New homeowner, pool owner lots of q's!

Just subscribed to the forum, and have been battling algae mostly via trips to Leslies, and so I'm hoping to get smarter on pool maintenance. I am overwhelmed trying to learn about pool chemistry, the products out there, and my current algae situation! I've been reading the massive amounts of info on here, but could really use some quick advice for now. I scrubbed, shocked, and vacuumed the pool a week ago, have been out of town, and now I'm back and it's worse than before (algae on the walls and floor, hard to say if it's yellow or green, looks like both?)

I estimate my pool is 25k gallons (hard to say since it's an irregular shape). My setup is 1 chlorine floater (I try to keep 3 3" tabs in there) and a sand filter, and the pump runs during the day for about 12 hours straight. I use test strips, and maybe weekly have Leslies test my water (not sure how accurate the strips are). Here are my latest test results from them:

FAC - 0
TAC - 0
TOT BROMINE - 0
PH - 7.4
TOT ALK - 110
CALCIUM HARDNESS 270
CYANURIC ACID - 100
TOTAL DISSOLVED SOLIDS - 0
COPPER/IRON - 0
PHOSPHATES - 200
SALT - 0

They recommended adding 7 pounds of shock, then wait 4 hours, backwash and use 40 oz of No-phos or Phos-free. A few weeks ago, before the algae took off, I added some Soda ash and Alkalinity Up per their recommendations. Looks like I could have just bought some baking soda :)

So my priority of course is to clear up the algae, but then figure out how to prevent re-occurances. So my questions are:

1) Rather than using shock powder, should I use liquid bleach? 1 gallon bleach (5.25 ppm) per 10000 gallons pool water x 2.5 (since I have a 25k gallon pool) x 2 (to get over 10ppm)? So that's 5 gallons of bleach. Good assumptions? How often should I keep adding these 5 gallons of bleach (not sure if my test strips are a good way to measure that I don't drop below 5ppm)?

2) Should I brush the pool while I'm doing #1 above?

3) Should I drain to waste? Or just monitor my press gauge and backwash as needed? Just worried if I drain to waste I will be draining a ton of water, not sure how long to drain it for.

4) Is reducing my phosphates that important? I've read on here that it's no issue if you keep your chlorine up, but I also read that phosphates and nitrates are algae food, and as long as you have those you'll have algae problems. What should I do??

5) Is my one floating chlorinator enough? Or should I add an inline Rainbow chlorinator?

6) Any other things I should do to prevent algae re-occurance, or other chemicals I need to add?

7) Maybe unrelated, but would adding a DE or other type of filter help??

Thanks!

Wow. You need chlorine ASAP. With a cya of 100 (and it actually is most likely over 100 but 100 is as high as the test will differentiate) your shock level is 25ppm. You need 11 gallons of 6% bleach in there to get it up to shock level. You are gonna need a lot of bleach. If your pool store sells liquid 10 or 12% chlorine, that might be a good choice for this big pool, but don't let them talk you into buying anything else.

No more trichlor pucks or dichlor powder shock for this pool as they will continue to add cya and your is already through the roof. Cal-hypo adds calcium and you don't need any more of that. (Is this a vinyl pool?)

Test strips are not gonna work. First of all, they are not reliable and secondly they will not test anywhere near as high as you are gonna need to go. You need to get a good test kit quickly. Take a look at this link for more info. We recommend the Taylor K-2006.

http://www.poolforum.com/pf2/showthread.php?t=10006

In the meantime, go and pick up a cheap test kit from Walmart. You can use a dilution method to force it to read higher than the 5ppm limit it will show. Take a look at this link for information about how to do this.

http://www.poolforum.com/pf2/showthr...5545#post65545

Don't worry about anything else right now but chlorine.

Actually, with your cya so high, you are gonna have a really hard time keeping algae at bay. If it were my pool, I'd do a partial drain and refill and see how low this takes your cya. I'd drain 1/2 to 2/3 of the pool. Depending on how high your cya actually is, it may take a couple of drain/refill cycles to get the cya down to a more manageable level. Do NOT drain the entire pool at once though.

