Can I save this pool without partial draining?

[VW_McKinney]

Hello All, I am new to the forum. I have quite a challenge and would appreciate your help.

Pool: 24,000gal non-swg gunite, pebble tec surface, in-ground pool with overspilling spa and waterfall. We live in the Dallas, TX area and it is hot and sunny. Pool is used almost daily by three people.

The Story: Bought a new house with pool six weeks ago. I have quite a bit of experience with SWG pools. Wife convinced me that she could maintain the new pool better than our pool company. I get back in town yesterday after three weeks of travel and the pool is a mess - algae, zero chlorine readings, high TDS. Turns out my wife thought it was a SALT WATER POOL when it is NOT! So while she dutifully went to the pool store to get water analyzed and supplies she ended up adding a ton of salt (hello TDS) and never adding chlorine besides shock each week (hello zero FC, high CYA and algae).

Water Status Today: FC=0, CYA=80, pH= 7.8, TA=90, CH=325, TDS=4000 tested at Leslie's (I don't have a test kit yet)

Concerns: CYA is already high with no FC so I will need to add a lot of chlorine. Green and yellow algae present. High TDS complicates my already dicey chemistry.

Actions Taken Today: Fired wife as pool boy. Shocked with 3lbs of 73% Calcium Hypochlorite shock. Brushed pool. I have a good Polaris 3900 automatic pool cleaner. Leaving pool pump and cleaner on 24/7 until issues handled.

Questions: I have already calculated the necessary liquid chlorine needed on Pool Calculator and bought bleach to treat the pool so I can maintain FC without further raising CYA.
1. Should I drain at least 25% of my pool to lower CYA below 60 and TDS below 3000 or can I get this in shape just through chemistry and gradual dilution? It is over 100 degrees and we get quite a bit of evaporation but I don't want an algae battle that lasts for weeks.
2. Should I use Algaecide after shocking?
3. How often do I need to backwash my filter due to the algae?
4. What other actions do I need to take?

I have guests arriving next weekend and I want the pool to look great but then I also don't want to dump and refill 6,000 to 8,000 gallons of water if I don't have to. Thanks for your help, VW

 

[jblizzle]

Welcome to TFP!!!

TDS is meaningless and we do not care about it. You need to invest in one of the Recommended Test Kits before you are going to be able to make much progress.

That CYA is not ridiculously high and you should be able to clean it up without having to replace water by following the ShockLevelAndMAINTAIN Process.

Cal-hypo is not a good idea as that is just going to make your CH rise faster than it will just due to evaporation ... eventually leading to needed to replace water.

1. It would be a little easier to SLAM if you replaced water to lower the CYA first. Again, TDS does not matter (it is just a sum of CH, CYA, salt, etc which we prefer to see separately)
2. NO. All you ever need is chlorine.
3. We recommend backwashing when the pressure rises 20-25% over the clean pressure.
4. Order a test kit ASAP!!! The SLAM process takes time and I am not sure you will have it done by next weekend. The pool did not go to green in a few days so don't expect it to clean up in a few days.

 

[poolnoob.ca]

Hi VW, others are probably typing as i am, and they are probably saying TDS is meaning less here at TFP, and yes we can help you recover your pool. But instead of firing your wife, sit down together and click on "pool school" above, and you can learn together how to manage your pool inexpensively using chemistry and science. The salt wont do any harm, will make the water feel nicer if anything, and they dont use algaecide here at TFP. Best wishes and welcome

 

[epro05]

Shock level for CYA of 80 is 31ppm FC. It will take 10 jugs of 8.25% bleach to reach that and more jugs to SLAM. Read the SLAM article in Pool School. You have to keep the FC at, or a little above, 31ppm until you pass the criteria for a successful SLAM. Don't use the algaecide. You need to backwash the filter when it is about 20% to 25% above your normal clean filter pressure (pressure you see just after a backwash).

 

[VW_McKinney]

Thank you all for your advice. I have never used Algaecide before but my wife purchased some hence the question. I realize that if my FC is good, then there is no need for other algae treatment. I have already ordered a test kit. I have never worried about TDS but then I have never added salt to a non-SWG pool either so it is good to know that wont be a problem.

I have covered some of the Pool School info (which is why I bought liquid chlorine and have not used the large bucket of tri-chlor tabs my wife purchased). Is there a secondary market for unnecessary pool chemicals? Lol, I have come home to a veritable pool supply store (tabs, algaecide, shock) when all I really needed was bleach...

 

[kimkats]

Most of it you can take back and get more money for bleach LOL.

Kim

 

[VW_McKinney]

Re: Can I save this pool without partial draining? A little more help please...

Got my Taylor K-2006 test kit as well as an OTO test kit supplement yesterday morning. Turns out the pool store's CYA measurements were way low. My CYA is well over 100 (I estimate 120-130 range) and my Calcium Hardness is 400. No choice now but to drain. Rented a high volume submersible pump yesterday evening and drained 2/3 of the pool. Today I rinsed and brushed the steps, walls, shelf, hot tub areas that get the most algae growth with a diluted bleach solution (1 cup 8.25% bleach for every gallon of water) and then rinsed with clean water. Began refilling the pool.

Following the SLAM protocol, I continued to shock the pool Sunday and Monday. Visible algae is gone but I know I am not done yet. I want to continue to treat for algae to the best of my ability while the pool is refilling and there is no circulation (probably a two-day process). I am guessing that my final CYA is going to be around 40, so I am estimating my volume and shocking to an FC of 16. Does this seem reasonable?

Once my pool is full and recirculating, is the first step to reestablish the proper pH? Exactly what do I need to do before continuing my SLAM process?

 

[pabeader]

adjust pH 7.2
test CYA to get proper FC
SLAM!!

 

[Patrick_B]

Welcome VW, and kudos for the aggressive action!

Yes pH first, double check Cya, and start Slamming. Right now, you need to order refills for the FAS DPD Test. If you aren't out before you finish, you won't have much if any left afterward.

If you have 40 Cya, I suggest dosing for 18 up front because you'll be down to 16 in no time. Maintain is critical in the SLAM. The better you maintain your SLAM value, the faster this will go. Do your utmost to never let it fall below 16 FC.

 

[VW_McKinney]

Thanks everyone. I will let you know how it goes.

 

[VW_McKinney]

Re: Can I save this pool without partial draining? Almost done...

Ok, everything has gone really well. I kept my FC levels up while the pool refilled and all my chemistry is looking good. My SLAM is done: CC is 0, water is crystal clear, passed overnight FC loss test. Current readings at 9 am: CYA 35, FC 4.5, CC 0, TA 100, pH 7.6, CH 200.

The calcium hardness is my concern. I used Pool Calculator and it indicated that I needed 471 oz (29.4 lbs) of calcium chloride dihydrate to raise CH from 200 to 300 for my 24,000 gal pool. I have never had to adjust CH before but that seems like a lot. Do I add that all at once or over time?

 

[Texas Splash]

You're in really good shape. Based on the TFP recommended levels, your CH only needs to go-up about 50ppm, so I'd just go to that minimum per the Poolmath calculator . I suspect any refills will add CH quickly if your water is hard like mine. Just watch that FC in our heat. I actually keep my CYA at 60-ish with all of our sun to protect my FC. But you seem to be doing well. Enjoy!