three4rd Posted August 13, 2009 Report Share Posted August 13, 2009 Hi, Sorry about the title....meant to say DE filter! I've been a pool owner for 20 years and just maybe noticed this, but - having just gotten a new pump (which does seem to have pretty strong water agitation inside the strainer basket) as well as all new plumbing between pump inlet, pump and filter, and filter to return line- my DE filter tank seems to accumulate air. I can bleed the air-relief valve, and then a few hours later I can open it up again and more air comes out before I get a stream of water. And, when I let the water stream run it seems to go in spurts and with an interrupted flow - just like running a spigot that has alot of air in the pipes. Is this something to be concerned about? The technician who did the work said that it's not unusual to have a filter tank get some air in it even though it's been bled at the valve. Some internet pool info I've been reading, however, cautions against letting the air build up inside a tank. I don't recall having this problem before, but then again except for after backwashing/cleaning the DE grids, I've never really bothered with the air relief valve much at all. Am I just being overly paranoid? I have had all sorts of plumbing problems that were done by a poor technician recently that resulted in fernco couplers blowing off that would have emptied my pool had we not been home! So maybe now I'm looking for problems......it's just that I don't recall this amount of air getting in the tank. Any suggestions? I've mentioned it to the new tech that maybe there is a suction-side leak that is drawing air, but he didn't think so and said that it's nothing to worry about to have some air in the tank. What about when we go away from home for a period of time, though? Won't it keep building up??? Thanks, three4rd Quote Link to comment Share on other sites More sharing options...
Pool Clown Posted August 14, 2009 Report Share Posted August 14, 2009 The technician who did the work said that it's not unusual to have a filter tank get some air in it even though it's been bled at the valve. Maybe he didn't want to re plumb the inlet side again. Am I just being overly paranoid? No I have had all sorts of plumbing problems that were done by a poor technician recently that resulted in fernco couplers blowing off that would have emptied my pool had we not been home! He cut all those out right? So maybe now I'm looking for problems......it's just that I don't recall this amount of air getting in the tank. Don't be afraid to question your tech about his practices (in a non-confrontational way of course). Any suggestions? I've mentioned it to the new tech that maybe there is a suction-side leak that is drawing air, but he didn't think so and said that it's nothing to worry about to have some air in the tank. What about when we go away from home for a period of time, though? Won't it keep building up??? Your both standing there watching the air come into the pump and he didnt think there was a suction side leak? Maybe he thought the air was Cavitation and didn't want you to know he sold you a pump too big for the pipe. (I hope i'm wrong) Thanks, three4rd The problem with air accumulating in the filter tank is that when the internal bleed is not working, or can't keep up, the air bubble keeps getting bigger and it starts to reduce your filter area. Not only that, but that bubble is getting compressed while the pump runs, then when it shuts off, that bubble expands pushing the water back towards the pump and can drain the water out of the pump. The next morning, the pump may prime, or it may not (pump runs dry, heats plumbing, develops leak(s). It may be why you're pulling lots of air. Another scenario, This has already happened to your plumbing and you have a suction side leak. Now comes a new pump that may be drawing a little more water and that also means more air. Curious, Did you get a larger hp pump installed? Quote Link to comment Share on other sites More sharing options...
three4rd Posted August 14, 2009 Author Report Share Posted August 14, 2009 The technician who did the work said that it's not unusual to have a filter tank get some air in it even though it's been bled at the valve. Maybe he didn't want to re plumb the inlet side again. Am I just being overly paranoid? No I have had all sorts of plumbing problems that were done by a poor technician recently that resulted in fernco couplers blowing off that would have emptied my pool had we not been home! He cut all those out right? So maybe now I'm looking for problems......it's just that I don't recall this amount of air getting in the tank. Don't be afraid to question your tech about his practices (in a non-confrontational way of course). Any suggestions? I've mentioned it to the new tech that maybe there is a suction-side leak that is drawing air, but he didn't think so and said that it's nothing to worry about to have some air in the tank. What about when we go away from home for a period of time, though? Won't it keep building up??? Your both standing there watching the air come into the pump and he didnt think there was a suction side leak? Maybe he thought the air was Cavitation and didn't want you to know he sold you a pump too big for the pipe. (I hope i'm wrong) Thanks, three4rd The problem with air accumulating in the filter tank is that when the internal bleed is not working, or can't keep up, the air bubble keeps getting bigger and it starts to reduce your filter area. Not only that, but that bubble is getting compressed while the pump runs, then when it shuts off, that bubble expands pushing the water back towards the pump and can drain the water out of the pump. The next morning, the pump may prime, or it may not (pump runs dry, heats plumbing, develops leak(s). It may be why you're pulling lots of air. Another scenario, This has already happened to your plumbing and you have a suction side leak. Now comes a new pump that may be drawing a little more water and that also means more air. Curious, Did you get a larger hp pump installed? Hi... Interesting and good response! Thanks. In answer to a few of your questions and observations...when you watch the pump prime and start actually it does not look like there is any air. Then