rgoodwill Posted October 20, 2011 Share Posted October 20, 2011 Hi guys, I am in need of assistance from someone who is good with pvc/overflow projects. Basically, I have my whole pvc overflow system set up and it works perfectly. Once the water balances in the tank the cycle is flawless. I have put in all sorts of fail safes like siphon breaks but there is still one issue that I cannot seem to understand why it is occurring. If I do something to throw a hitch in the system to test the fails safes a problem occurs. Lets say I turn the pump off; next, the overflow would empty the tank up until the water does not reach it. Then if I turn the pump back (say the electricity went out and then came back on) the pump begins to pump water back into the overflow but once the overflow is full of water again it does begin to actively siphon water down again and thus the tank would simply overflow. There are two things that I am thinking are contributing to this; one, I did not drill a hole in the top of the overflow loop where you would normally put airline and maybe a air pump. When I made the overflow I was under the impression that this was only for ease of starting the siphon. In reality are you supposed to have that airline running all the time? Second, could the overflow design just be fault and for some reason not re sealing the siphon effect when the water raises again? The siphon works great when the water gets a little low but not once it drops all the way below the overflow. If it helps I can upload pics in order to illustrate this better. Thanks for any help you can provide. Sic' em. Quote Link to comment Share on other sites More sharing options...
joshgabel Posted October 20, 2011 Share Posted October 20, 2011 pics would be good or at least the type of overflow you have. Quote Link to comment Share on other sites More sharing options...
rgoodwill Posted October 20, 2011 Author Share Posted October 20, 2011 So right where the pipe goes into the other side of the tank is often where I see people put a check valve and then put airline tube and then a air pump. I do not have this yet and I am not certain if that is causing the overflow to not reseal. Any ideas what is causing the pipe to not reseal? Thanks Quote Link to comment Share on other sites More sharing options...
rgoodwill Posted October 20, 2011 Author Share Posted October 20, 2011 update: I drilled a hole into the top and added a check valve and some airline tubing and this did not work to prime the siphon. So either I did the check incorrectly or the design is faulty. Any help would be great. Thanks Quote Link to comment Share on other sites More sharing options...
rgoodwill Posted October 20, 2011 Author Share Posted October 20, 2011 here is a pic of the airline I added I think I placed it correctly Quote Link to comment Share on other sites More sharing options...
medi Posted October 20, 2011 Share Posted October 20, 2011 From the pictures it kind of looks like your tank is not drilled and you are trying to make a siphon style overflow out of PVC. Am I correct with what I think I see? Can you take a pic from the side or back straight on so we can better see what is going on? If this is a siphon style overflow and a newly setup tank then my main recommendation would be two things. First, find out if your glass is tempered. If it is not the proceed on. Second, drain the tank and drill it. That will save a lot of headaches in the future. Drilling tanks is easy and only takes a small amount of time. You can install a small overflow box on the back that will never fail and look great. I wouldn't recommend the use of check valves to prevent overlows in your sump. They can and eventually will fail. All it takes is for a small piece of trash to hang up on the inside and not let the valve close. Instead you should install a sump that is large enough to hold enough water so if every fail safe failed you still would not end up with a wet floor. Also, I think you may have already done this, but just in case you haven't you can drill a small hole in the wet side of your return to create a siphon break. Just make sure you do it on the bottom of the pipe so you don't end up with a water jet shooting straight up out of the tank. Quote Link to comment Share on other sites More sharing options...
rgoodwill Posted October 20, 2011 Author Share Posted October 20, 2011 Quote Link to comment Share on other sites More sharing options...
rgoodwill Posted October 20, 2011 Author Share Posted October 20, 2011 I can't drill my tank because its already pretty established. I do have several siphon breaks to keep my sump from overflowing. The issue here is that if the power goes out and comes back on then the sump pump would begin pushing water back in the tank. The problem is that then the overflow does not begin siphoning again. I am trying to figure out how do people get their overflows to begin siphoning again once the siphon has been completley broken. I just added a check valve and airline tubing today but it is very unclear if people are attaching some kind of powerhead in order to constantly resiphon the overflow if it was so lose the siphone. Quote Link to comment Share on other sites More sharing options...
rgoodwill Posted October 20, 2011 Author Share Posted October 20, 2011 I am also wondering is the problem that the pvc loop at the top is not on an even level with the loop at the bottom is that required for the siphon to start up again? Quote Link to comment Share on other sites More sharing options...
medi Posted October 20, 2011 Share Posted October 20, 2011 Sorry I can't help you there. I have never trusted a siphon system. Just too much can fail, and in my past if it can....it will. The wife usually doesn't appreciate that either. Quote Link to comment Share on other sites More sharing options...
joshgabel Posted October 21, 2011 Share Posted October 21, 2011 I am with medi on this one.. you can very easily drill a half full tank. just make sure your pumps and or skimmer is off. Quote Link to comment Share on other sites More sharing options...
rgoodwill Posted October 21, 2011 Author Share Posted October 21, 2011 Okay i will look into that thanks guys! Quote Link to comment Share on other sites More sharing options...
