Silent and Failsafe Overflow System

[revjlw]

The wall of the overflow with the weir cut into it is only 1/4" from the ceiling of the acrylic tank. So, my goal is to not exceed the height of the overflow wall because that is precariously close to overflowing the tank.

Bean, may I send you some drawings and get you opinion on using 3/4" standpipes?

 

[Shock130]

I am going to use this overflow system on my 50 breeder, but have been playing with ideas for the overflow box, I just cannot decide... Would a coast to coast interfere with the lights to much. I will have 1 metal halide on each side of my MH. So in all the reflectors will span about 15.5 inches, and the tank is only 18 inches. How small of an overflow box can i get (how wide and how tall)?

Thanks!

Also how far apart should bulkheads be? Im guessing I will use 1"

 

[jb61264]

<a href=showthread.php?s=&postid=15239040#post15239040 target=_blank>Originally posted</a> by Shock130
I am going to use this overflow system on my 50 breeder, but have been playing with ideas for the overflow box, I just cannot decide... Would a coast to coast interfere with the lights to much. I will have 1 metal halide on each side of my MH. So in all the reflectors will span about 15.5 inches, and the tank is only 18 inches. How small of an overflow box can i get (how wide and how tall)?

Thanks!

Also how far apart should bulkheads be? Im guessing I will use 1"

I can help on this one as I had similar questions on my 75 build. I used 1" plumbing throughout (except where I split my returns to each side I reduce down to 3/4").

Distance between the bulkheads should be at least the distance of the diameter of the hole you are cutting. If you are cutting 1" diameter holes for your bulkheads, there should be at least 1" between them...it would be better to go a little more than that as a minimum distance...but you cold also split them evenly across the entire width of the overflow you go with.

I was able to get away with a 4" D x 4" W overflow box with the 1" plumbing and it works great...just enough room to remove the 90 degree elbows if needed.

As far as the coast to coast design...I don't think it will really interfere with your light...the overflow box is glass so there may be a little filtering but it would probably be negligible. The real decision for me whether or not to go coast-to-coast (which I didn't) was not wanting to see silicone on the side of my tank and wanting to provide room for my return plumbing at each back corner of the tank...I went with a 36" overflow box (my tank is 48").

 

[Shock130]

Jb61264,

Thanks alot for your help, I did not think about seeing the silicone and the side of the box from the side of the tank, so maybe i will go about 15-20 inches or somewhere around there.

Any more input would be great!

 

[jb61264]

<a href=showthread.php?s=&postid=15239703#post15239703 target=_blank>Originally posted</a> by Shock130
Jb61264,

Thanks alot for your help, I did not think about seeing the silicone and the side of the box from the side of the tank, so maybe i will go about 15-20 inches or somewhere around there.

Any more input would be great!

Go with as much as you can...ideally, having the coast-to-coast provides the optimum skimming efficiencly...mine is 75% of my tanks total width so although I'm not at the maximum skimming efficiency, it is still pretty good.

I guess the other advice I would give you at this point is to plan, plan, plan...measure three times and step back..look, then measure again before drilling your tank

Getting the overflow box level with your tank is very critical, so take some time to make sure that you get that right as well.

 

[Kbra]

great info thanks

 

[searey]

4000gph drain. is 3 1-1/2'' drains good and do i need to use2'' spaflex or 1-1/2'' spa flex?

 

[jb61264]

<a href=showthread.php?s=&postid=15242354#post15242354 target=_blank>Originally posted</a> by searey
4000gph drain. is 3 1-1/2'' drains good and do i need to use2'' spaflex or 1-1/2'' spa flex?

I would encourage you to read back through the entire thread to be sure, but I believe I read at one point where this type of overflow had been tested with 1 1/2" plumbing up to 3000 gph and handled things just fine. I believe another post indicated a friend that ran just two pipes with this design up to 3600 gph with no issues. The same post goes on to make that case that you could probably flow 8000 gph through the 3 pipe system.

The first three pages of this thread has some really good discussion on the topic...again I would strongly encourage you to read through it

http://reefcentral.com/forums/showthread.php?s=&threadid=1310585&perpage=25&pagenumber=1

 

[mr.wilson]

Hi Bean, I agree that your system is the best available and have used it for a few years on several tanks, upon your recommendation in another thread (Calfo overflow I think?). I have a few of questions.

1) Wouldn't it be more efficient to have the siphon ball valve at or near the end of the drain line instead of at the start? How do you keep a 1.5" drain line full of water and no air if the flow limiting ball valve is at the start of the siphon? I guess the main siphon line will purge air if the end is submerged in the sump where no air can enter from the bottom. Otherwise, gravity will pull the water down the siphon line faster than the valve will allow it to enter, and suck air up from the bottom. Perhaps my situations have been unique, as the displays have been on the main floor, with the sumps in the basement, and my flow rates are far less (only enough to feed the protein skimmer). One problem with having the valve at the end of the drain line is it's less convenient while you are doing the initial set-up (running back & forth to check).

2) I know you use a very high flow-through rate in your tanks, but wouldn't the siphon work more efficiently with a smaller 1" line or 3/4" in some cases? This would allow the friction of the smaller diameter pipe/hose to do the same job as the valve without reducing to such a small diameter in one location (cavitation & irregular shaped clogging point). I also think a gate valve is more accurate for fine tuning and less likely to clog than a ball valve. Once again, my applications have had 16' drops, so the siphon power is much greater than what you would get with a more typical 6' drop.

