I drilled two 1/8" holes into my return line as siphon breaks. When I simulate a power outage, the holes get exposed and suck in air, but the return line doesn't stop flowing until the open end of the return sucks in air. I'm guessing that the holes arent introducing enough air to break the siphon but I fear adding more or larger holes will dump too much water volume into my overflow and hurt circulation. Finally where do most people point there return nozzles? Along the surface to help oxygenation or down to provide more even flow to the rest of the tank?

mine are pointing down, but they are also only about 1" below the water level when the return pump is running.

Mine point downward as well.


I had the same problem and it was becuse the hole was too small. Maybe you can drill a second ot third small hole at antoher location facing away from the overflow. This may give you enough airflow to brake the siphon.

HTH

Good luck.

John

Thanks for the responses, I'm going to add a third hole to the return line and see if that works. The way I have the return nozzles now I can't overflow my sump but the siphon holes are doing nothing.

Hi All

My returns (2 of them) point up to help keep surface boken up and flowing for gas exchanges. The openings are about 1/2" below the surface. I have two MJ mods that provide the in tank circulation.

Bonnie

i would say to make them a little bigger. they need to be big enough to suck in enough air to break the flow of the water being pulled into the lines.

just make sure if you do break up the surface water its not too much or you'll get lots of salt creep on everything.

....and check those siphon break ports often for algae, salt creep, anything that will block them and keep siphon. Sadly, my tank is dealing with a shag carpet....er...hair algae outbreak and I lost power in a snowstorm. Mrs. P was NOT happy with the salt water ring on her carpet ;)

Dave

Thanks for all the suggestions, the holes i drilled are brand new so they arent plugged up. I'm going to add a third hole and report on how that works. Sorry to hear about the carpet Dave, I can imagine the reaction you got.

I have gone the siphon break hole route, and you have to issues here to contend with. First, the holes will eventually become blocked, usually encrusting algae, unless you turn the system off on a regular basis and "exercise" the system. Worse, under pressure these holes, if not the perfect size, can throw bubbles into the system (if you make the mistake of drilling the hole above the starting water line. So, what to do? A $22.00 check valve will make all these issues go away. All the usual suppliers have them, and they work.

All the usual suppliers have them, and they work.

For a while....

IMO, I wouldn't put all of my eggs in that particular basket.

For a while....

IMO, I wouldn't put all of my eggs in that particular basket.

i agree, my return nozzles come in through a 3/4" bulkhead in my overflow and turn though the overflow top and aim down into the tank. my tank only drains about 1" - 1 1/2" of water from the display in a power outage.

i would place the returns just below the water level when the pump is on and make sure that your sump can handle the water volume that will drain when the power goes out.

do you have a pic of your overflow and sump ?? it would probably be easier to explain with a picture of your setup.

i agree, my return nozzles come in through a 3/4" bulkhead in my overflow and turn though the overflow top and aim down into the tank. my tank only drains about 1" - 1 1/2" of water from the display in a power outage.

i would place the returns just below the water level when the pump is on and make sure that your sump can handle the water volume that will drain when the power goes out.

do you have a pic of your overflow and sump ?? it would probably be easier to explain with a picture of your setup.

That is exactly how I have it setup right now. The siphon break holes dont work, but my sump can handle the water volume until the returns suck in air. Im leaving it alone because it works. Will probably just replace the return PVC tube that i drilled siphon breaks in (eliminate the unfucntional siphon breaks). Thanks for all the suggestions, of all the reefing forums i have found this is by far the best. It has the nicest and most helpful members possible, who are always willing to help. You guys make this hobby more enjoyable than it already is.

thanks, glad we could help. if you need anything else ... just ask !!

Don't worry im chock full of questions hehe. Now if I could only shut up my overflow line. Any votes for a ball valve on the overflow line? How about a reverse durso? Ive got a vinyl 1 1/4" hose for my overflow set at sump water level but am getting lots of bubbling noise.

i would just try putting an elbow on the end of it and aiming it at the side of the sump.

never, ever, ever, put a ball valve on the return for the purpose of dialing down the overflow (hello flood). If you want to slow down the overflow and quiet it down, you need to slow down the return pump. The best way is by using a smaller return pump, but diverting a portion of the pump back to sump is acceptable also.

I dont think the overflow has too much flow, rather the opposite. I have a lot of air coming down the overflow line. I'm going to try something like a reverse durso and report on how that works out. I'm also wondering about water flow and turnover rate in my tank. I'm turning over the tank around 6times/hr through the sump. How do I decide how many addtl powerheads to add to the display and where to place them? I was thinking of adding a koralia or two to the display, but need lots of advice.