Main Drain - to Use or Not?

[BrianMars]

Hi - this is our second season in our new house with our in-ground 16 x 32 pool, and I have a question about using or not using the main drain on the pool.

The pool has a shallow end of 3 foot down to the deep end of 8 feet where the drain is. Per the previous owner, he says he used the main drain to circulate the heated water better to avoid cold spots. And per his recommendation, I capped the main drain with a winter cap at the end of last season, and so far this year I haven't taken it off yet. The "winterizer" cap is basically a drain cap with a rubber flap/flange cut to fit under it so it kind of seals off the bottom drain. The summer cap is the typical drain cap with open holes in it and no rubber flange/flap. But my experience from last year and this year is that I'm not encountering any terrible variation in water temperature anywhere in the pool...even in the deep end it's not bad.

So my question is - do I even need to take the winter cap off the main drain? I mean aside from the fact that I'm too lazy to dive down there with a screwdriver and try to swap it out, because I did that last year and it took me an hour of repeatedly diving to the bottom, floating away from the target, dropping the screwdriver, misaligning the screws and holes, etc. before I got it swapped out. Is there any harm to just leaving that winter cap on there? Or could it somehow long term hurt the plumbing of the pool?

Thanks for any advice -
Brian

 

[MattCarp]

Hi - this is our second season in our new house with our in-ground 16 x 32 pool, and I have a question about using or not using the main drain on the pool.

The pool has a shallow end of 3 foot down to the deep end of 8 feet where the drain is. Per the previous owner, he says he used the main drain to circulate the heated water better to avoid cold spots. And per his recommendation, I capped the main drain with a winter cap at the end of last season, and so far this year I haven't taken it off yet. The "winterizer" cap is basically a drain cap with a rubber flap/flange cut to fit under it so it kind of seals off the bottom drain. The summer cap is the typical drain cap with open holes in it and no rubber flange/flap. But my experience from last year and this year is that I'm not encountering any terrible variation in water temperature anywhere in the pool...even in the deep end it's not bad.

So my question is - do I even need to take the winter cap off the main drain? I mean aside from the fact that I'm too lazy to dive down there with a screwdriver and try to swap it out, because I did that last year and it took me an hour of repeatedly diving to the bottom, floating away from the target, dropping the screwdriver, misaligning the screws and holes, etc. before I got it swapped out. Is there any harm to just leaving that winter cap on there? Or could it somehow long term hurt the plumbing of the pool?

Thanks for any advice -
Brian

When my liner was replaced 4 years ago the installer got rid of the main drain needed new hydro valve and he thinks they are pointless and only another spot for a leak..... I have a 20x40. 8 foot deep pool and have never noticed any problems with cold spots. I only have 1 4x4 skimmer and the pool is Always clean. He said the water will circulate by itself that's just the nature of water.... I only have 2 returns and one is pointing down to move the Chems low.

 

[BrianMars]

Thanks - I guess some people like the option of having them, my buddy has a 20 x 40 with no main drain at all and it's fine. My water is also crystal clear since I switched to liquid chlorine (thanks to the TFP site!) and my chemicals are largely staying in balance. I just wanted to be sure it wouldn't harm anything by leaving that winter cap on there and never running the bottom drain.

 

[JohnT]

If a storm blows through while you are away and your skimmer fills with leaves, without a main drain your pump could be damaged from running dry before you get there.