DerrickH Posted October 21, 2011 Share Posted October 21, 2011 Or just get a HOB overflow box that does all of this for you. Seems like a hell of a lot less headache. Quote Link to comment Share on other sites More sharing options...
polarbear Posted October 21, 2011 Share Posted October 21, 2011 (edited) im not an expert at this either, however, it looks like to me that the PVC pipe that you are using inside the tank is not long enough to start a siphon back up once the water flows into it. If you made the initial drop out of a longer piece of PVC pipe it might start the siphon back up. Edited October 21, 2011 by polarbear Quote Link to comment Share on other sites More sharing options...
polarbear Posted October 21, 2011 Share Posted October 21, 2011 (edited) . Edited October 21, 2011 by polarbear Quote Link to comment Share on other sites More sharing options...
rgoodwill Posted October 21, 2011 Author Share Posted October 21, 2011 Thanks polar bear I am going to try it out and I will let you know Quote Link to comment Share on other sites More sharing options...
rgoodwill Posted October 21, 2011 Author Share Posted October 21, 2011 Thats a negative on the idea, but I figured out what the problem is for people with the same problem. I have searched all over the web and havent found many people who can get theres to re seal the siphon after the water has dropped completley below it. The only way to fix this from what I have seen is adding a small powerhead to the airline tubing that is constantly pulling water. This fixes the issue because if the pump turns back on then so will the small powerhead and the siphon will reseal. The question now is where can I find very small powerhead. Thanks for the help everyone. Quote Link to comment Share on other sites More sharing options...
rgoodwill Posted October 21, 2011 Author Share Posted October 21, 2011 I found the solution you need a small pump called a AQUALIFTER. This can be connected to the airline hose to always reseal the siphon in case of a power outage. Thanks for the help everyone. Quote Link to comment Share on other sites More sharing options...
(Bio)³ Posted October 22, 2011 Share Posted October 22, 2011 now what happens when one of your two pumps fail? Quote Link to comment Share on other sites More sharing options...
medi Posted October 22, 2011 Share Posted October 22, 2011 A little thing called a flood! JK well sorta... I'm glad you got it all figured out. Quote Link to comment Share on other sites More sharing options...
rgoodwill Posted October 23, 2011 Author Share Posted October 23, 2011 well interestingly enough my return pump is quite old. I would think for most people this would be a bad thing, but for me it limits my risk even more. The small aqualifter is brand new and has an external filter so the chance of failure is relatively low. On the other hand, the chance of failure with my return pump is fairly likely. If the return pump fails the return line is equipped with a siphon break which will not cause a flood. The only possible way to cause a flood under any circumstance is if the power was to go out then turn back on and then during the short 30 second period that it takes for the aqualifter to reseal the siphon for the aqualifter to randomly fail. If the aqualifter fails at any other time then it is okay because the overflow has an active siphon. The chance of there every being a flood is incredibly small. Quote Link to comment Share on other sites More sharing options...
chippwalters Posted March 18, 2012 Share Posted March 18, 2012 I have built one of these mame style overflows in my tank and it works perfectly. First off, I'd recommend setting your U-traps to the same height dimension inside and outside. The length of your outside U-trap as shown is much longer than the inside U-trap and I suspect is siphoning off all the reserve from your inside U-trap. Next, add a check valve and Aqualifter pump and keep them running continuously sucking out any air that might enter the system. I assume you did a good job of cementing all the joints? Lastly, in order to prime the first time, remove the cap from your vertical clean out tube and fill with water. The Aqualifter will not prime your siphon, but it will keep it from losing the siphon-- assuming all else is setup correctly. And of course be sure to position your pump high in your sump and leave enough head room in your tank to handle excess return volume in the rare case the siphon quits for whatever reason. Burning up a sump pump is less expensive than cleaning up gallons of saltwater dumped in a carpet. And a float switch can also keep a sump pump from burning up as well. HTH. Quote Link to comment Share on other sites More sharing options...
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