water flow. skimmers, eyeballs, etc

[keithpgdrb]

recently opened the pool. got to thinking about things I'd like to improve, and what is really worth the effort or not.

1. found that the ring on the outside of one of my eyeball returns is cracked. in researching replacement pieces, I discovered that there are different, eyehole sizes. I havent measured mine yet, but I was thinking of getting a smaller eye hole size to increase the movement of the water. advantage? disadvantage?

2. I am experimenting with dropping my pump RPM. essentially the SWG stops working below 1500, so I have set it to about 1700 rmp. OK? I figure I may need to turn the SWG percentage up a little because of the decrease in flow? just to keep everything where it needs to be.

3. I noticed that one of the two skimmer baskets seems to have weaker suction or movement than the other. My pipes are currently set to have both skimmer baskets and the main drain to full open. I recently read in an old thread that you dont really need to have the main drain fully open? likely because of the pressure at the bottom of the pool. what is the ideal setting for a main and two skimmers? I am thinking of closing the main drain a bit, increasing the pull from the skimmers. thoughts?

 

[wireform]

Decreasing eye ball size will just push a bit more water to the other larger ones and is used when there are many returns to get better push to the farthest ones.
RPM needs to be adjusted to just before the point where the heater and the SWCG cut off then add 100-200 rpm and call it good. Not necessary to change SWCG % as it could care less of the pump speed and keep doing its job the same at any pump speed.
Skimmers do as their name implies which is to skim the waters surface therefore it's more important to give priority to them versus the main drain. Since you have a main drain you can limit it to 10% open and the rest of the suction is reserved for the skimmers. As you've stated you have separate valves for the skimmers so you can valve off a little of the stronger one and open more of the weaker one which is essentially balancing the two to make them equal.

 

[Jimrahbe]

Keith,

I was going to reply to your questions, but I can't think of anything I can add to what @wireform says his post above..

Thanks,

Jim R.

 

[mas985]

recently opened the pool. got to thinking about things I'd like to improve, and what is really worth the effort or not.

1. found that the ring on the outside of one of my eyeball returns is cracked. in researching replacement pieces, I discovered that there are different, eyehole sizes. I havent measured mine yet, but I was thinking of getting a smaller eye hole size to increase the movement of the water. advantage? disadvantage?

Reduced orifice increases the water exit velocity of the return but it also increases the head loss so to get back to the same flow rate, VS RPM may need to increase.

2. I am experimenting with dropping my pump RPM. essentially the SWG stops working below 1500, so I have set it to about 1700 rmp. OK? I figure I may need to turn the SWG percentage up a little because of the decrease in flow? just to keep everything where it needs to be.

Again, this is counter to #1 so you may need to increase RPM after replacing the eyeballs. Also, SWG percentage does not need to change with flow rate.

3. I noticed that one of the two skimmer baskets seems to have weaker suction or movement than the other. My pipes are currently set to have both skimmer baskets and the main drain to full open. I recently read in an old thread that you dont really need to have the main drain fully open? likely because of the pressure at the bottom of the pool. what is the ideal setting for a main and two skimmers? I am thinking of closing the main drain a bit, increasing the pull from the skimmers. thoughts?

My main drain is barely open. They really don't do very much and can be mostly closed off so that the skimmers get most of the flow to keep the surface clean. However, a little flow is good just to chlorinate the line.

You can make the skimmers have equal flow but that also means that you will be restricting (i.e. higher head loss) the flow in one of the skimmers in order to do that. I have two skimmers and one has more flow than the other and I just leave it that way. It doesn't seem to affect the skimmer with the lower flow rate all that much. However, you do want both skimmers to have water traveling over the weir door instead of around the sides so you may need to make some adjustments to achieve that at the lowest RPM possible.

 

[wireform]

However, you do want both skimmers to have water traveling over the weir door instead of around the sides

Please explain, ty

 

[mas985]

When setting the RPM of the pump, you want to make sure RPM is high enough so that water travels over the top weir door instead of through gaps on the sides. That way debris more easily travels into the skimmer instead of building up in front of the weir door blocking the skimmer.

 

[wireform]

Oh thanks, knew that but thought I can learn something new. Ty