again, how can one tell this? All fernco joints are gone now (thank goodness). The guy is really good compared to the other tech who put the ferncos in. This new guy soldered in copper fittings that were threaded on the male end so that they screwed right into PVC fittings. (I have an old Anthony pool/filter with the copper no-hub fittings). How can I tell if the air valve is working right? It opens and leaves the air and water out. Then again....for the last few years I have had to turn it in as far as it goes rather than only having to turn part way..so it's maybe worn out and leaking? I do have a new one but didn't put it in yet. Could this be part of the problem? You may have hit something there - that I thought of as well- namely, that the problem already existed but is now more pronounced with the new pump. My old original Anthony pump lasted 20 years and probably wasn't putting out the water pressure that the new Hayward super pump does. He put unions in both at the pump inlet and coming out of the pump, where there were none before. I even tightened the union at the pump inlet. How can you tell if indeed there is a suction-side leak?? Certainly there is no water leaking anywhere. There is also a bit of foaming in the pool around the return line but I'm wondering if this is due to a high level of algacide. I really dosed it heavily because the pool was shut down completely for 2 days after the fernco connection blew. Luckily we were home when it went! The foaming comes and goes. When swimming, though, there is alot of foam, so I'm inclined to believe it is due to chemicals. The new pump is same HP as the old one...the other tech (whom I'll never use again) said we should keep it the same. Too bad these air valves don't automatically let out air when needed...it's strictly manual. I don't know what to do...but I think I'll question the tech again on Monday. I'm just worried about excess pressure build up. It doesn't seem, so far, that there is any trouble with priming but I'll look for what you described. Any other thoughts...please pass them along. Thanks again..... Quote Link to comment Share on other sites More sharing options...
Pool Clown Posted August 14, 2009 Report Share Posted August 14, 2009 The air bleed i'm referring to is inside the filter tank and has a screen on the end of it. Thats what happens, it gets dirty and causes the bleed to stop working. New pump is Probably moving a lot more water, even tho it's the same Hp. Pumps have come a long way in 20 years. Maybe since it's new, your present pool guy could exchange for maybe 1/2 to 1 Hp drop? Depending on what Hp this new one is. How much did the pressure increase on the filter when you switched pumps? You talked about how your new guy sweated new copper fittings. are these the pipes that come out of the ground? If you have had copper pipes in the ground for the past 20 years, that just may be your air leak. you may have pin holes where the water has eroded the copper (over time) and caused a leak. Quote Link to comment Share on other sites More sharing options...
three4rd Posted August 14, 2009 Author Report Share Posted August 14, 2009 Pool Clown, Thanks again for helping with my inquiry. Regarding the air bleed, inside the filter and attached to the DE grid assembly is a small tube, maybe 6-7 inches long (threaded fitting on one end where it attaches to the grids) and a small (not real fine) plastic screen on other end. Is this it??? I have no idea what this does......?? Is that tube possibly clogged? I've really never done anything with that save for squirting some water in it once in awhile when I backwash and hose off the grids. I just assumed you were talking about the manual air relief valve on the outside of the tank at the pressure gauge. Here's what I'm talking about: If you check out this link to my filter - is item #4 and 10 the bleed you are referring to. If not, any idea what this does ?? http://www.poolcenter.com/parts_filter_anthony.htm Pressure with the new pump is same as the old - I start at around 10-12 psi. Starting pressure used to be around 6-7 but after I added a heat pump last summer it went up. No reason was given me for why this is. I'm just assuming it's due to the extra length of piping to and from the heat pump. The copper fittings are only at the filter...all other underground plumbing is PVC. Thanks again...I'll keep an eye on it and look for any difficulties with priming and/or water being pushed out of the pump upon shut-off. Best, three4rd Quote Link to comment Share on other sites More sharing options...
Pool Clown Posted August 14, 2009 Report Share Posted August 14, 2009 Thats the bleed tube! Now, keep in mind that this only bleeds off the air that is accumulating in the tank, and if working, keeps the back flow from happening, but does not address the air leak problem. Quote Link to comment Share on other sites More sharing options...
three4rd Posted August 14, 2009 Author Report Share Posted August 14, 2009 It must be working, then, because I can shut off the system and no water even leaves the pump. It stays full until I start up again. I'm beginning to wonder if there even is an air leak at all? I don't really see air in the pump..but then it swirls around so fast in there and looks like bubbles are created. Doesn't agitated water of this sort generate some air? This pump is most definitely moving alot more water than the old one, which probably wasn't working all that well anymore. I guess the missing piece of info here is whether or not it is normal to always have some air in the tank or is it not normal? If I bleed the relief valve in the morning should there be more air in the tank by evening? Or, once bled, should only water come out everytime you open the valve?? Judging from the new plumbing - which is much better and tighter than what the other tech did, I can't see how there would be a suction-side leak. Where does the excess air go from that bleed tube? Quote Link to comment Share on other sites More sharing options...
Pool Clown Posted August 15, 2009 Report Share Posted August 15, 2009 It is ported to the clean side of the filter and back to the pool. Quote Link to comment Share on other sites More sharing options...
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