2" overflows & returns questions

[txfatcat]

Was thinking of drilling one of my tanks. I need to know many gallons per hour a 2" pipe will flow for an overflow down into a wetdry. I know 1" will flow 600gph so will 2" drain 1200 gph ?



Also what is the maximum a 1" return will flow? Need to know if it will do 1200gph.  

any help would be great.

[CichlidFan]

Re: 2" overflows & returns questions

sounds logical but I would do some research on the net to make sure....it maybe like 1400 GPH, seems I've read that before?

CF

[Delock]

Re: 2" overflows & returns questions

You will need a wet dry and pump to handle the extra flow of a 2 inch drain.

[CichlidFan]

Re: 2" overflows & returns questions

True ...maybe a couple mags 12's might do...??  

CF

[h0nkzz]

Re: 2" overflows & returns questions

I know 1" will flow 600gph so will 2" drain 1200 gph ?

mathematicall this cant be true. 2 x 1" will give you 1200gph.
2" drain should give you about 2400 gph

not sure. but thats what I was thinking

[Delock]

Re: 2" overflows & returns questions

Like Honkzz stated.. 2' drain would give 2400.


But in order to reach that  number you will need to run 2 inch to the wet dry and out to a pump with a two inch in/out back to a 2 inch return.

When you look at the reductions you will have to do from the overflow to the wet dry. your flow number will go down.

[eklikewhoa]

Re: 2" overflows & returns questions

Plus the sump has to be big enough to handle the amount of water filled that fast.

[Zulaab]

Re: 2" overflows & returns questions

how about using a flow rate calculator

http://www.1728.com/flowrate.htm

IF (BIG IF) .75" = 600 then 1" = 1000 gph, then 2" = 4100 gph.
This is using a rate of 7ft / second travel (about a 1/4 of gravity) -- this all depends on what kind of head you are looking at.

Now understand we are calculating the return rate because the down flow will always keep up with the return rate UNLESS there are any areas that are limiting the return rate. (external overflow box are limited by the U tubes.)  Where as there is usually no limiters on the downtube in a "Reef Ready" tank

[txfatcat]

Re: 2" overflows & returns questions

Ok let me explain what I have and what I am trying to do.


I currently have 2-mag 12's running with an external overflow box. The overflow box has 4-U tubes and 1 1/2" down lines to the wet dry.   My return back into the tank is a 1" and a 3/4"
It all works great but I have to watch the wetdry because if the filters are dirty then it cant handle the flow of the 2 mag 12's


I am wanting to drill my 265 gallon and I have a drill bit for a 2" bulk head and 1" bulk head.    I am going to drill 2 1" holes in the center section of the tank for a closed loop (eheim 2260 & uv filter)
The on one end only I am going to section off 4" of the tank for the overflow and drill 2-2" drains and maybe a 1" return for a single mag12 or mag18.

when I drill. I want to do it one time and be done.  Will or should I need to drill the 2-2" drains or can I do one 2" drain. Please keep in mind that i want to make sure this tank can be used as a reef tank or marine tank if the next owner wants or desires. I know the turn-over rates are a little higher for that.

I am trying to get rid of the stupid overflow box and clean up the exterior plumbing so there is none.

Zulab

you are correct in that I could have a 12" drain and will only drain as fast as its being refilled like if i ran a mag3.  just want to make sure that 2-2" is not to little or too much.  2" is a big hole to drill for nothing.

[Zulaab]

Re: 2" overflows & returns questions

Chris,

From EVERYTHING I have seen in the past and knowledge of overflows etc..  U tube overflows are notorious "low" flow where as a drilled pipe will increase your flow by a ton.  What is the length of tube from the Mag-12 to the surface of the water.   This will give you the head height you are running at right now.   I expect you are running about 7ft of head, slack in the line etc.. giving you about 2x 850gph rate..  This is higher than 1x Mag 24.  
Since your choke point right now is your 4 U tubes I would say a single 1 1/2" down pipe mimicking your current hose setup, dual 1" returns I am thinking continuing to use your double Mag 12's would actually be your best solution.

Look at Mag pumps water flow

[txfatcat]

Re: 2" overflows & returns questions

my overflow has 2x 1 1/2"  downs with 4 u-tubes.  I have 2" bit and bulkheads. So your saying that I would be able to get away with one 2" down/drain and then 2-1" returns.  That is easy and would make things alot simpler.  Like you said, I am trying to get rid or away from the stupid U tubes.





Thanks for all the input and advise here. I just dont want to over do it or goto any extra trouble if not needed.  Just ahve to be sure that I am headed in the right direction.

Thanks

[txfatcat]

Re: 2" overflows & returns questions***Updated***

Ok   here we go. Went to reef central and they have a great tool that calculates overflow drain size.  Here is what I came up with.

I drilled two 1" closed loop for an ehiem 2260 or other setup/filtration.  Then drilled two 1" drains. I figured this was plenty because my big custom overflow box had two 1.5" drains and it flows stupid volumes and is still limited because it uses U-tubes.  I also drilled a 1" return so this will give me plenty of return for a mag 12 or larger which will be plenty. Going to make one end the overflow so I am having a piece of black acrylic cut.

I have to say that it was pretty nerve racking drilling the tank.  It was very easy and just took a very methodical approach to it.  I also watched all the videos on you-tube demostrating how the process.  

Just scary as crap not knowing for sure if the tank bottom was tempered or not. Spoke with three people(manufaturer) that said it was ok to drill.  


Any thoughts??

[fishlady]

Re: 2" overflows & returns questions

my thoughts are this Chris...
better you than me with a drill in your hand....
good luck with that project....

oh and thanks for letting me play with the new babies...... .....loved it.....

and speaking of babies......you wouldn't believe the shakin going on in my chimba colony now..... 8O
they weren't in there 30 minutes and the dance was on...... :dance:

i'll get some pics up for ya soon......
gorgeous indeed.....

[txfatcat]

Re: 2" overflows & returns questions

Glad to hear it. That  is going to be a great colony of Chimbas.  

Stacy is home now and wanted to say thanks for the gift.

[fishlady]

Re: 2" overflows & returns questions

oh ...don't mention it....
it was a gift to be able to play with the new wee one's for me.....
glad she's home.....if she needs anything and i can help surely just ask......