Return jets pumping algae into pool. What could be the issue?

[Jlandon11]

Thanks for taking the time to read my post. Didn’t know whether to put this in algae or this subsection.

17,500 gallon in ground pool, Hayward sand filter S244SV, Hayward single speed pump, and I have a slide valve assembly not multi port. Main drain sealed off and using kreepy Krawler/ skimmer to filter pool.

recent test results from Leslie’s ( I know I should order my own kit, just bought the house 2 months ago)

FC 15, TC 15, PH 7.2, alk 128, CH 449, CYA 131, TDS 3400. (I plan on draining the pool come winter)

Pool has been clear last 2 months, but I didn’t know I needed to keep my FC higher due to my high stabilizer, so I let it get too low and now got a huge algae bloom I’m trying to take care of. But this problem has been occurring even when pool was clear and clean.

My pump will be running in the morning with clear water coming from the return jets, but when it stops and I restart it, green will suddenly be shooting out, this even commonly happens after I backwash. It feels so defeating because here I have a clean pool and I activate and pump and it’s sending mess back into the pool.

somethings I’ve noticed: I have a water coming out of the backwash pipe when the pump starts up. It’s a splash at first but slowly comes to a drip and then stops. I checked all the O rings and none are cracked and I lubed them up, but still having the issue.
Not sure how old the sand in the filter is. A pool guy is coming by on Monday to do some revitalization process to the sand? Not sure the exact name of what he’s doing. Said I don’t need to empty the sand I can just clean it out.

so what could be causing this blast of green? Do I need to buy a new slide valve assembly? Start with replacing O rings? Empty the sand filter?

I just feel like it’s taking a longer time than usual to clear up the green pool and I’m wondering if there’s something with my system that is broken.
Thanks!

 

[Katodude]

Did you order the test kit? Until you get it pour 5ppm of liquid chlorine in every day, then post a full set of results.

 

[Texas Splash]

Welcome to TFP! For your algae issue, you need to use the SLAM Process. For that, you also need one of the recommended test kits like the TF-100. See Test Kits Compared, Don't let the pool guy add any magic potions like floc, clarifiers, or algaecide. They will not kill the algae and can make things harder on you. Chlorine via the SLAM Process is the best way. But with a CYA of over 100, you will need a much higher FC level as seen on the FC/CYA Levels. I would try to exchange some water for now along with getting your own test kit right away. The pool store testing is often flawed.

As for your filter slide valve, they make rebuild kits that should help you with that leak. It's annoying, but has nothing to do with the algae. For the sand, he may just be doing a deep clean with a garden hose to stir it up. Make sure to read our ABCs of Pool Water Chemistry. Hope that helps.

 

[Jlandon11]

Did you order the test kit? Until you get it pour 5ppm of liquid chlorine in every day, then post a full set of results.

Yup, TF-100 is on its way. I brought another sample to a different pool store and they weren’t very helpful either but I’ve been keeping my FC above 10ppm and the green is going away slowly but surely. With my CYA of 150 I can’t afford the 86 gallons of 10% chlorine that pool math is asking me to get in order to get to slam levels.

 

[Jlandon11]

Welcome to TFP! For your algae issue, you need to use the SLAM Process. For that, you also need one of the recommended test kits like the TF-100. See Test Kits Compared, Don't let the pool guy add any magic potions like floc, clarifiers, or algaecide. They will not kill the algae and can make things harder on you. Chlorine via the SLAM Process is the best way. But with a CYA of over 100, you will need a much higher FC level as seen on the FC/CYA Levels. I would try to exchange some water for now along with getting your own test kit right away. The pool store testing is often flawed.

As for your filter slide valve, they make rebuild kits that should help you with that leak. It's annoying, but has nothing to do with the algae. For the sand, he may just be doing a deep clean with a garden hose to stir it up. Make sure to read our ABCs of Pool Water Chemistry. Hope that helps.

I think I will need a new slide valve assembly as whenever I turn the pump off I hear it sucking in air.

I read everything from pool school yesterday and wow am I blow away. I’m fully on board and bought my Tf-100 yesterday. However I’m in AZ where it’s 110 every day so I can’t drain my pool right now so I’m trying to figure out how I can maintain my FC high enough to work with my 150 CYA.

 

[Texas Splash]

I can’t drain my pool right now

Totally understand. There are some other ways to exchange water without dropping it first so you don't expose that plaster. You might check the link below for some ideas that may help. When you get your TF-100, do the "diluted" CYA test start at Step #8 as seen HERE.

Draining - Further Reading

www.troublefreepool.com

 

[Jlandon11]

Totally understand. There are some other ways to exchange water without dropping it first so you don't expose that plaster. You might check the link below for some ideas that may help. When you get your TF-100, do the "diluted" CYA test start at Step #8 as seen HERE.

Draining - Further Reading

www.troublefreepool.com

Thanks! I’ll get the results back to you when it arrives.

 

[Jlandon11]

Totally understand. There are some other ways to exchange water without dropping it first so you don't expose that plaster. You might check the link below for some ideas that may help. When you get your TF-100, do the "diluted" CYA test start at Step #8 as seen HERE.

Draining - Further Reading

www.troublefreepool.com

with a plaster pool, do you think the tarp method could work? Thinking through it, the tarp would cover the exposed plaster and not the water making direct impact so I’m not sure if there’s really any benefit to it?

 

[Texas Splash]

with a plaster pool, do you think the tarp method could work?

It might. @mknauss is one of our resident water exchange experts, so I'd like for him to chime-in on that one.

 

[Jlandon11]

It might. @mknauss is one of our resident water exchange experts, so I'd like for him to chime-in on that one.

Thanks!

marty I just read through your whole thread with VargusAz. I have a buddy who is going to lend me his pool pump. If I do the exchange method and pump the volume of my pool (17500), what should I expect in regards to change to my CYA?

how do I calculate the dilution and the affect exchanging the water will have? My CYA is 150, CH 450, TDS 3400. These are Leslie’s numbers as I am waiting on my tf-100 in the mail, But I have had it done multiple times and every time these measurements have been higher than recommended.

I can wait out the summer until November to fully drain it or just do the exchange or tarp method now. Not sure what’s best path forward. Thanks

 

[mknauss]

Read Draining - Further Reading

The efficiency of the exchange depends on the fill water vs pool water temperature, the Calcium Hardness (CH) of the pool water, and how patient you are.

Tarp method to me is dangerous. If you have any children or pets, I do not recommend it. You also need 10' or so of room around the pool without any obstructions. And a very large tarp.

Do you have active algae? If not, you can wait it out by running your FC at 10-15ppm. If you have active algae, you are kind of roped in to exchanging now. The exchange is based on removing and adding water at the same rate. Depending on the factors I stated above, you either pull water from the deep end and add in the shallow end, or vice versa. Read the article I have linked above.

 

[Jlandon11]

I do have algae and I am actively slamming. Read the article.

In regards to pump in deep end vs shallow, would a calcium hardness of 450 be deemed as high and be an indicator for putting pump in deep end? My hose water is not massively colder than the warm PHX pool water I have, but it is certainly colder.

 

[mknauss]

That is fairly low CH, your tap water has 250+ CH.

What is the temperature difference in the waters?

Your efficiency may not be great. But you really have little choice.

Once you get your test kit and know your real CYA level, you can then devise a plan.

 

[Jlandon11]

That is fairly low CH, your tap water has 250+ CH.

What is the temperature difference in the waters?

Your efficiency may not be great. But you really have little choice.

Once you get your test kit and know your real CYA level, you can then devise a plan.

Don’t have accurate temps. I’ll continue to fight the algae and wait for test kit for accurate readings.