Just bought a house with a pool, do I need to SLAM?

[perfectionsoup]

I am in the process of purchasing a house with an inground fiberglass pool, built in 1981, approx 25,000 gallons, located in Albuquerque, New Mexico (full sun all day). It has a gigantic sand filter that is as old as the pool itself, not sure of the pump brand/hp just yet. The who owns it right now uses the chlorine pucks in the skimmer basket so I'm sure the CYA is sky high and I will need to do a partial drain once I take over. Otherwise he just takes water to the pool store and does whatever they tell him to do, but he tells me the numbers are all decent. He does leave a solar cover on it all the time to heat the water, which might be contributing to the cloudiness. I will have a T-100 test kit here by the time I take over the pool. Right now, the water looks okay, is a nice bright blue, but it's a little hazy/cloudy. I'm wondering if that will clear up with proper attention and testing and leaving the cover off some, or if that's something that will really only go away with a SLAM. My main priority is to be able to swim ASAP, can you still swim in the pool while doing a SLAM?

Pics of the current water condition, picture with the stairs was taken in the shallow end.

 

[jblizzle]

Welcome to TFP!!!

First step will be to test everything ... that determines the path forward (i.e. replace water first or not).
I would want to clean the filter (Deep Cleaning your Sand Filter) and go through the ShockLevelAndMAINTAIN Process just to be sure I was starting off on the right foot.

It is safe to swim in a pool full of algae (assuming you can see the bottom) as long as there is FC in the pool above the minimum for your CYA level ... see the FC/CYA Chart. We recommend not swimming if the FC is above shock level though.

 

[ellsian]

Wow! A 33 year old fiberglass pool, impressive! I thought they started cracking after 15-20yrs. I can't help you out on the chemistry, sorry. Just amazed to see fiberglass that old and still doing well. I was considering getting a fiberglass pool myself but almost everyone here in AZ does shotcrete/gunite. Anyways, apologies for the tangent, congrats on the new house/pool and good luck fixing the water!

 

[perfectionsoup]

Okay, will plan on doing a SLAM to get it started off right. Obviously will need to test first in case I need to drain some! I'm just excited to get in there and start swimming, didn't want to have to do a SLAM if not necessary. I guess it will be a short and sweet SLAM if there's nothing in the water anyway right?

As for the age of the fiberglass.....yeah, it's ancient! It has hairline cracks on the coping around the pool edge that my pool inspector assured me are purely cosmetic, and otherwise it's in great shape, so hopefully it will continue to last! Arizona's climate should be pretty similar to New Mexico, just even hotter so I would imagine a well maintained fiberglass could last forever there too.

 

[perfectionsoup]

Okay, I officially own this house now, here are my numbers:

FC 7
CC 0.5
pH 6.8
TA 20
CYA 50

I added 76 ounces of borax to raise the pH (pool math said 73 but I did the whole box of 76 for simplicity). I also pulled 3.5 pucks out of the skimmer to stop adding any more CYA. Will be over there in the morning again and will recheck FC and pH. The pool water at this time actually looks better than before, not cloudy at all. I don't have any more pictures unfortunately. I think I'll toss a quarter in tomorrow and see how it looks in the deep end (9 feet).

So, questions:

Since my CC is 0.5 and my water is clear, no need to SLAM, right?

How soon after adding borax can I check the pH again? Also, aeration raises pH yes?

I know I need to check FC everyday at least until I get used to the pool, is there anything else I should check daily? Is once a week enough for pH once I get it in range?

I need to get a picture of my ancient sand filter to post here, as I am unsure how to open it to deep clean it. It doesn't seem to have any kind of a hatch or door for easy access. I will grab a pic tomorrow, and also a pic of the water quality.

