frighting green aglae CC 5.2, TC 0

[sethz]

Greetings, I am new pool owner. Long story short, the pool was neglected by previous owner last fall, they do hire people to close the pool, but my guess is they didn't vacuum it nor check chemistry.

For some reason, I just opened the pool 3 days ago (yeah, not too much time left, hehe), the water is green and muddy, bottom is covered by leaves. The opening guys throw a bottle of algaecide and two bags of shocks. Then I keep the filter running, and vacuum/brush, and backwash/add DE, again and again.

Today the pool looks much better, still little greenish though. I went to pool shop for water test, here it is:
FC 0
CC 5.2
pH 7.2
TA 70
CH 130
CYA 0

I have read through the pool school last 2 days. If I understand correctly, CC are the dead soldiers fought algae or other organic. FC 0 mean I don't have any live soldier available. So I am losing the battle against algae, right? I poured 5 lb cal-hypo 65% 4:00PM today, according to poolcalculator, it will raise FC to 20 for a shock. (next time I will try household bleach).

Also there is no cyanuric acid at all in the pool. So I plan to put 5lb stabilizer tomorrow (according to poolcalculator, it will raise CYA to 30).

I am a total newbie. All my knowledge came from reading pool school and Tamminen's book last 48 hours. Please feel free to advice/comment. Thank you

 

[dravenone]

You need to check your FC several times a day and add bleach to keep the shock level (just the higher FC level) constant. Also get as much organics out of the pool as you can, leaves, branches, anything you can scoop with a net and get out, do it. Pool school will tell you what shock level to shoot for based on your CYA. Also CYA can take a week to register on a test, so give it some time after you added it.

 

[chem geek]

Did the pool have CYA in it when you closed it? If so, then bacteria may have converted the CYA into ammonia in which case you may need to add a lot of chlorine. With a good test kit that doesn't bleach out at high chlorine levels, you can keep adding chlorine every half-hour or so until it starts to hold. Or you can do a bucket test to see how much chlorine it will take before it starts to register -- 1/4 teaspoon of 6% bleach in 2 gallons is 10 ppm FC.

Soon after you start to hold chlorine in your pool, then you can add a small amount of CYA to protect it from sunlight (even 10-20 ppm would be OK to start out). I wouldn't wait until the pool is clear before adding CYA -- too much will get broken down by sunlight during the day -- but right now when you aren't getting a chlorine reading just use chlorinating liquid or 6% unscented bleach and wait on the CYA until later on when the chlorine registers shortly after adding it. Adding 10 ppm FC at a time (the shock level with no CYA) is reasonable until it starts to register. When you start getting a chlorine reading then if you wanted to add CYA and add chlorine at the same time to clear the algae, you could use some Dichlor powder, but don't get too much since you'll only want to add around 30 ppm FC cumulatively (10 ppm at a time) since that will give you roughly that amount of CYA (a little less). Adding pure CYA as was suggested above is another option but as was noted it will take time to dissolve.

Remember that chlorine is a consumable so you need to keep adding it if it gets used up quickly -- but you also need a proper test kit to ensure you aren't bleaching out the chlorine test. If you can't get the Taylor K-2006 quickly, then at least get a cheap OTO (shades of yellow) chlorine test that will at least tell you if you've got chlorine in the pool, but get a proper test kit as soon as you can -- it's at a good online price here or you can get the TF100 from tftestkits.net here with the latter kit having 36% more volume of reagents so is less expensive per test.

 

[sethz]

Thank you, dravenone and chem geek. I will keep your advices in mind for the comming days adventure.

A follow up, this morning the pool water LOOKs crystal clear. I bring the water sample to the pool shop again:
FC 0
CC 0
pH 6.9
TA 50
CH 225
CYA 0
Phosphorus 200

So even I putted 5 lb cal-hypo 65% yesterday 4pm, now all chlorine is gone .
This time I pour 368 Oz bleach, 4lb borax, 4lb baking soda at 4pm. (will do a bucket test after the post)

I went to local Leslie's, they don't even stock the rebranded Taylor K-2006 kit that everybody recommended. Will order online.

BTW, pool shop guy mentioned the 200 ppm Phosphorus is high, and that's why pool won't hold chloride (I doubt this). He recommended expensive phos-X, I recalled pool school's comment about phosphorus, I said I will pass.

 

[JohnT]

You need to check your FC several times a day and add bleach to keep the shock level (just the higher FC level) constant.

This is the important part.

If you don't keep the chlorine up, it will never clear. Even letting it drop to 0 overnight sets you back to the beginning of the process.

 

[sethz]

To report back, my Taylor K-2006 kit arrived today.
FC 1
CC 0
pH 7.6
TA 90
CH 150
CYA not tested (added last weekend, expected 25~30)

The water looks clear, I guess now it's back to normal maintenance status. Thank you all for the help.

btw, I also tested my tap water (from private well):
FC 0
CC 0
pH 6.9
TA 10
CH 30

 

[frustratedpoolmom]

The water may look clear, but your FC is too low. You don't want it lower than 2. Tonight, add enough to reach 4ppm and then do an overnight loss test. Instructions for that are in Pool School. If you lose more than 1ppm overnight, you are not done shocking the pool.

 

[sethz]

The water may look clear, but your FC is too low. You don't want it lower than 2. Tonight, add enough to reach 4ppm and then do an overnight loss test. Instructions for that are in Pool School. If you lose more than 1ppm overnight, you are not done shocking the pool.

You are right. after my post, I always keep FC level 3~4 ppm.

I just did an overnight test, lose 0.6 ppm at night.