Introduction and Solving Leak Issue

[wett]

I am a new pool owner, and as so many others before have said, this is an invaluable resource to people like me, and I can't thank you all enough for making this information available. I've been lurking for a few days and just reading reading reading, and it's been wonderful. I already feel so much more in control of my pool, despite the issues I'll address below. So thanks!

First, I should say that my pool appears to have not really been well taken care of by the former owner. I think it may have been at one time, but the house was a rental for the last few years and things clearly had gone downhill. When we went to open the pool a couple weeks ago it was a hot mess - several dead frogs in various states of decomposition, hundreds of tadpoles and frankly it just looked like a big pit of dirty toilet water.

Not knowing the first thing about pools we called the pool guy the former owner had recommended. He came and charged us a few hundred bucks to assemble the filter and throw a bunch of shock powder in the pool. He couldn't even catch the sole remaining bullfrog. I had to do that. He had serviced the pool over the last few years, so you'd think he would have been forthcoming about some important information, such as how he closed it last year with a layer of leaves and debris still on the bottom. Or, how the long flex PVC from the skimmer to the pump ran exposed behind the pool house and had several dozen holes in it, causing us to waste days worth of water trying to keep the pool full.

Anyway, since I took over maintenance and started reading here, I've replaced about half the suction side plumbing with rigid PVC to eliminate the visible leaks. I see there seems to be an ongoing debate on rigid vs. flex, but no more flex for me as I've seen first hand how it can wear. So far the new plumbing is holding up well and there are no signs of leaks. Unfortunately, there are another 20 ft. or so of flex PVC running under a concrete slab to the skimmer alongside the pool. The symptoms I'm having that lead me to believe the suction side leak remains are as follows:

a) significant air coming out the return
b) significant air in the pump basket
c) decreasing pool water level (fairly substantial at 1/4 to 3/8" per day)
d) significant sediment/sand settling on the pool floor that I can't seem to remove - increasing daily
e) small pebbles at the bottom of the pump basket

The remaining flex hose is laid in sandy/rocky soil below the concrete slab and I suspect a significant leak that is drawing in the surrounding earth/pebbles which are ending up in the pool and pump basket. It took me a few days to figure this out as I thought I had resolved the leak issue by replacing the flex hose that was accessible (not under concrete).

Anyway, I guess my question is has anyone seen these symptoms before, and can it be confirmed that this is the likeliest scenario for sand/pebbles ending up in the pool/pump basket?

Finally, thanks to pool school I did the overnight test last night/this morning and found a .5ppm loss of FC overnight but a CC level of about .6ppm. I used the 25ml test for greater accuracy because the 10ml test was giving me .5 CC and 3 FC, but the 10ml was giving .6 and 2.5. Should I still shock at .6ppm CC, or am I done? Water is crystal.

My full test numbers are:

CYA - 25-28 (Low, I know, but the pool guy put tabs in the chlorinator, so I expect this number to rise still - and I wanted to proceed cautiously with the CYA)
FC - 3 (added some CL this morning after the overnight test to bump this up a bit)
CC - .6 or .5 depending on 10ml vs. 25ml test
TA - 70
pH - 7.3
CH - 30
Water - crystal clear, extremely faint CL smell

Apologies for the long post and thanks again to everyone for such a great resource.

 

[Casey]

Welcome to TFP. Sound like you have a real gem on your hands and the only thing you need to do is polish it up with a lot of elbow grease.

Sounds like you still have a pretty significant leak. I'm not a pro on these but if the flex hose isn't run through the concrete but under it, you may be able to dig under the decking and support it so it doesn't collapse and then backfill. If it's run through the decking, well... you know you're going to need a jack hammer.

As far as CC's are concerned, anything under 1CC needs not SLAM'ed out of the pool. If you're passing the Overnight FC Loss Test then just maintain your FC according to your CYA. You will notice a slight fluctuation with the CC. Mine does it all the time.