Sorry if these questions were covered elsewhere in the thread, I'll admit I skimmed through it Thanks again for sharing your design.

 

[Lowredranger]

I am having a problem with my main drain restarting the same suction after a power failure. The water level rises up and the main doesnt ever seem to catch back up. I switched my main from the secondary as the main was originally hooked up to the skimmer but i think the skimmers bubbles were affecting it but even now that it is straight from the box to the sump after it sucks air after a power outage i have to readjust it. Any help would be great thanks.

Jason

 

[BeanAnimal]

<a href=showthread.php?s=&postid=15247685#post15247685 target=_blank>Originally posted</a> by mr.wilson
Hi Bean, I agree that your system is the best available and have used it for a few years on several tanks, upon your recommendation in another thread (Calfo overflow I think?). I have a few of questions.

Thanks for the kind words Wilson

1) Wouldn't it be more efficient to have the siphon ball valve at or near the end of the drain line instead of at the start? How do you keep a 1.5" drain line full of water and no air if the flow limiting ball valve is at the start of the siphon?

The end of the siphon is submerged, so no air can get back in. The drop is not sufficient to allow the falling water to cause cavitation. Placing the valve near the END of the standpipe is certainly an option, but not a requirement on a short run. For long drop (to basement), the valve may need to be near the end of the pipe.

I guess the main siphon line will purge air if the end is submerged in the sump where no air can enter from the bottom. Otherwise, gravity will pull the water down the siphon line faster than the valve will allow it to enter, and suck air up from the bottom. Perhaps my situations have been unique, as the displays have been on the main floor

Yup, you got it. You answered your own question

One problem with having the valve at the end of the drain line is it's less convenient while you are doing the initial set-up (running back & forth to check)

Yup... a helper makes things easy. The nice part about the system is that once it is set... it is forget.

2) I know you use a very high flow-through rate in your tanks, but wouldn't the siphon work more efficiently with a smaller 1" line or 3/4" in some cases? This would allow the friction of the smaller diameter pipe/hose to do the same job as the valve without reducing to such a small diameter in one location (cavitation & irregular shaped clogging point).

For a lower flow rate, a smaller siphon can certainly be used. The open channel should still be as large as possible. It was easier to publish the design with a "common" standpipe setup for all (3) standpipes. If you start specifying pipe sizes for different flow rates and standpipe location, you end up answering exponentially more questions.

I also think a gate valve is more accurate for fine tuning and less likely to clog than a ball valve. Once again, my applications have had 16' drops, so the siphon power is much greater than what you would get with a more typical 6' drop.

Good gate valve are expensive and cheap ones are prone to leaking at the stem. For a large setup like yours a good gate valve is a great upgrade. As for clogging, the velocity through the valve makes that pretty much a non issue. The intake of the standpipe should be such that no single large object can pass into the standpipe anyway. The Reynolds number for a partially closed ball valve is actually not that bad compared to the same restriction is most gate valves.

Sorry if these questions were covered elsewhere in the thread, I'll admit I skimmed through it Thanks again for sharing your design.

Thanks for using the design and stopping in to provide feedback.

 

[kudora]

water tested my set up last night on my 40 breeder, some pics for those interested.



front

overflow(forgot to shim the tank last night before adding water to make it lvl)

sump layout

syphon and open channel

plumbing fts

questions or comments are welcome

 

[1DeR9_3Hy]

^^^ Well executed

How is the return pump noise with it mounted like that? I currently have mine mounted in the same way it there is always a small vibrating hum being emitted.

 

[kudora]

its not too bad but i will have to come up with something soon since it will bother me down the line. i was talking to tswifty today and might take him advise and fill silicone into eggcrate.

 

[VegasReefer]

If you want to cut down on return pump noise, replace one of your 45's with a section of Spa-Flex, and mount the pump on a small piece of silicone matting ( like a mouse pad that doesn't have anything on it ) the Matting will isolate it from the sump, and the spa flex will isolate the PVC keeping it from vibrating against the tank/ stand.

 

[augustasalty]

thanks for all the helpful information

 

[tonyespinoza]

beananimal - i'm a big fan of your approach and have used it successfully on my tank (and a new one i'm building now). i have a question for you on noise level for a different drain situation. i need to link two tanks that are at the same level (elevation). but the connecting plumbing needs to drop down below the floor level inbetween. there will be a return pump in the distal tank pushing water back to the display. in this case, would the connecting plumbing automatically convert itself to a siphon (since both tanks are at the same level?) or would there be much gurgling as the calfo-style drain sucks water in? flow rate will be reasonably high (around 2000 gph). thanks for any insight!

 

[troylee]

Bean....its sad to say your no longer with us........but I finally got my tank going and the overflow is great.....just in case you swing by to look.....

 

[VegasReefer]

Where did BeanAnimal go? I just realized the 'Moved ON" but didn't see anything about him not being here, or on his Bar and grill website.

 

[troylee]

Dunno where he went.....the moved on part means r.c. will no longer allow him to post....for what ever the case may be...