tif Posted October 18, 2011 Share Posted October 18, 2011 Tonight I tried to get my DIY PVC overflow going but just couldn't get it dialed in. I made it exactly after this example: http://www.aquariumlife.net/projects/diy-overflow/120.asp The "T" is about halfway down the back of my Biocube 29. I know the "T" fitting dictates the water level in the tank, but since the Biocube has the false back, I thought it would compensate and still keep the water level in the display where it's supposed to be. I guess I was wrong. The problem I'm having is the water level in the display tank very slowly decreases below the desired level while the water level in the sump increases. The details of the system are: 29g biocube display 3/4" DIY PVC overflow with 3/4" clear PVC hose to sump 20H sump with 10" high baffles spaced 1" apart MJ 1200 return pump with no elbows, just 5/8" clear PVC hose to return to display 4ft. head height What I think needs to happen here are one or more of the following: 1) rebuild overflow so that the "T" fitting is higher up the back of the tank 2) replace the MJ 1200 pump with something stronger (maybe Mag 5?) with a ball valve on the outlet to "dial it down" if needed What do you think? This is my first time having a sump and overflow. I appreciate any advice offered! Link to comment Share on other sites More sharing options...
impur Posted October 18, 2011 Share Posted October 18, 2011 I have used one of these before, though a slightly different design. I think you are on the right track by raising the T. What is probably happening is that since the return pump is only ~250gph (minus head), and the 3/4" overflow can handle a little over 300gph, the water is able to drain slightly faster than the return pumping it back up. This happens in an instance where the overflow is below the desired water level. The same would occur if, for example, you had a hole drilled down toward the bottom of the tank acting as your drain. Raising the T will allow the return pump to push the water from the sump to the display, and once it reaches the water level you want (which is where the T should be) it will drain at the same rate it is being returned. Link to comment Share on other sites More sharing options...
tif Posted October 18, 2011 Author Share Posted October 18, 2011 Ok. Glad that someone agrees with my idea of raising the T fitting. This leads to a new question. I used PVC cement to seal the seams of the PVC overflow. Is it possible to break this chemical bond, reuse the fittings and just insert new lengths of PVC to raise the T fitting? I tried using a couple of pipe wrenches last night to break the bond to no avail. Any ideas here? I realize the fittings are cheap but I'm a "reuse it" kind of gal. Link to comment Share on other sites More sharing options...
impur Posted October 18, 2011 Share Posted October 18, 2011 No sorry, the glue for PVC actually melts the plastics together. Link to comment Share on other sites More sharing options...
tif Posted October 19, 2011 Author Share Posted October 19, 2011 No sorry' date=' the glue for PVC actually melts the plastics together.[/quote'] Thank you, Impur, for your help/advice! I know it forms a chemical bond, but thought there might be a way to break that bond. At any rate, I spend $5 on new fittings and made a new overflow and decided this time to not glue it before testing. I butted the T fitting up against the elbow coming over the side of the tank. This made water from sump flow into the display tank faster than the overflow could handle. So, I dropped it an inch and that seemed to do the trick! Now, I have to get after the vibrations of my MJ1200 in the sump. I'll take measurements of the pieces of my DIY PVC overflow and post them on my tank thread so that others may benefit from my trial and error. Link to comment Share on other sites More sharing options...
impur Posted October 19, 2011 Share Posted October 19, 2011 Great to hear!!! Glad I could help out. For the vibrations try putting an old mouse pad under the MJ. Works like a charm Link to comment Share on other sites More sharing options...
tif Posted October 19, 2011 Author Share Posted October 19, 2011 Great to hear!!! Glad I could help out. For the vibrations try putting an old mouse pad under the MJ. Works like a charm I like this idea, however, I have the MJ stuck to the wall of the sump. I don't want the MJ on the floor of the sump because in the event the overflow failed it would pump all of the water on the return side of the sump into the tank. So, I'm thinking maybe I can find an acrylic box (or make one) that I can then put a mousepad on and place the pump on that. Any ideas? Link to comment Share on other sites More sharing options...
