Questions on Drains and Valves in Preparation of Partial Drain and Refill of In-ground Pool

MrLeadFoot

Well-known member
Sep 2, 2019
55
Sacramento, CA
Not sure where I should have posted this, so Mods, I apologize if you have to move this to the proper board.

I am trying to get a good understanding of how all my pool equipment, plumbing and valves work in preparation for a partial drain and refill, as has been suggested by experienced members on this forum.

My pool has two skimmers, one at the deep end and one at the shallow end, each of which has a black Jandy valve in close proximity to it on the outside of the aggregate "deck" (I think that's the term for the area around the pool), and a dedicated suction port on a wall between the shallow and deep ends. The pool has what looks to be like a drain on the bottom of the deep end, as well as another big covered hole that looks like a drain on the wall of the pool near the skimmer at the shallow end. I have a standard single-speed pump, pump basket, and paper-cartridge filter that has a big drain plug on the bottom of the filter housing. There is another black Jandy valve near the pump and filter equipment.

I have not been able to determine exactly how the valves near the skimmers work. Although I have used them to adjust flow to the skimmers, they don't seem to work as independently from each other as I would have thought. For example, when I turn the valve near a skimmer, while flow to that skimmer indeed increases or decreases, flow to the other skimmer seems to also be affected in one way or another. What am I missing here? :unsure:

I have also never been able to figure out how the drain on the bottom of the deep end works, or what the thing that looks like a drain on the shallow-end wall actually does. Can someone please enlighten me here? Do the valves near the skimmers affect the drains, if both of these are indeed drains?

For what it's worth, my skimmers have two holes below the baskets. One of the holes has suction when the pump is on, and the other has no flow either way, thus looks like a scary movie, in that it seems to go down into an abyss with no way out. :eek: Over the years I've often wondered if the unknown (to me) hole in the deep end skimmer leads down to the drain at the bottom, and I'm supposed to have some kind of u-pipe that connects the suction hole in the skimmer to that unknown hole, so when I want to use the bottom drain, I plug the u-pipe into the holes and the bottom drain would then suck up into the skimmer line, but that's just a guess. I did test fit an abs pipe into the holes just to see if they are a standard size, and a 2" pipe fits nicely which contributes to my desperate thought of how this all works. But, does this mean that that weird drain-looking thing on the wall of the shallow end is indeed another drain of some sort? If so, that seems to be a a weird place for a drain. Help me understand my drain(s), please. :cry:

The valve at the equipment seems to adjust flow between both skimmers at once and the suction port, but I am not 100% sure if that's only what it does. You see, I have had suction cleaners over the years that I used to hook to the suction port on the side of the pool when needed. Turning the valve seemed to enabled me to split suction, or whatever the proper term is, between the skimmers and the suction port. I could see the water level in the pump basket drop a little when I did this, but my cleaner worked, so I figured that's the way it works. I noticed last year, though, that turning that valve to enable flow from the suction port (remember, that's only how I THINK it works because I have no user's manual) caused the water in the pump basket to drop more than it previously did, as if more air is getting in that way (no, it's not a leaky hose). If I put my hand over the suction port itself, the suction still feels strong, but when I hooked up my cleaner it didn't seem to move as well as it used to. There are no valves in the vicinity of the suction port, so not knowing what else to do, I used the adapter that came with the cleaner to hook it to one of the skimmers instead. Any help would be appreciated here, too.

I'm not sure if I properly understand how any the plumbing and valves truly work here, and am trying to figure all this out so I can weigh my options to partially drain my pool. Can I somehow use the valves near the skimmers to stop flow to the skimmers and suck from the bottom drain using my filter pump, and just drain out the bottom of the filter housing? I ask this because before I got this cartridge filter, I had a DE filter. If I recall correctly, where the drain plug on my new-ish cartridge filter is, the DE filter had a spigot fitted onto the drain plug, or near it somewhere, and I wonder it that's why that was there. If I can indeed drain from there, maybe fitting a spigot into the drain plug would be a good idea ao I can regulate the drain rate?

Also, assuming I can somehow simply drain using my pool pump, can I just place my cleaner vaccuum hose down into the deep end, and use that for sucking up water?

Last question, is it safe for the plaster at the top of the pool to dry out during the time it takes to drain and refill, which I would think might be a whole day?

Thanks so much in advance for any thoughts, or suggestions.
 
Last edited:

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
15,073
Bedford, TX
foot,

As often is the case, a picture is worth a few thousand words... Show us some pics of your equipment pad and any additional Jandy valve that you might have.. Once we see the pics we will be able to give you some better answers..

The best way to drain a pool is with a sump pump and not your pool pump. You can rent one at Home Depot or buy your own.

Thanks,

Jim R.
 

MrLeadFoot

Well-known member
Sep 2, 2019
55
Sacramento, CA
Hey, Jim

Thanks for the reply. I wanted to get pics today bit it suddenly started pouring here, and for quite a while, too. I will try to get them tomorrow. In the meantime, why do you say to not use the pool pump? I mean, it runs for hours everyday anyway. Surely it's capable. Is there something I'm not thinking clearly about?

Thanks again
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
15,073
Bedford, TX
Foot,

You can use your pool pump to drain your pool, but it just makes is a little harder to do...

Once the water gets below the skimmers, your pump will start sucking air... This means you have to start using the main drain. No a big issue if your main drain is plumbed back to the equipment pad, as you can just turn a valve.. If your main drain is plumbed into the bottom of the skimmer, then you have to rely on a floating diverter valve.. sometimes they work and sometimes they don't... Depending on the pump, once the water gets below about half empty, then the pump has to suck harder to lift the water out of the pool. If there is any slight air leak in the suction line, the pump will lose prime. In most cases you will not be able to get the last foot or so out of the pool anyway, unless you use a sump pump.

I was thinking you wanted to drain your entire pool for some type of maintenance.. I re-read your post and if all you want to do is drain some of the water to lower you CYA, then you can use your pool pump as long as you can get your connection to the main drain to work..

The pics I requested were to help us decide how you main drain was plumbed into the system.

Thanks,

Jim R.
 

MrLeadFoot

Well-known member
Sep 2, 2019
55
Sacramento, CA
Got a little injury working on daughter's car, so took a bit for me to get these pics. Sorry for the delay.

Pic 1 is equipment pad.
Pic 2 shows plug at bottom of cartridge filter.
Pic 3 is of one of the valves just opposite a skimmer on the outside of aggregate "decking". There is another valve just like it near other skimmer.
Pic 4 is of the two holes under basket in a skimmer. As I mentioned one hole has suction the other doesn't.

Thanks again.
 

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