Still have algae problems

[nonasdada]

hi. i read topic on algae treatment and prevention, but I have problems still

- situation: came back from 10 day holiday to a green oasis, pool about 22000 gallons
- chemical reading were FC 0, PH >8.2, TA 110, CYA 70
- brought PH to 7.5 and FC to 3 ppm
- used one quart of silver algaecide as per directions including brushing, backwashing, etc...
- then in evening shocked pool with 3 lbs of sodium dichloro s triaz.... Dihydrate (could not use the bleach calculator, cannot download on ipad so I used Calculator at http://www.swimuniversity.com/tools-dow ... calculator
- this morning, pool is transparent again but, still have greenish-yellow stains at bottom, I brushed all over, vaccuumed and backwashed and added water
- worried because now readings are FC 17.5 (yuk), CC 0.5, PH 7.3, TA 100, CYA 55

So, questions:
-how do I get rid or remaining stains, does that mean I still have algae,
- is FC way too high and how do I correct
- what is FC measurement for shock value

The pool was re-plastered at beginning of summer so I am not too keen on using metal brushes

Thanks for your advice

callyann

 

[jblizzle]

What did you do to prepare your pool for being gone for 10 days? Not too surprising that is was green when you got back.

Sounds like you need to go back and review Pool School.

You need to follow the shock process as described there. YOur FC of 17.5 is not even high enough yet ... shock level is up around 22ppm according to the Chorine/CYA chart.

You need to keep the FC up at shock level. Brush (with any brush) and be running the pump 24/7 until you pass the 3 tests to stop.

Stop using di-chlor ... it is adding CYA and fast.
Stop using algaecide ... it does not get rid of algae, wastes money, and sounds like if may be adding metal to your water which is never good.
Use the poolcalculator.com ... use a computer if it wont work on the Ipad (although I know many people use the app on Ipads ... so not sure why you have a problem).

If the pool was recently plastered, you should be paying more attention to your pH ... and you did not report your CH levels.

 

[nonasdada]

Thanks Jason

preparation, thorough clean up, chemical balance, raise water level. i wanted to get a cleaning service once but I was voted down. lesson learned.

Anyway. Ch is 280. PH all summer was between 7.2 and 7.5 graduations. Now is 7.3 As colour is closer to 7.2.

One more question - shall I remove the pucks I have in the pool right now?

I can use the pool calculator on ipad, it is the bleachcalc mentioned in the article I cannot download. Will use pool calculator.

And just to make sure, the 3 steps you mention is shock, brush and backwash until the FC reading is constant between sunset and early morning? Sorry sometimes still have problems with English.

Thanks

 

[jblizzle]

Often people raise the FC to shock level and then cover the pool when on vacations ... sometimes helps.

Your CYA is already on the high side ... and we do not know if the dichlor you added is in that total.
3 lbs of dichlor would have raised your FC by 9.1ppm and the CYA by 8.2ppm. And the pucks are adding MORE CYA ... so yes STOP using them ... only liquid chlorine from now on.

I do not know what bleachcalc does, so I would not worry about it. It may just compare the costs of different strengths and volumes of liquid chlorine, I think.

Review these:
Defeating Algae
Turning Your Green Swamp Back into a Sparkling Oasis
Shocking Your Pool

I did not mention 3 steps ... I was referring to the 3 tests to know when the shock process is complete (see the article above).

BTW, you should be backwashing your filter when the pressure goes up by 20-25% of the clean pressure.

 

[nonasdada]

Ok. Great

Good suggestion about raising the FC to shock level before departure, I did not think of that.First year for maintaining the pool, hopefully next year will be better

So, will remove the pucks and do the tests as you suggest

Thanks alot

callyann

 

[phipsi1237]

How did the cya drop from 70 to 55 after "shocking" with Dichlor?

 

[jblizzle]

How did the cya drop from 70 to 55 after "shocking" with Dichlor?

Good catch ... I did not even see the CYA of 70ppm reading.

Am I correct in assuming that the test results are from a pool store? CYA seems to be one of the test they are the worst at performing.

There is absolutely no way your CYA dropped after adding dichlor.

You really need a good test kit to verify the numbers before you even start the shock process. And there is no way to know you pass the 3 tests to stop without the FAS-DPD chlorine test.

 

[nonasdada]

hi

i do have a TF100 test kit so I am quite confident about the results of the testing. One of the articles says "...Murky water will cause the standard turbidity test (fill till the black dot disappears) to read higher than what is actually there... " so this might be the reason why there is a CYA difference.

last night (shortly after dark) FC was 25.5 and this morning it is 25 - there was .5 CC last night and none this morning.

So are those two of the tests? i have just reread some articles, not sure what the third test is? Sorry can someone tell me exactly what the three tests are. i read and reread the articles related to algae but am not sure

The water is clear, but now I do have stains at the bottom of the pool. After reading the article on metal and stains, it looks like I have to do a Vitamin C test or possibly use sequestrants to remove the stains. Is this what you would advise at this time.

Thanks

Callyann

 

[Smykowski]

The three criteria are...

OCLT 1.0 ppm or less
CC less than 1.0ppm
Water is crystal clear

Sent from my Exhibit II using Tapatalk.

 

[dmanb2b]

The water is clear, but now I do have stains at the bottom of the pool. After reading the article on metal and stains, it looks like I have to do a Vitamin C test or possibly use sequestrants to remove the stains. Is this what you would advise at this time.

Thanks

Callyann

Yes

 

[nonasdada]

Thanks everyone