Flow rate for 1" PVC overflows

[Bosa]

From reading several threads about the DIY PVC overflow it was mentioned that a 1" PVC overflow can handle about 600gph or was it 300gph...correct me if i'm wrong please.

When I tested the 1" overflow i made for my 29 gal, I put it in a bucket and got the siphon started and just had the water hose filling the bucket, i got to the point where the valve on my water hose was completly open i don't know exactly how much gph was coming out from the water hose...but it was alot of water!

I recently bought a quiet one 1200 which is rated at 296gph and built a 1" pvc overflow, i'm pretty sure that combination is going to be ok for a 29gal, I plan on setting up Dual 1" pvc overflows for a 180 gal, now does it mean that the max around 1000gph and i would have to get a return pump that pushes no more than 1000gph

 

[CHOMPERS]

The number that is most often regurgitated is 600gph. There are a number of factors that widely effect the hydrology of an overflow, so this number is only an approximation. Also, as you approach the maximum flow rate, weird things will start to happen (most common is sucking air and surging). You are fine in the 300gph range.

 

[nfored]

The number that is most often regurgitated is 600gph. There are a number of factors that widely effect the hydrology of an overflow, so this number is only an approximation. Also, as you approach the maximum flow rate, weird things will start to happen (most common is sucking air and surging). You are fine in the 300gph range.

600 with the DIY from the sticky is unlikly IMHO, I have 2 of them, and if I cap one and set the return pump down to 350 GPH the single overflow can't keep up. Maybe I am just dumb and didn't build something right, but I guess that the flow is closer to the 250 - 300 GPH. I have messured the flow of the retun line several times its pumping 320 - 350. Now im sure some of the Pro's out there could have got this thing closer to the 600 mark but that just seems a bit high to me.

 

[CHOMPERS]

I had set up a test rig and like you, had gotten a max flow in the 300gph range too. And like you said, some folks here have reportedly achieved 600gph. Rallysman did and I don't doubt him in the least.

The DIY overflows are powered by the syphon force that is determined by the distance from the water's surface to the placement of the Tee. Tall tanks in the 24"-30" range are more likely to reach the 600gph mark. Short tanks like a 20g long don't stand a chance.

 

[FSM]

I have a quietone 3000 and it works fine with a single 1 inch overflow. Are you talking about a drilled tank, or an overflow box?

 

[japes]

I'm getting around 600gph through 1" pipe using a PVC overflow, if the overflow uses a siphon to get the water to the sump it will work much quicker, depending on how it's designed. A normal gravity fed overflow (drilled at water level) will be slower.

 

[Bosa]

Thanks everyone! I live on the second floor and I want to learn from everyones experiences as much as possible so i can get it right the first time and not have angry wet downstairs neighbors

 

[CHOMPERS]

Do your R&D in the bath tub so that any leaks, floods, or spills will go down the drain. You can have as many failures as you need and it won't matter

 

[FishInTheFort]

Yes, thanks. Even thou it's years later, this information is still very helpful to those of us setting up our first big tank. I'm going from a 55 gal. to my new 180 gal.

 

[jcardona1]

Old thread, but for what's it's worth, I'm draining a 1017gph using a 1" Durso standpipe, and 1.5" for a 3400gph pump. It may be a little different using the DIY overflows though, so take it with a grain of salt.