acumulation to form.
as long as you do not plumb your system planning on your sump plumbing to handle 75% of the flow and your fuge to handle 25%, but instead plumb it so both can take the whole thing, you will guarantee yourself flood free performance.
good luck.
ps. on my next plumbing job i am going to do the whole thing in acrylic so i can watch where the bubbles form, as i think it would be interesting to watch. of course that is going to be a long way off, and i think you will most likely want to do your fuge before then, so waiting for my findings probably wouldnt be feasable.

 

[krux]

on a side note, after looking at steveweast's setup i will be stealing his drain engineering for my next setup. it consists of some simple plumbing which eliminates most of the air bubbles and splashing in his sump that come from the drain pipe, thus reducing the salt spray to almost nothing. here is a fast illustration if you want to try to work it in. the first down pipe carries watter, air bubbles move up and into the second down pipe, where they escape about an inch above the waterline, removing all potential for splashing while at the same time not adding any backpressure to the line.

 

[buddyboy]

Wow, Krux that had to be one of easiest, well said , understandable threads that I have read since visiting this board. I really appreciate your insight and willingness to give a amazing explanation to my question.. When you want an answer go straight to the horses mouth.. All I need now is to be able to find the y connector, been to already 2 home depots and know luck... but i'll find it..

 

[krux]

http://www.plumbingworld.com/pvc.html#wye
fifth item down, available in all normal sizes.

 

[pyro383]

One comment on the return pump being less than your overflow box max capacity. The return pump can be more gph than the overflow since you have a few calculations against you. If the overflow is rated at 600gph and goes straight down to your sump, that is 600gph. the return pump has head loss per foot, and bends ie 45 or 90 degree turns add to your head loss. Reefcentral has a head loss calculator for your use and is simple to use. I have a 700gph overflow box straight down to my sump but have a 1300gph return pump. After my 45's and 90's and squid, my head loss will be greater than my overflow. Also I have a ball valve on the return in case I need to throttle back a bit.

 

[krux]

yeah was talking discharge head pressure, not pump 0 head rating. good to point out though... sometimes people do not take their plumbing into account when choosing and buying pumps.