all pvc overflow flow rates?

[coffeetwitch]

do i buy a contentious siphon overflow box from aquacave for 120 ish dollars that will flow 800gph or do i make an overflow?

how do i make something that will be 800gph like the box i can purchase for 120?

im sure most have seen this picture but it never mentions, or i cant find, flow rate.

if i have to build this thing out of 3" pvc to get 800gph, ill just spend the money for the aquacave option.



please help and i thank you

 

[coffeetwitch]

yeah more questions even before i get any replies

why does the portion inside the tank have to be the same length as the portion outside the tank?

i am also thinking that if i can flow 800gph through this, i will probably still use a lift pump on the nipple/barb on the top to help keep air from building up in the pipe to ensure i dont loose siphon on a power out.

 

[Rscomia]

The portion inside the tank and the outside do not need to be the same length my outside is twice the length as my inside if this actually effects the flow rate I have not checked that but my theroy was it gives the water farther to fall thus speeding it up and increaseing the flow

 

[coffeetwitch]

cool thank you for the input! mind if i ask what size pipe you have and what your return pump is?

 

[Rscomia]

Here is a link to the one I built http://www.aquariumadvice.com/forums/f20/diy-pvc-overflow-153636.html
I used 1.5 inch pvc and my return pump is rated at 1385 gph with 13 feet of head pressure

 

[coffeetwitch]

thats a lot of flow! so i shouldnt be too paranoid about this and just build this thing out of 1.25" and i will be fine?

mag-drive pump rated at 800gph at 4 feet. part of that flow will be diverted to the fuge so i guess only 600gph will reach the tank.

 

[coffeetwitch]

forgot my manners, thank you.

 

[Rscomia]

forgot my manners, thank you.

No problem just remember you can always put a ball valve in line to tweak your flow I actually have 3 in of them one in the overflow one in the return pipe and one in my pie going back to the fuge This is the one I mainly use to tweak mine by adjusting how much water goes back to the fuge versus the tank

 

[coffeetwitch]

i guess ideally i would like it to be able to handle little flow clean up to the return pumps full gph rating with out loosing siphon.

i guess i will run that exact test when i get it all up and going.

 

[Rscomia]

The only time mine lost siphon is during a water change once I drained it below the intake and it let all the water run out of my pipe so now before I change water I shut the vavle in the overflow to hold the water in Ive simulated power outages to check and since it never drains below the intake then it maintains siphon and as soon as the power comes back on it works like normal

 

[coffeetwitch]

cool thats good to know.

i saw a youtube vid of a guy saying he had to build another overflow because he wasnt getting enough flow. that vid is probably what has sparked my doubt.

you know how it goes, it only takes that one to ruin it for the rest.

Overflows - YouTube

 

[mrbee2828]

To your original question about buying or building, you should make that decision based on your wallet and your time. I think you can get the flow you desire in either choice with the right setup. Also, the PVC one will probably be louder than the box you're looking at. I don't know this for a fact, just from what I have read on the web about other builds.

I'll throw in a comment as a recent DIYer and some lessons learned. I'm still in the process of refining mine or trying to make some rework decisions. This is just from my POV so take it with a grain of salt. I have a video and some other stuff as well as a overflow thread here in this section. http://www.aquariumadvice.com/forums/f20/benjamins-55g-malawi-cichlid-build-166240.html I had a check valve leaking air whihc was killing one of my intakes too... another headache with DIY.

The thing I dislike most about my setup right now is trying to constantly match my overflow and my return. I'm always adjusting the dang valves trying to evenly match them and keep the water level in the sump above the pump intake as well as keep the water in the main tank high enough to quite the overflow. Because of my box design in the tank and the small design of the sump it's battle. Most likely my design flaw.

However, if I do turn off the valves to do anything, I have to adjust everything all over again. If I redid it I think I would do 2 vavles. 1 to act as a restriction to tweak my flow and the other as a straight on and off. That way I'm not trying to find that sweet spot forever after maintenance.


The other thing is where you want your water line and how much space you have in your sump. When the power cuts off you need space for the water from the return overflow PLUS the water in the pipes to fit in the sump. Again, with my design there isn't a whole lot of room for error. It's right at the rim when the power cuts out. This is also something I'm going to try and adjust by lowering my overflow edge and being able to lower the water in my tank some.

 

[coffeetwitch]

http://www.aquariumadvice.com/forum...ater-reef-with-fish-evolution-165050-156.html

scroll down to post 1554

thats what ive come up with. its basically a mess of alot of different ideals.

mrbee i ran accross your thread when i was searching for everything. what kind of flow are you getting through your twin setup?

 

[mrbee2828]

I honestly don't know but I think it's too much for the tank. I upgraded to a 1,300gph pump and I have a 5' 3/4" PVC pipe going up the back. That is fully opened with another hitting the refugium side just barely cracked open to divert a bit. I have my overflow cranked down about 1/4 of the way to what it could be doing. I honestly don't know how to measure it. I know the bubbles, plants and fish are getting a work out though I should do a video of it soon.

 

[coffeetwitch]

man im getting a lot of conflicting stories and reports on how much flow people are getting.

 

[coffeetwitch]

diy overflows - Oscarfishlover.com
Overflow Drain Calculator - .::AquariumPros.ca::.
DIY Overflow 101 - YouTube
DIY Overflow Box (DIY OVERFLOW PROJECTS)
DIY Sump and overflow Part 2 - YouTube

these are some inforitive links that i have found or that where shared with me. something that i never knew about is leaner overflow. its an interesting argument if you want to look it up.

im incorporating a 3" reducer on mine because of it.

 

[coffeetwitch]

k so i just did some testing in the bathtub. through my 1" pvc diy overflow i am getting 360 gph. any suggestions?

 

[mrbee2828]

What's the leaner overflow? I don't really have the time to watch both but the 2nd one was starting to make me sick anyway lol. Got a link? Google isn't turning anything up.

 

[coffeetwitch]

Linear overflow. Like how yours is set up with the big tube cut in half. That ledge that water flows over before it gets to your siphon tubes is the linear overflow. I'm on my phone until I get off work but if you have more questions I'll try to post a link to a better explanation than I can give. Some how it makes a difference in flow rate. If you've got time and the means, maybe google linear overflow explained. That's how I found the info.

Sorry if I misspelled it earlier or made it sound like a style of overflow.

 

[Rscomia]

quick drawing of what mine looks like behind the tank