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I have an 18X36 ~25000 gallon in-ground vinyl pool that has a mesh cover. I've only owned a pool for about 3 years now. Still learning.
My problem is every year I open the pool it has a massive algae.
I have two questions.
1) What is the best way to clear this up?
2) Is there anything I can do to help prevent this in the future?
Thanks for your help.
First thing is to get a good test kit. The only one we recommend is not available locally but if you will click on the test kit link below, you can order it from Amazon. (Taylor K2006 or 2006C which is actually the better buy.)
What kind and size of pump and filter do you have?
Do you have any test kit at all currently? If so, what? Do you have any water testing results?
What all have you used in your pool meaning ingredients and not just product names like 'shock.'
Do you currently have debris on the bottom of the pool?
Welcome to the Pool Forum, by the way!
Currently I'm just using the HTH 5-way test kit from walmart.
Pump: I'm not 100% on the pump. I believe it's a 1 or 1.5 HP Pentair Challenger.
Filter: Hayward Sand Filter
I actually haven't taken the cover off yet. I'm am tonight when I get off work. So I don't have any readings.
I didn't know how long it would take to get a reply, which is why I posted already. :-)
The past 2 years when I opened it was a full algae outbreak. It usually took about 8-12 (maybe more) gallons of "pool" liquid chlorine.
So I was just looking around to see if there was anything different I could do. Any advice is greatly appreciated.
Thanks
1. Go to Walmart or equiv and get 16+ gallons of plain 8% bleach AND a cheap OTO / phenol red drops kit (HTH DPD goes to 5 ppm, and bleaches out somewhere between 10 and 20 ppm!)
2. Physically clean all algae piles and debris. Put pump on recirculate rather than filter.
3. Begin dosing your pool in 4 gallon increments. Retest with OTO after 4 hours of circulation. Repeat dose if chlorine level is less than DARK yellow. Continue this till pool goes from green to gray.
4. Brush the pool completely (even if you can't see!). Make sure the chlorine is DARK yellow before starting. Pool may go green again. Check chlorine after 2 hours -- repeat dose if not DARK yellow.
5. Hold chlorine high 24 hours after brushing. Allow chlorine to drop to 5 ppm. Add a SINGLE dose of whatever clarifer or liquid floc you have on hand. Circulate per instructions, or for 4 hours. Turn pump off overnight.
6. See if algae is going to settle. If it does, let it settle for 24 hours. Maintain chlorine via direct additions. Vacuum piles to waste.
7. Once you've vacuumed what you can OR if it's not settling, turn pump on and begin filtering. Wait at least a week before adding any more clarifier. Do NOT use a 2nd dose of floc.
8. Once you can see your pool returns, you can add a small amount (2 - 3 cups) of DE filter powder to a skimmer. If a cloud shoots out of a return, your filter needs work. If not, you can use repeated small doses of DE to help remove the algae . . . but it will force you to backwash much more frequently.
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How to avoid this? Ask after July 4th.
Awesome!! Thanks for all the information. That is pretty close to what I have been doing the past couple years. Last year was the first year I tried the DE filter powder, which seem to help a lot.
I'm hoping my filter is fine. I just replaced the sand in it about half way through the season last year. I was having to back wash a lot and that is what the local pool store recommended, which after doing that things went back to normal. So I guess they were right on that one. :-)
Well I got the cover off tonight and here are my first readings using my HTH OTO 5 way test kit.
FC: 0
pH: 7.2
TA: 60
Hardness: 150
CYA: 10
Water Temp: 74
Does any of those readings change the course of action you have listed out?
Also my local Wal-Mart has HTH liquid chlorine 10% in a 2 pk of 1 gallon bottles for $5.99. So from what I have been reading on here that would seem to be a lower cost per active oz. Since it's 10% I guess I would only need around 12 bottles of it? If my math is correct.
Would you recommend using HTH liquid chlorine or just stick with plain bleach?
Also I've been reading some of your BBB method. I think I might give it a try this year. Just need to read up on it some more to make sure I understand the process I should follow.
Thanks again for all your help.
Correction on my equipment.
Pump: Pentair 1HP
Filter: Pentair Tagelus TA-60/600 Sand Filter
inline Hayward auto chlorinator
Plain bleach is much more likely to be fresh. That is less of an issue now, than once it gets hot. But if the HTH has been sitting around . . . it matters now. I'm not sure what you're paying for the 8% store brand Walmart bleach, but the prices here would make it, not the HTH 10% cheaper.
How is your pool doing? Did you decide to use the BBB method? If so, did you buy the K-2206 test kit?
The pool is doing awesome this year! Yes I have been doing the BBB method all year with great success. I did buy the k-2206 kit and does seem to be a lot more accurate then the OTO kit.
Hi Mr. PoolDoc,
I forgot you asked me to hit you up after the july 4 for the information or steps I can do this year to help prevent a big algae problem next year when I open my pool.
So is now a good time? :-)
Scott