Return outperforming overflows

B

betacrash

Guest
I have a 155 bow front that I just purchased. It came with two overflow boxes (I do not know how many gph they are, any way to find out?) and a ocean runner pump that is rated at 1600gph. When I bought it I noticed that he had another piece of PVC that he was using as a simple siphon overflow (he had it setup way ghetto). Well I set it up in the garage to test the overflows and get the plumbing started and I noticed after about 10 min that the tank was started to overfill. So do I need to setup a third overflow? If I put some sort of regulator on the pumps output could that damage the pump? Lastly, if I use a SCWD will that lower the gph that is being output? Thanks.
 
farmboy

farmboy

Active Member
How big are your drains? A one inch bulkhead is rated around 600 gph. Even 2 of these wouldn't keep up with that pump. That might explain the ghetto. . .
Any plumbing you add, including 90's and 45's, will lower your flow rate. I'm sure the SCWD would as well--not sure how much.
You could "T" the return line and run part of the flow back into your sump. Just valving off the return can work the pump too much. When you configure the system, you DON'T want the bottleneck to be the overflows. The pump should be. (cuts down on the mopping)
Hope that helps
P.S. Squid writes a LOT about plumbing. Search for some of his posts about overflows.
 
farmboy

farmboy

Active Member
Hey beta,
Did you find what you need to be "Moving on up" out of the ghetto?
I'll bet you've been reading some from Dr. Squid.
THis site is Great.
 
B

betacrash

Guest
I think it just comes down to me getting a smaller pump. No biggie. Not my favorite solution. But I just didnt want to have to deal with 3 overflow boxes. And I feel like the methods for lowering gph were just a stall method.
 
todds

todds

Member
Why not add larger gph overflows? I have been building them out of acrylic for some time with pretty good success. If you build or buy an overflow with a 1 1/2" outlet it should handle up to 1600gph.
 
B

betacrash

Guest
I'm pretty crafty, but havent tried any homemade acrylic projects (yet). Do you have any pictures of your overflows? Did you use U tubes or is it a weir style box?
you can email pictures (if you have any) to shawn.hines@gmail.com
 
B

betacrash

Guest
I would definitely appreciate it. By they way, how many gph do you get from your overflow?
 
squidd

squidd

Active Member
Beta...Which Ocean Runner Pump do you have...?
Is it a 1600gph rated pump or a 2400pgh rated pump that will do 1600 gph at 4' head...?
If it's a 1600gph pump, your probably only getting 1000 gph to the tank, and the problem is most likely in the "setup" of the overflows and U tubes...and their ability to drain the tank.
I'm running a Mag 18 , with two 1" overflows and no restrictions or diversions to "stall" flow...
 
B

betacrash

Guest
It is a 1600gph (Ocean runner 6500) I had a buddy bring over his overflow box (its a dual output box) but the U tubes and whatnot looked about the same as my setup and it looked like it was barely hanging on. I do not know what the gph of that unit was either. So anyway. We tried a slew of variations by running just his box, his and one of mine then all three. I did notice that mine do not have any type of standing pipe in the draid side of the overflow so I did not know if that could be causing a problem. :needhelp:
 
B

betacrash

Guest
Todds, great pics. Im going to get some acrylic tonight and try to piece one together.
Hey Squidd. Thanks for jumping in to help. I dont have a picture right now, but is the something obvious that could be slowing down my overflows? And would a miniature durso inside of my overflow slow it down or speed it up?
 
todds

todds

Member
if you need some help bending the acrylic I found some tricks that might help. If you eant some help call me on my cell phone.
 
B

betacrash

Guest
I figured it out. I was messing around with the overflows and noticed that one overflow was jetting watter and the other was not. I though i had an air bubble in my siphon so I bobbed the U tube up and down and noticed when it was up that the water gushed. So I propped up the U tubes with a 1" pipe and presto It is now keeping up. I guess I need to just lower my skimmer boxes to the the tubes a little more intake area. Im a dunce. After I got it all going I installed my mini durso pipes and it made it about 90% quieter but the flow was affected and was shortly back to almost overflowing. Well, I guess it will work as long as I like it loud.
Question for squidd: with all of these recent "problems" that I have been having I was on the virge of getting my tank drilled in the back for overflows and returns. If this option is available to me cheaply would you recommend it? Tell me what changes you would make to the design.
 
squidd

squidd

Active Member
Glad you found it...that was the "something obvious" that isn't always so obvious... :D
Having the "U" tubes too close to the bottom of the overflow chambers reduces flow conciderably...
Propping them up, lowering the box or cutting a 1/2" of the bottom of the tubes should cure it...
Far as "drilled tanks" I like them over the HOB overflows...(eliminate the "U" tube factor) , but and there are a couple ways to get it done...low as you have shown will work, (I have one of my tanks drilled in the back) but you may want to build an "overflow box" around the standpipe to maintain water level and promote surface skimming...
Or drill "higher" and set up a Weir Box...
For the returns...you will need to either go OTT (over the top) or incorperate an antisiphon break...or the tank will drain to the level of the (as shown) returns in a power out situation...
 
B

betacrash

Guest
Altight. First of all.....Todds, thanks for offering to be so helpful. Definitely one of the nicest guys on the board. Second.....Squidd, I'm most likely going to be getting the tank drilled this weekend. I am planning on drilling for the overflows as they are shown and making covers for the pipes by bending up some acrylic. I would like to get a good amount of flow since I am using the 1600gph pump (I know I will be only getting about 1000) and I would like to add some extra flow in the future. What size hole do I need to have drilled and what size bulkhead and what size pipe? And will I just connect the two returns with a pvc to and then run it to the sump? Last question (Im a liar) for the return, should I just run PVC up the back and then tee it off and put two spray bars on? Or will that constrict my flow too much? Thanks. -Shawn
:thinking:
 
thetrex

thetrex

Member
It sound to me that you pump is to big. I would got to a smaller pump and put a flow control valuve in line with the pump.
 
squidd

squidd

Active Member
Originally Posted by betacrash
... I am planning on drilling for the overflows as they are shown and making covers for the pipes by bending up some acrylic....What size hole do I need to have drilled and what size bulkhead and what size pipe?
>>> https://www.saltwaterfish.com/vb/show...14#post1195214 <<<
And will I just connect the two returns with a pvc to and then run it to the sump? Last question (Im a liar) for the return, should I just run PVC up the back and then tee it off and put two spray bars on? Or will that constrict my flow too much? Thanks. -Shawn
>>> Not sure what your asking here... :thinking: Two Loc lines or spreader bar outlets will still need OTT or at least above ordinary high watermark antisiphon or you will drain the tank...
:happyfish
 
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