In-ground swimming pool question

[retired53]

I bought this house with an in-ground swimming pool 2 years ago.

Never had any problems until now.

It's a pool spa combination. About 10,500 gallons. Two skimmers. Two drains (pool and spa) heater, floating chlorine dispenser, sand-filter and Polaris. Pool is about 35 years old.

Just recently it started getting air bubbles coming out of one of the spa input jets. I can hear some air going through the plumbing near the filter/multi valve. I don't see any bubbles going into the main pump filter basket.

The sand filter's pressure gauge indicates a small decrease in pressure (approx drop from 17lbs to 16lbs) but when any leaves get in the pump filter basket the pressure drops dramatically. (past 10 lbs)

I've also noticed more sand in the pool from the filter

Questions:

How can I track down the leak?

Could it be the valves gaskets?

Does a worn spider gasket on the multi valve cause sand in the pool and could this be where I'm getting the air bubbles from?

Could the air be coming from a pump gasket?

TIA

[Don Phillipson]

Seek pool store advice. No sand should reach the pool from the filter.

[retired53]

Yeah...I did a little research and it said I may need to drain the filter take out the sand and replace the laterals (not sure what those are) I'd contact my supply store but those kids usually aren't much help. I'd rather figure it out on my own. Cheaper, and *usually* gets done correctly. It's not rocket science. :^)

[John Keiser]

Changing the laterals - assuming you can find replacements - can be a lot of work. [Consider removing several hundred pounds of sand through a small opening.] Changing the the spider gasket is cheap and easy. Try that first. On the other hand, I get a small but detectable amount of sand after backwashing. Done this for years and never progressed to anything major. I'd keep an eye on the situation before making any major decisions.

[retired53]

I was doing more reading on laterals and it said to just replace the whole filter is much easier. Considering the filter is 35 years old I think I'll just let it ride for awhile. The sand amount is pretty small and it has been doing it since I got it.

I backwash a lot too. Maybe too much. I read, on the internet, that I should wait until it gets 10lbs over not 3 to 4 lbs like I was. I'll cut back on the backwashing.

It really sounds to me like the air is getting in through the pump gasket. I almost positive the spider gasket needs replacing too. I had some issues with it backwashing into the spa.

[Dan Espen]

Look for leaks on the intake side. Start at the skimmer. I've seen little whirlpools develop in the skimmer letting air into the system especially if the water level is low.

As others said, a little sand is no big deal.

The laterals are arms at the bottom of the sand filter that let water exit the sand. Wait til you want to change the sand before inspecting there.

[charlie]

shop vac with a thin hose

[olddog]

I keep the water level high enough to keep air from coming in through the skimmers. I can see the water flowing through the pump basket. It has one of those transparent lids. I don't see any air bubbles coming in there. I do hear some unusual noise near the pump. It's not coming from the multi valve or filter. It sounds like it's coming from the pump housing. I had the gasket replaced two years ago. So it makes me wonder why it went out so fast.

Anyway, I think I just need to go through it and replace all the gaskets before I tear apart the filter.

I wonder; Why is it so hard to replace the sand if it's susposed to be done every five years? I have no idea how long it's been since it's been replaced. How can I tell?

[olddog]

olddog = retired53 (different computer)

[Dan Espen]

It's not hard to replace the sand providing...

My filter holds 2 50lb bags of sand. That's 100lbs dry, a bit more damp.

I can still reach under the deck lift out the filter full of sand and pour the sand into a wheelbarrow. But I wouldn't call it easy.

So providing you're strong enough it's easy as pie.

[John Keiser]

Depends on the size and configuration of your filter. It is more tedious when you have 500 pounds of sand to remove through the top. The shop vac is essential but the job still takes awhile.

[olddog]

Mine would have to weigh in that range.

I'm still wondering: How can I tell if the sand needs changing.

Also, did you ever repair the laterals?

BTW: Thanks for the tip on the Shop Vac.

[John Keiser]

Weigh is proportionate to diameter. 36 inches is probably 500 pounds.

I've changed my sand once in 30+ years and even then the grains felt sharp. So probably not necessary. I'd guess you'd notice inefficient filtering eventutally but the "5 year" rules seems vastly over-rated.

After 30 years, my Tahitian developed a leaky valve. No parts available. If yours is of that vintage, I question availabliity of valve parts or laterals [these are just plastic tubes with slits that snap to screw into the main pipe.] I bought a used Hayward on Craigslist for $50 because parts are available. Changed the spider gasket and good to go. Replacement laterals available.

Good luck.

[retired53]

Mine's a Baker Hydro. Parts are still available.

Filtering is still excellent so I guess:"don't fix it if it ain't broken".

I've looked at some of the valve gaskets and they are in bad shape so that's what I'm going to do. I have two extra valves because of the spa.

Good idea to look on craigslist for replacement parts. I wouldn't have thought of it.

[Oren]

An auto store will carry gasket material; for making your own gasket.

I've not make a pool valve gasket, yet. The thread reminded me of the material and tools in the tool box. Draw and cut is easy...

Caution on used gaskets taken from parts. New is better, unless you make yourself one.

[olddog]

Good idea if the gaskets are not available anymore but the gaskets would have to be able to withstand chlorine. I doubt the spider gasket would be "easy"

I wasn't thinking of getting gaskets off of Craigslist. I was thinking of getting the entire filter.

Looks similar to this

[John Keiser]

You are somewhat in lucky then. Baker Hydro also makes a valve that can be made to fit my old Tahitian but it was very pricey and I'd still have had

30+ year old laterals which are not available. Baker Hydro did not have the actual gasket for the Tahitian, although I think they made the oringal valve. I've competently made "o" rings from stock [razor + crazy glue] but, as another poster mentioned, making a spider gasket is too complex.