I considered converting my main drain to a return for a little bit, but a bunch of reasons kept me from doing so and I'm glad I did. It's a convenient way to drain the water that you'll have to figure out one way or another otherwise. Just pushing water through a hole back into the pool isn't a good return. I used to just think holes==returns==good circulation but it's more complicated than that.
My pool is around 40 years old. The builder had an excellent reputation from what I hear but he's dead now and I don't know if anyone maintained his business or if they'd be as good as he was reported to be. I will say this: I have only one main return and one little return in a kidney alcove. I get fantastic circulation and never get debris buildup. When I dug the pipes up to redo a bunch of stuff at the pad, some of the lines confused me with their sizing and placement but the things is that it works and works well. A main drain converted into a return is going to be pushing against a *lot* of water and isn't going to be directed anywhere but in some diffused area around the bottom of the pool. To the extent that it would do anything it would likely do just as much going up as down (meaning, if it's actually going to increase the circulation by directing water *into* the pool, it should do just as well directing water *out of* the pool. That said, the literature I read indicated main drains don't do much by way of circulation.
What they do do, however, is allow you to drain water below the skimmer and if your water falls below the skimmer your pump won't burn out. In any case, even before I fixed up so much of what was wrong with my pool the shallow end (which doesn't have any returns closer than 35-40 feet) sparkled like diamonds so I don't think that returns have much to do with the sparkling of my water.
I have young children and I really went back and forth on the danger of my main drain under 9 feet of water. Based on what I know about how law is created, moral panics, and really juicy examples that tend to capture the public's and lawmakers' attention I concluded that I'm probably just fine with my main drain. I do know that one kid was killed by a drain but I haven't researched it out much beyond that to learn how many others were killed but it is the nature of law and public opinion that sometimes a danger can seem very real and more pressing than statical data would conclude.
My pool is around 40 years old. The builder had an excellent reputation from what I hear but he's dead now and I don't know if anyone maintained his business or if they'd be as good as he was reported to be. I will say this: I have only one main return and one little return in a kidney alcove. I get fantastic circulation and never get debris buildup. When I dug the pipes up to redo a bunch of stuff at the pad, some of the lines confused me with their sizing and placement but the things is that it works and works well. A main drain converted into a return is going to be pushing against a *lot* of water and isn't going to be directed anywhere but in some diffused area around the bottom of the pool. To the extent that it would do anything it would likely do just as much going up as down (meaning, if it's actually going to increase the circulation by directing water *into* the pool, it should do just as well directing water *out of* the pool. That said, the literature I read indicated main drains don't do much by way of circulation.
What they do do, however, is allow you to drain water below the skimmer and if your water falls below the skimmer your pump won't burn out. In any case, even before I fixed up so much of what was wrong with my pool the shallow end (which doesn't have any returns closer than 35-40 feet) sparkled like diamonds so I don't think that returns have much to do with the sparkling of my water.
I have young children and I really went back and forth on the danger of my main drain under 9 feet of water. Based on what I know about how law is created, moral panics, and really juicy examples that tend to capture the public's and lawmakers' attention I concluded that I'm probably just fine with my main drain. I do know that one kid was killed by a drain but I haven't researched it out much beyond that to learn how many others were killed but it is the nature of law and public opinion that sometimes a danger can seem very real and more pressing than statical data would conclude.
