Main Drains - Open or Closed?

[OntarioCanada]

it's my first year in house with pool, the company that opened the pool back in May left the gizzmo plugged in the second hole (for the pipe which goes to the 2 main drains (I have 2 drains with curved large covers to prevent someone from getting stuck to them so I know they are safe). I live in Ontario, Canada so in winter we have freezing temperatures.

My question is if the main drains should be left closed off even when the pool is open? I am assuming I should keep them open for better circulation and make sure the drains don't get clogged due to no water circulating through them, am I wrong?

 

[Jimrahbe]

OC,

You might get slightly better circulation with the main drain open, but not enough that you would even notice. When the main drain is closed, you get more skimmer suction, so it kind of balances out.

I have two rent house pools that do not have operating main drains and they seem to work just fine. The pool at my house has a main drain, but I normally run it at about 95% closed. I can't really tell any difference with the drain closed or opened. I open it about 5% just to keep a little water flow in it.

And just to be picky... You have two drain covers, but they actually go into one pipe leading back to your equipment pad, so you really only have one main drain.

Thanks,

Jim R.

 

[OntarioCanada]

OC,

You might get slightly better circulation with the main drain open, but not enough that you would even notice. When the main drain is closed, you get more skimmer suction, so it kind of balances out.

I have two rent house pools that do not have operating main drains and they seem to work just fine. The pool at my house has a main drain, but I normally run it at about 95% closed. I can't really tell any difference with the drain closed or opened. I open it about 5% just to keep a little water flow in it.

And just to be picky... You have two drain covers, but they actually go into one pipe leading back to your equipment pad, so you really only have one main drain.

Thanks,

Jim R.

Thanks, two drains covers going into one pipe halves the suction at the drain cover to reduce the changes of someone getting stuck/sucked at the bottom of the deep end.

 

[DrewLG]

Thanks, two drains covers going into one pipe halves the suction at the drain cover to reduce the changes of someone getting stuck/sucked at the bottom of the deep end.

No, it's a lot better than half the suction. Having two covers -- presumably far apart -- ensures that even if someone lays down flat on one of them and completely obstructs it, the other cover will remain completely open, and therefore all the suction will be at the open cover and there will be (approximately) zero suction holding the person down.

 

[OntarioCanada]

So regarding my original question, does fully opening the drain reduces the suction at the skimmer that much that it Negatively impacts surface cleaning or should I open the drain and try?

Most people keep the main drains closed?

 

[Jimrahbe]

OC,

In the big pic it does not really matter all that much. I personally like to see more suction at the skimmers, so that is why I run my main drain almost closed.

There is no absolute right answer here. If you want to run with the main drain open, go for it. Just don't expect to see some huge change from running with the main drain closed to running with it fully open.

Try both ways and see what works best for you.

Thanks,

Jim R.

 

[DrewLG]

So regarding my original question, does fully opening the drain reduces the suction at the skimmer that much that it Negatively impacts surface cleaning or should I open the drain and try?

Most people keep the main drains closed?

In your case, with the main drain and skimmer in series on a single suction line, you're unlikely to see any difference. Nearly all your flow is through the mouth of the skimmer (the path of least resistance) already.

But I think you should open the main-drain hole anyway, because that -- in conjunction with a working float valve in the skimmer -- will allow your main drain to provide a backup source of water for the pump, to prevent it from starving if the water level ever drops below the mouth of the skimmer.

 

[OntarioCanada]

In your case, with the main drain and skimmer in series on a single suction line, you're unlikely to see any difference. Nearly all your flow is through the mouth of the skimmer (the path of least resistance) already.

But I think you should open the main-drain hole anyway, because that -- in conjunction with a working float valve in the skimmer -- will allow your main drain to provide a backup source of water for the pump, to prevent it from starving if the water level ever drops below the mouth of the skimmer.

That’s a good point when when the water level goes down which has happened a few times

 

[OntarioCanada]

Thank you for all the replies, I am going to open it tomorrow and see if makes anything worse. If not then bit more water circulating from deep is probably better.