Forget phospate products or anything else. Right now, just keep adding chlorine to keep the cl level at 25ppm. In a 25K pool, each gallon of 6% bleach will raise your cl by about 2.5ppm. Test as many times a day as you can and each time add enough bleach to get back up to 25ppm. There is no such thing as testing and adding bleach too much when you are fighting algae. The more often you do it, the better and faster it will go.

Sand filters are great. A DE filter isn't gonna keep algae at bay any better for you. Your problem is that your cya is so high and you aren't keeping the cl level high enough to compensate for that high cya. Run your pump 24/7 right now. If you have lots of gunk that can be vacuumed up, vac to waste. Otherwise, just watch the filter pressure and backwash when the pressure rises 8-10psi over clean filter pressure. Also, yes to brushing the pool daily.

Get a good testkit ASAP. Repost with further questions and new numbers when you test.

Thanks! Quick piece of info, the pool is plaster.

Why would the CYA levels get that high? Is it from allowing the chlorine levels to drop that much?

In general, do I need an inline chlorine feeder, or is the 1 floater sufficient?

The CYA levels are that high from using the trichlor pucks. They are stabilized which means that they add CYA. For every 10ppm of chlorine that is added from a trichlor puck, 6ppm of cya is also added. If you use those pucks over a long period of time, they cya level continues to rise until it gets really high like yours is. People do not understand that the more cya they have, the higher they have to keep their chlorine levels or else they will get algae. We see it ALL the time. That is why I say no more pucks for your pool. Not in a floater nor in an inline feeder. Also, nor more dichlor powder shock. It adds 9ppm of cya for every 10ppm of chlorine added. You need to switch to liquid chlorine. Either bleach of pool store liquid chlorine.

I suggest reading all the "stickied" threads at the tops of most of the forums. Especially in the chemistry areas of the forum. You will learn a lot about the basics of pool care. Also, the sister site to this forum has lots of good information. I suggest also reading there ---- www.poolsolutions.com

Thanks....I was just reading some of your posts on trichlor and CYA (and I just bought a bucket of trichlor, doh!). Since I have the bucket of trichlor already, could I use use it profusely until it's gone, and then switch to liquid chlorine? Any harm in high CYA levels, other than eating chlorine? I'd hate to throw away 60+ pounds of trichlor. But good advice on the liquid chlorine. I assume it's not stabilized though, so wouldn't I have to add CYA at some point to prevent the UV from burning off the chlorine? Or is there a preferable stabilizer to add?

Maybe a stupid question, but do SWGs generate CYA?

You can use the trichlor, but it will continue to make your cya get higher and higher and higher. Who knows how high your cya is?? A reading of 100 (since the tester cannot differentiate any higher) could really be 200? 300? ????? You can use the pucks but it is going to be hard to manage your pool. You will have to run extremely high chlorine to compensate for the high cya. Take a look at this chart:

Stabilizer . . . . . . Min. FC . . . . Max FC . . . 'Shock' FC
=> 0 ppm . . . . . . . 1 ppm . . . . . 3 ppm . . . . 10 ppm
=> 10 - 20 ppm . . . . 2 ppm . . . . . 5 ppm . . . . 12 ppm
=> 30 - 50 ppm . . . . 3 ppm . . . . . 6 ppm . . . . 15 ppm
=> 60 - 90 ppm . . . . 5 ppm . . . . . 10 ppm . . .. 20 ppm
=> 100 - 200 ppm . . . 8 ppm . . . . . 15 ppm . . .. 25 ppm

Trichlor pucks will not go bad as long as you keep them dry. You can put them away for the summer and save them to use next year if your cya level is low enough to permit it. Your call. I would not suggest continuing to use them but if you decide to, just be aware that your cl levels will need to be really high all the time and you may have a lot of trouble keeping this pool algae-free.

Liquid chlorine is not stabilized. You have so much cya in there already that you would not need to add more. (It does not go away. The only way to get rid of it is to drain and refill.) SWGs do not generate cya.

Hope this helps.