Plug main drain or leave it?

[apricity]

Bought a house last year with an empty pool. Getting it replastered and was wondering if we should get the main drain plugged? Pretty sure the piping is old 1.5” copper but not 100% sure. Don’t really want to pay $375 for pressure testing. If we don’t plug it now and it leaks, is it hard to plug it after filled with water? Pool is ~25,000g with one skimmer and 2 returns.

 

[Oly]

My main drain is plugged and I see no down side.

 

[zea3]

Hi, welcome to TFP! You don't have to have a main drain to operate the pool. I would go ahead and plug it.

 

[Pool_Medic]

Plug it, Venturi doesn’t work. Had it been plumbed to pad, keep it.

 

[Jimrahbe]

A,

I would plug it and plaster right over it...

Thanks,

Jim R.

 

[jonpcar]

I only see one suction line into your pump. I’m assuming that all your suction lines (main drain, two skimmers) run into that line somewhere underground? Plugging the main drain won’t necessarily fix an existing leak (if any) around that main drain area or in the piping from the main drain. I’d be careful and probably do a pressure test before deciding to cover over it...am I missing something by thinking that (others)?

 

[proavia]

$375 seems excessive to pressure test that one line. Maybe call around and get a few other estimates.

Since you have a single suction line into the pump, your main drain line runs to the skimmer first. If you plug the main drain in the bottom of the pool, also plug the end that is in the skimmer. This will totally isolate the main drain line. Most times, there will be 2 openings in the bottom of the skimmer - the one closest to the pool is usually the line to the main drain. If you abandon the main drain, plaster over it in the pool bottom for a cleaner look.

 

[apricity]

$375 seems excessive to pressure test that one line. Maybe call around and get a few other estimates.

Since you have a single suction line into the pump, your main drain line runs to the skimmer first. If you plug the main drain in the bottom of the pool, also plug the end that is in the skimmer. This will totally isolate the main drain line. Most times, there will be 2 openings in the bottom of the skimmer - the one closest to the pool is usually the line to the main drain. If you abandon the main drain, plaster over it in the pool bottom for a cleaner look.

You are correct that the main drain runs to the skimmer first and I hear you on getting it plugged at both ends to isolate it. $375 was actually to pressure test all the lines. Never really considered just testing the main drain to skimmer line, could check into that. Just trying to avoid unnecessary cost and potential problems if there is no real benefit to having the main drain.

Never owned a pool before but only things I've heard it's good for so far is if the water line falls below the skimmer, then the pump could still pull water via the main drain. Also have heard conflicting opinions on it helping circulate water at the bottom of the pool. Have also heard some robot cleaners can get stuck on the drain covers. Also curious would keeping the main drain help or hinder head pressure?

 

[Killer95Stang]

Are you getting new equipment as part of your remodel? That filter is a considered a pressure vessel which could explode and cause damage or harm. If you look at it closely, the fiberglass on the top of the filter is litterally falling apart. Also, a switch to a two speed or variable speed pump would save you a lot of money. Also, all that needs to be placed on a proper equipment pad and not just sitting on dirt suspended by the piping.

Just noticed, all your pressure lines are connected or repaired with No-hub type fittings, which are not intended for pressurized systems. They are used for drain lines, like the kind under your sink.

 

[apricity]

Are you getting new equipment as part of your remodel? That filter is a considered a pressure vessel which could explode and cause damage or harm. If you look at it closely, the fiberglass on the top of the filter is litterally falling apart. Also, a switch to a two speed or variable speed pump would save you a lot of money. Also, all that needs to be placed on a proper equipment pad and not just sitting on dirt suspended by the piping.

Yeah getting a new filter for sure. Probably a Pentair FNS D.E. filter, but still trying to figure out if it's ok to oversize the filter to say 48 sq ft, 96GPM with D.E. (Think the piping is 1.5" so with lower flow rate due to head pressure issues (looks like I should stay around 45GPM?) will I have problems with D.E. pooling at the bottom instead of coating the grids? The current pump is actually newer than the rest of the equipment: a two speed 1hp and I flipped it on real quick. It does run, but hard to test with no water. So I might wait to replace until later. For equipment pad you mean something like concrete or pavers? Thanks! Will take all the advice I can get.

 

[Killer95Stang]

oversizing a filter is typically never an issue. It just allows you to go longer between cleanings.

Right now you could either take some 2 x 4's and frame out a decent sized pad, then with a few bags of quikrete get it all done within a day... or you can buy / order a composite pad from a pool store, amazon.. etc. I don't like the paver idea, because once all the pumps and filter are rigidly piped, movement of the ground between each piece of equipment can cause stresses on the piping leading to failures. Better to have everything on a level ground.

 

[Soupy]

I don’t know why you would plug it unless you know there’s an issue with it. I use mine all the time, I don’t get strong circulation on the deep end without it.

 

[apricity]

I don’t know why you would plug it unless you know there’s an issue with it. I use mine all the time, I don’t get strong circulation on the deep end without it.

Does your main drain pipe up through the skimmer and you still get strong circulation with it? You're right I don't know there's a problem, but if I leave it and there is a problem will it be a huge hassle to plug once the pool is filled?

 

[Soupy]

My main drain has a separate line back to the pump. So not exactly the same setup as yours.

If i needed to plug it, I’d probably use an expanding rubber plug. I’m not sure why that wouldn’t hold up long term, takes minutes to install or remove.

 

[Pool_Medic]

Soupy, the OP doesn’t have a dedicated line from the pad to the main drain.

 

[mikegmi2]

No advice from my side, but more so I just wanted to comment that my main drain is plugged...and now I understand why it is. We bought a house with a pool this year, and the main drain plumbing coming into the pool house has written on it "Plugged, keep valve closed". I never understood why someone would just abandon the main drain because it seemed important to me, and if it was plugged with debris, why not just get it blown out and working again? But now I get it...there is likely a leak somewhere and rather than digging up the pool to fix, just plug it and rely on the skimmer lines. My pool has 3 skimmers, so that plus a pool robot for the bottom does the trick.