Also, if you could add your City and State in your profile, we can get more specific with our answer to your location and help you a lot more than knowing you're in the North East. I'm in the North East too but I could be a 1,000 miles away from you. What we need to know to answer your questions

 

[wett]

Hi Casey,

Thanks for your reply. I've been busy. I ended up using a sledge hammer to deal with the 15ft. section of flex pipe that ran a couple feet below the concrete deck. The flex hose itself was somewhat deteriorated with evidence of some leaking. I couldn't tell for sure but I believe there may be some tree root infiltration. The bottom of the skimmer had another substantial leak and the connector was not tight at all. I wonder if this may have been the source of sediment into the pool?

After leaving everything dug up and exposed to the sun for a few days to see if any evidence of leakage remained, it appears there may be a leak still around the skimmer faceplate. It's a model 1096 by Hayward, which is an economy series skimmer designed for concrete/gunite pools. My pool appears to be fiberglass with a vinyl liner? I thought vinyl pools had metal walls, but the area around the skimmer is clearly fiberglass, at least from what I can see from excavating around/below the skimmer. Is this fiberglass/vinyl arrangement common? (Caveat, I know nothing about pools other than what I've read here in the last few weeks). Anyway, the problem with this skimmer is that it is designed for concrete pools and does not appear to come with gaskets. Sure enough I don't see any evidence of gaskets being used on this skimmer in my pool. The faceplate also has a couple cracks and a few of the screws appear rusty. The reason I think there is a leak at the skimmer faceplate is that the earth below the skimmer is still damp compared to the surrounding earth that has dried in the sun. Granted it's not getting direct sunlight, but there still seems to be some evidence of moisture coming from somewhere.

Short of replacing the skimmer (I'd actually like to use the pool this summer - maybe replace the skimmer after closing?) Can I add compatible gaskets (Hayward 1097 appears to be same size)? Or is there a clearance issue if this skimmer is not designed to be used with gaskets? The leaking itself has visibly slowed since plugging the skimmer bottom and removing the worn flex hose, but there is still a loss of 1/8" + a day, which appears to be slightly more than what's evaporating out of the bucket.

With the filter not running all this time I've just been adding chlorine to keep FC maintained and netting leaves/debris. Thanks again for any and all guidance.

 

[DogsHouse_MyPool]

Did the bubbles go away in the skimmer basket?

FC-3 is on the low side for a CYA ~30 pool. That will leave you susceptible to an algae bloom as FC will burn off during the day. I would work my CYA up to 40 and keep FC around 5 with daily maintenance.

The CL smell is along with the CC >0 is confirmation that the chlorine is oxidizing organic material. Keep the FC up and ahead of an algae bloom.

 

[Casey]

DogHouse, He's not running a filter and pump right now and I wouldn't recommend he add more CYA just because he isn't moving water atm.

Can you post pics of the skimmer, the walls and liner and the hole you've dug wett? I think it could give us all a better understanding of what you're dealing with.

 

[wett]

Sure thing. I'll try to get some pics up ASAP. Thanks guys!

 

[wett]

I took some photos but was unable to get them onto the computer.

Anyway, I ended up replacing the skimmer faceplate and added the 2 cork gaskets. There were 2 original gaskets, but they were a black paper material and totally waterlogged and deficient. The faceplate had many cracks on the back that were not visible from the front. I was able to remove to old faceplate and clean off the old gaskets fairly easily. The new cork gaskets and faceplate fit perfectly. I used some silicone on the screws.

The water level is about 1 inch below the skimmer, and it still appears to be dropping about 1/16-1/8th a day. I'm trying the bucket test but we've had rain so it's messed with the readings. What is an acceptable average rate of water loss due to evaporation? I've read that anything more than 1/4" a day indicates a leak, or that even 1/4" indicates a leak. At this point I'm ready to refill the pool to get the filter running before it turns into a swamp again. I've made all the suction side repairs, as well as the skimmer facelift, so I'm ready to see if it all holds together I guess.

Any thoughts?

BTW, it should probably be mentioned that my pool faces an open sky in direct full sun for at least 12 hours a day.

Thanks!