Plumbing questions on old pool

[Bal]

I need some assistance in confirming my suspicions. We bought a home with a 1972 pool. The pool needs new coping, surface refinishing etc but we are not ready to do that work financially yet. In the mean time, I have replaced the motor with a 2 speed and installed a timer to cut back from the 24/7 high speed operation to low speed 12 hours a day (two 6 hr periods).

I noticed prior to the install when the skimmers got full the pump seemed to be starving, with the return jets pushing out very little water and bubbles. I thought the bottom drain would keep that from happening. Does this mean the bottom drain may be plugged?

Also, is it normal a pool of this age would have only a single suction line? (see the pic in the thread below). I figured there would at least be a bottom drain / skimmer line T above ground even if it didn't have a valve. But my pump station only has one suction line and one discharge.

I ask because we pay a cleaner now and as I move to doing this myself I wanted to get a kreepy Krauly or equivalent but without suction control I am not sure how it will work.

Please refer to this thread for pics of the pump station and pool information
http://www.troublefreepool.com/updated-new-timer-and-pump-roi-t63418.html

 

[JohnT]

Often pools are plumbed such that there is only a single line from the skimmer to the pump even with a main drain. You can generally identify this type of installation by the fact that you have two open holes in the bottom of the skimmer. The hole closer to the pool is plumbed to the drain, and skimmer flow draws some water from the drain.

If your skimmer basket leaves as gap underneath, you should still be able to draw water from the drain when the basket is full.

 

[Bal]

I will check to make sure but that would make sense. Correct me if I am wrong, but when the baskets get full the pump still receives some water from the bottom drain lines to the skimmers but the suction draws more than the head pressure forcing flow to the skimmer from the bottom drain lines can keep up with. Hence I get air/water mix from the skimmers when the baskets are full.

Ok, but to my goal, a suction side cleaner should work fine in that scenario correct? Are there any recommended models?

Thanks for the help!

 

[JohnT]

Ok, but to my goal, a suction side cleaner should work fine in that scenario correct? Are there any recommended models?

The problem with using a suction side cleaner with your setup is that the cleaner becomes the primary source of water for the pump. That can induce excess restriction that causes the pump to lose prime. Predicting whether that will happen to you is hard. You can get a diverter to allow some flow from the drain while the cleaner is hooked up, but you just generally don't have as much flexibility as a setup with dedicated lines and valves to adjust suction.

 

[Bal]

Makes sense. I have two skimmers, so what can I use with the second skimmer to provide some control over suction while utilizing the first skimmer for a cleaner? Some type of valve installed into the suction in the skimmer?

Once again thanks for the help. The information on the main drain being piped back to the skimmers is a big insight. I did not realize they did that and did not think to look.

 

[JohnT]

Makes sense. I have two skimmers, so what can I use with the second skimmer to provide some control over suction while utilizing the first skimmer for a cleaner? Some type of valve installed into the suction in the skimmer?

Once again thanks for the help. The information on the main drain being piped back to the skimmers is a big insight. I did not realize they did that and did not think to look.

With two skimmers you probably can deal with it.