Overflow Sump Flow

[mrbee2828]

So is the fact that the water is falling about 10" into the overflow "box" causing the bubbles? If those bubbles weren't forming then there would be less air in the pipe which would reduce noise and increase flow... I would think.

 

[scottayy]

There can be several points of noise.

One point is the water crashing into the overflow box, yes. Try adding water inside of the overflow box to bring the water level up. I would think it's coming in the box at the same rate it's going down the pipe, so you should be able to add water inside the box to bring the water level up. But don't bring it all the way up to the water level outside the box because you'll lose your surface-skimming effect then.

Another point of noise is the water entering the drain pipe. There can be gurgling and even toilent flushing sounds there. It's due to air and backpressure. If you google durso standpipe or hofer gurgler buster you can learn more about those DIY mods. (i installed a hofer gurgle buster.. was easy and now my pipe is 100% silent)

Also, the water moving down your tubes can create noise. It'll just sound like the bathtub draining or something. I haven't figured out what to do about this yet, but mine isn't that bad.

 

[mrbee2828]

In what appears to be a cruel twist of events, I have discovered that 1 of the check valves on my 2 returns is leaking! This is probably why I was thinking the flow wasn't as strong as it could be. After a quick replacement, I've had to open the pump valve all the way up now and dial the return down because it's crazy fast. And now, we're back to crazy *** loud! I'm ready to go buy a canister at this point lol.

 

[coffeetwitch]

CS Overflow - Overview and Installation - YouTube

pay attention at 2:10 for the vent tube. that little tube they insert helps silence it. put an o-ring there and adj up and down.

 

[coffeetwitch]

and again at 4:43

 

[coffeetwitch]

3/4" pipe can handle 660gph and 1.25" can handle 1500gph using this site GPM/GPH Flow based on PVC Pipe Size, ie, How much water can flow through Sch 40 Pvc Pipe Size 1/2" 3/4" 1" 1.5" 2" 2.5" 3" 4" 6"

I would definately upgrade the pump, most decent pumps have a valve on them so the flow can be regulated to suit the overflow pipe,remember using dual pipes has its risks if one pipe gets blocked and the flow is too great for the other 1 flooding can occur.

diy overflows - Oscarfishlover.com

this is not the only site that posts these numbers for flow. if you dont want to go to the site these are the number:

"below is a chart that give the gravity flow rates of various size piping

pipe size flow rates

3/4"; 330 gph
1"; 600 gph
1 1/4"; 910 gph
1 1/2"; 1300 gph
1 3/4"; 1800 gph
2"; 2350 gph
2 1/4"; 2960 gph
2 1/2"; 3650 gph
2 3/4"; 4450 gph
3"; 5280 gph

"

why there are these two different set of numbers i dont know.

 

[mrbee2828]

@Coffee? How would I vent mine given the setup if that's what you're suggesting? I don't know how that would help mine since it's not really the same configuration. My intakes face down.

 

[coffeetwitch]

I was thinking down the pipes on the outside of the tank through your caps. Where is the noise coming from? With everything that I've been reading, the more you run your overflow to capacity, the louder it gets. If the noise is in your spill over box then maybe get more water in it. Idk I'm learning as I go, and sharing info as I come across it.

My hope is we can learn off each other. Wish I was further along with my build to give hard answers.

 

[mrbee2828]

Oh right right. I've since stuck some valves in the caps I made there with airline tubing. That cut the gurgling 100%. My noise is in the actual box and by the spray bar. Filling the box up kills all the noise BUT what it does is overflow my very small sump with a power out. So I'm back to the very tight balance I spoke of. Again... newbie design. Without the refugium I would have more room to play with volume. I cut that wall down 1" to allow for some additional overflow. I think I'm going to cut some slots in there this weekend to bring it down even more.

On the spray bar, if you look at the plexiglass enclosure I made, I just put a folded towel over it and it muffles the sound pretty good. I am thinking about going up and getting some pipe insulation to wrap the down tubes in. That might kill some of the rush noise a bit too. Plus it will keep my water warm right?

 

[coffeetwitch]

Yes I saw your Spray bar. What would happen if you got rid of it and let the water just flow on the sponge then let your drip tray do it's job from there.


Have you seen my 75g build? When I had my "suction" pipe and "u" taller than my "t" on the outside of my tank, a simulated power out would suck all the water out of the pipe. The "t" is the siphon break. Maybe if you redesigned it so that the "t" on your rig was higher, say where you want your water level to be you can keep your spill over full (quiet) and not flood your sump.

 

[coffeetwitch]

It seems there are two ways to do DIY overflows. The way I went is this:



The way you need to correct to is this:

 

[mrbee2828]

I ended up taking the end off of the spry bar and it really helped increase the flow. I was amazed it was killing it so much. I'm planning on just drilling much larger holes and seeing if it will help distribute it more. My design doesn't come down ininto the center like most. It comes in from the back so I have to have most of that bar there. I might just cut it in 1/2 if the larger holes don't help and just let it spill into the middle of the filter area.

I don't know about the T. Everything is glued and I'd have to redo it all. That is if I'm understanding you right. It's almost a complete rework if I do that I think.

 

[coffeetwitch]

At this point I say it's a "have to do" situation. But!!! You can run what you have until it's done. PVC is cheap. Did you silicone your pipe or christy's red hot blue glue it?

I really think that once you make this change you will be much happier with the results.

 

[mrbee2828]

Some how I missed your reply with the sketch. I see what you are saying. I might just do this. I need to finish my canopy and get my moonlight done first before starting anything else over Thanks

 

[coffeetwitch]

Hope it all works out

 

[David S]

diy overflows - Oscarfishlover.com

this is not the only site that posts these numbers for flow. if you dont want to go to the site these are the number:

"below is a chart that give the gravity flow rates of various size piping

pipe size flow rates

3/4"; 330 gph
1"; 600 gph
1 1/4"; 910 gph
1 1/2"; 1300 gph
1 3/4"; 1800 gph
2"; 2350 gph
2 1/4"; 2960 gph
2 1/2"; 3650 gph
2 3/4"; 4450 gph
3"; 5280 gph

"


why there are these two different set of numbers i dont know.

I can appreciate what you are saying but the reference you have stated is just flow rates written on someones thread where as my link is a flow rate chart given by a company that sells pvc pipe.

 

[coffeetwitch]

I understand that. I have found that site too while looking for answers for myself. As previously stated, why are these two numbers different? How did the people that stated lower flow rate derive those stats? Why are the lower flow rates posted on multiple forum sites? Why are there so many people that say they are not getting the higher flow rates through their DIY overflows?

I'm not saying anyone is wrong or suggesting anyone is better than another. I'm just asking why, and passing along caution.

 

[David S]

You need to add all the restrictions within the pipe run as well,people who use the diy overflows should take into account the restrictions a 90 degree bend has on flow,long radius bends should be used in all applications to reduce any restrictions,maybe this is how they come to those flow rates,I'm not sure.there are sites which you can work out the flow rate of pvc pipe with formula's,I use the site stated because my drain from the overflow is made with 1" hose so I dont have any restrictions like pipe bends.