Skimmer Leak - (Pentair / Admiral S-10 w/no equalizer and floating basket with straight sides)

This one's been driving me crazy... I am close to finishing I believe.

-- URGENT need now --- Detailed installation schematic for "ADMIRAL S-10 PENTAIR" skimmer. The pool was built in the year 2000. This does NOT have an equalizer, and only has a single pipe that exits to bottom. HOWEVER, There appears to be a PLATE at the bottom, just above the pipe entry. I can put my fingernail under the edges of that plate, and the cylinder evidently sets on top or that plate. IT IS LEAKING DOWN TO THAT PLATE, BUT NOT BELOW THAT PLATE!!

I Need to ensure that I can SEAL around that plate, because I suspect this will fix the problem. But, I haven't been able to find a detailed manual to see how that is built. There isn't any check valve in this model, and there certainly is only ONE pipe leaving it.

  • 10,000 gal pool, central Florida, losing about 1/8 - 1/4 inch per day
  • Skimmer is tied directly and only to the cleaner line
  • Leak STOPS at the skimmer entrance, ie., it doesn't fall below that point (except for evaporation)
  • PLUGGED up the bottom of the skimmer, since water level is just slightly below skimmer and is therefore NOT getting anymore water from the body of the pool itself.
  • Used bucket to refill skimmer to pool level. Water leaked from skimmer within an hour, DOWN TO the 9" flat part, just above the return pipe. NOTE that the level did NOT drop below this to the plug I have embedded in the pipe inlet. (I reconfirmed there was no leak BELOW this 9" diameter floor, near where the pipe inlet is.)
  • Note to OTHERS that are using the "stopper method" to test. ---> When the 24 x 7 variable speed pump turns off for a few seconds as the schedule changes, that tends to KICK the stopper out, as the inlet pipe gets a short pulse of positive back-pressure from the pump's water level, and then resumes on high speed for the first 5 minutes.

When fixing the leak, I saw another post that had a suggestion and link :
"Get it dry and use PC11". I also have used silicon rubber for pool light leaks, (which really does cure eventually under water). Since this leak is stop intrusion from a NEGATIVE pressure however, it won't work as well to seal, when it has heavy suction applied.

SYMPTOMS: Losing prime / air in line when sucking only thru the skimmer / cleaner line. Once I think I got SAND sucked in strainer basket?. I'm concluding however, this still could have come from around the skimmer. But, I may/should redo the test with the stoppers in both the skimmer line and the cleaner line.

I NEED a detailed schematic / installation guide for THIS skimmer. I know there are threads on the bottom of the skimmer to the one feed line, but they appear to have good sealant. At the bottom of the skimmer, in the FLAT 9" section at the edge, I can put my fingernail under the edge... THAT DOES NOT seem right!! Maybe there was sealant or not enough?? Thus, I need the schematic to see how this was assembled. I can't tell what lies beyond this lip that is 9" in diameter. I HAVE confirmed that with the plug in the pipe, that the water leaks down to this level -- no more and no less. So it seems this is where it is leaking.
Since there is sealant that appears to have been used in the upper square part of the skimmer, at the bottom edge of the square inlet that joins the top and side, this sealant appears to be an integral installation component. If missing from that bottom portion, this might be an easy fix.

Before I conclude I've solved it, I will REDO the double stopper / lost prime / air / sand test above. But, I'm pretty sure that IT IS NOT IN THE PIPE. If the leak WAS in the line, then it would have continued to leak BELOW the square inlet to the skimmer, which it is not leaking below that.

QQ ?? I had recently blocked all other inlets other than the skimmer, and used a hose covering most of the skimmer's top 12", giving me max suction. Could this have led to creating the leak in a weak joint?? Again, I need to see how it is assembled to see if the joint above might be where it is leaking.

FYI --- In other news, my tablet feeder will NOT provide enough chlorine when running at slow speed 24 x 7. I've bought taps to drill into the pre-filter pipe, and run a small line into the TOP of the Pentair feeder. It has a variable valve and a one way valve, in-line. Cost?? About $6. I will let you know how that works out. Variable speed motors are a MUST to save a fortune in running costs, (~$75 month?) but... your feeder will never work properly without this modification.
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Gold Supporter
LifeTime Supporter
TFP Guide
Jul 3, 2013
Fletcher, OK
skimmers are a one piece mold so NO sealant is ever used.. if there is/was sealant anywhere it is leaking from there... You will need to clean it (if sealant was used all will have to be removed) and seal it with this wonderful stuff.. :) It will hold under pressure, I sealed a pipe that has had 19 pounds of pressure put to it and has not leaked in 5 years....



TFP Expert
Bronze Supporter
In The Industry
Aug 10, 2017
Morris Cnty NJ
I'm kind of lost reading this. Post pics of what skimmer you have. Theu are all 1 piece abs or pvc. Only joint is the piping below. You would be surprised at how well skimmer scum can hide a hairline crack.
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