impur Posted October 19, 2011 Share Posted October 19, 2011 Maybe i'm not following your setup......it seems to me that in the event of a power outage, whether the MJ was stuck to the wall, the bottom, or anywhere in your sump, the water will still flow from main tank to the sump until the siphon breaks. Or are talking about when the power comes back on? Do you have a picture you could post up? Link to comment Share on other sites More sharing options...
tif Posted October 19, 2011 Author Share Posted October 19, 2011 Maybe i'm not following your setup......it seems to me that in the event of a power outage, whether the MJ was stuck to the wall, the bottom, or anywhere in your sump, the water will still flow from main tank to the sump until the siphon breaks. Or are talking about when the power comes back on? Do you have a picture you could post up? You are correct in the scenario of a power outage. In my case, about 5 gallons of water would backflow into the sump which can handle about 9 gallons total in addition to the water already in the sump. I was referring to an instance where, say, the overflow becomes clogged somehow. Water would cease to flow into the sump, but the return pump would happily continue to pump the return portion of the sump dry if the pump were positioned on the sump floor. With the return pump positioned on the side of the sump, less than a gallon of water would be pumped into the display before the pump ran dry. I'd rather have a pump burn up than a flooded living room. I'll try to remember to take photos of the whole system tonight. Link to comment Share on other sites More sharing options...
Burningbaal Posted October 19, 2011 Share Posted October 19, 2011 You are correct in the scenario of a power outage. In my case' date=' about 5 gallons of water would backflow into the sump which can handle about 9 gallons total in addition to the water already in the sump. I was referring to an instance where, say, the overflow becomes clogged somehow. Water would cease to flow into the sump, but the return pump would happily continue to pump the return portion of the sump dry if the pump were positioned on the sump floor. With the return pump positioned on the side of the sump, less than a gallon of water would be pumped into the display before the pump ran dry. I'd rather have a pump burn up than a flooded living room. I'll try to remember to take photos of the whole system tonight.[/quote'] be careful about maintaining siphon. if the power goes out and it drains safely (so you say), what happens when the power comes back on? the return pump kicks back on...how will the water start siphoning again? Link to comment Share on other sites More sharing options...
tif Posted October 19, 2011 Author Share Posted October 19, 2011 be careful about maintaining siphon. if the power goes out and it drains safely (so you say)' date=' what happens when the power comes back on? the return pump kicks back on...how will the water start siphoning again?[/quote'] If you look at the 2nd photo in the link in Post #1, the airline is connected to the Venturi connection of a powerhead. This automatically restarts the siphon. Also, in that same picture, you can see the blue and yellow "U" which holds water when the siphon breaks which also allows for ease of priming. Link to comment Share on other sites More sharing options...
impur Posted October 19, 2011 Share Posted October 19, 2011 You are correct in the scenario of a power outage. In my case' date=' about 5 gallons of water would backflow into the sump which can handle about 9 gallons total in addition to the water already in the sump. I was referring to an instance where, say, the overflow becomes clogged somehow. Water would cease to flow into the sump, but the return pump would happily continue to pump the return portion of the sump dry if the pump were positioned on the sump floor. With the return pump positioned on the side of the sump, less than a gallon of water would be pumped into the display before the pump ran dry. I'd rather have a pump burn up than a flooded living room. I'll try to remember to take photos of the whole system tonight.[/quote'] I understand now. You could just build a platform with eggcrate or something to keep the pump up at that level, then use a mouse pad or something under the platform, or under the pump, wherever it might be needed. Heck even an upside down tupperware or something would work if its tall enough. We get milk from Costco, Kirkland brand, and the jugs are square in shape. You could cut one in half or however tall you need it..........just tossing out ideas. Just make sure to poke holes so water can flow thru it. Link to comment Share on other sites More sharing options...
Burningbaal Posted October 19, 2011 Share Posted October 19, 2011 got it...all makes sense to me! as for the vibration issue, either make a padded stand for it to sit on, or make it so the intake for the pump is pulling from not-the-bottom of the return section of the sump. if the opening of the intake plumbing is halfway up the sump's height, you could put the actual pump below the sump entirely and never pull any water from below the intake. Link to comment Share on other sites More sharing options...
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