 

[joegus]

Nice looking pool, welcome to TFP! The water looks pretty good! Good deal to remove the pucks to prevent the CYA getting higher but in your climate and full sun exposure, the 50 CYA won't hurt. You can check your PH about 30 minutes after adding if you are leaving your pump on, and yes, aeration to raise it will work if needed. If your numbers are correct, I would see no reason to SLAM, but I might suggest you get your TA up. I would shoot for a TA of 90 and go from there. That will raise your PH also, so I hope you didn't over do it. Your sand filter will greatly benefit with a cleaning or sand replacement.
As far as testing, you will get a feel for your pool as you go along. I test just about every day for FC and PH. If I'm in a hurry and I know I've been adding the same amount of bleach every day I will just add what I have been. (Don't do this too many days because conditions change fast) Once you get your CYA to stabilize, the only time I test for it is if I have to add a lot of water (splashout, evaporation etc...) get a lot of rain or at least once a month. TA, CC and other tests I try to do at least every two weeks or twice a month. Again, you will get a feel for your own pool and conditions. Good luck!

 

[pwrstrk]

Okay, I officially own this house now, here are my numbers:

FC 7
CC 0.5
pH 6.8
TA 20
CYA 50

I added 76 ounces of borax to raise the pH (pool math said 73 but I did the whole box of 76 for simplicity). I also pulled 3.5 pucks out of the skimmer to stop adding any more CYA. Will be over there in the morning again and will recheck FC and pH. The pool water at this time actually looks better than before, not cloudy at all. I don't have any more pictures unfortunately. I think I'll toss a quarter in tomorrow and see how it looks in the deep end (9 feet).

So, questions:

Since my CC is 0.5 and my water is clear, no need to SLAM, right?

How soon after adding borax can I check the pH again? Also, aeration raises pH yes?

I know I need to check FC everyday at least until I get used to the pool, is there anything else I should check daily? Is once a week enough for pH once I get it in range?

I need to get a picture of my ancient sand filter to post here, as I am unsure how to open it to deep clean it. It doesn't seem to have any kind of a hatch or door for easy access. I will grab a pic tomorrow, and also a pic of the water quality.

I don't see anything that suggests you need a SLAM.
30-60 minutes after the borax you can test. Did you dissolve the borax before the addition ? I would test PH everyday for a week to see how stable it is. If it rises up to 7.8 lower it with acid.
Your TA is a bit low. Use baking soda to get it up to 70.
I don't see a CH test. Low CH can cause damage to the gelcoat of the Fiberglas. Your CH should be 220-320.

 

[perfectionsoup]

I just poured the borax in very slowly over the return with the pump running. It appears to dissolve right away, I just didn't stick around to retest yet as I needed to go finish packing at my other house! Today is moving day so I will test as soon as I get over there and see how it looks now.

I haven't added anything for the TA yet as I was under the impression that raising the pH will also affect the TA and I was trying to fix one problem at a time. Would it have been better to attack the TA first and let that help the pH?

I also thought CH only mattered for plaster pools, which is why I didn't test it. I've been reading these forums and pool school for more than a month, but it's been info overload without a pool to actually fiddle with. So, I will check the CH this morning also.

Thanks for the replies!

 

[pwrstrk]

No you did the right thing with adjusting the PH first. The borax will raise the TA some. At the bottom of pool math, Effects Of Adding Chemicals, it will tell you how much X amount of borax will raise TA.
Good luck on your move ! ?

 

[perfectionsoup]

Okay, I added 56 oz of baking soda for the TA, new reading was 60. Just added another 56 oz baking soda now, will retest in about an hour. The pH came up to about 7.3 with the first baking soda addition (just slightly more red than 7.2)

I'm planning to recheck FC this evening and make that an evening routine along with adding bleach.

My robot cleaner is going to town right now, and I'm excited to hop in after a long day of moving!

Anything else I should be doing?

- - - Updated - - -

Forgot to mention, my CH was 350, so I think I'm good on that front!

 

[pwrstrk]

Looks like you got a grip on things. Good job ! ?