giving up

[melgna]

Ok I posted fiberglass algae last week and after running my pump for 72 hrs and 12 bottles of bleach I'm giving up. Still no signs of improvement.
I'm going back to the powderd stuff.
Does anyone know the difference between chlor brite and power powder????
I was using power powder and was told that I should'nt use it on my fiberglass pool. Then I was told to use the chlor brite and never had so much problems with my pool being green before.
Please Help.....

[chem geek]

You reported that you had very high CYA levels so only a substantial drain/refill to dilute the water would reduce that. Otherwise, you would have had to maintain extraordinary chlorine levels (40 ppm or higher) to clear your pool of algae. That is not practical to do with high CYA which is why it was necessary to lower the CYA. I suspect that either it was so high that even diluting it didn't lower it enough or the chlorine level wasn't maintained -- it probably got consumed by the algae bloom.

There are other ways to kill the algae, but are expensive, but will work if you can't lower the CYA level. Using a phosphate remover will starve the algae of an essential nutrient.

Chlor-Brite is Dichlor and is absolutely, positively, NOT the thing to use in your pool since it will increase CYA substantially. For every 1 ppm FC added by Dichlor, it also adds 0.9 ppm to CYA. That's part of what you got into this mess, so do not use that product, period. It's only useful if you don't have enough CYA and want to increase both chlorine and CYA at the same time.

Power Powder Plus is Cal-Hypo (calcium hypochlorite) and has no CYA in it. However, it does increase Calcium Hardness (CH), though that isn't as much of a problem in the short term unless your water is already saturated with calcium carbonate. Your CH was at 250 ppm so keep in mind that with Power Powder Plus for every 1 ppm FC you add, you will increase CH by 0.7 ppm. Note that adding Cal-Hypo when the pool is near calcium carbonate saturation will temporarily cloud the water. Lowering the pH with some acid will help clear the water faster, but if the CH level gets too high you'll be back at needing a drain/refill for that.

This is why bleach or chlorinating liquid were the recommended sources of chlorine since they do not add to CYA nor to CH. 12 bottles of bleach in 20,000 gallons only raises the FC by 28 ppm and with your high CYA level and algae consuming the chlorine, that was probably not nearly enough. Again, trying to fight algae with a high CYA level is very, very hard. Shocking to an FC level of 40% of the CYA level means that a lower CYA level needs far less chlorine to kill algae. If you don't get the CYA lowered, then the expensive phosphate removal approach is one of your only bets, other than using a copper algaecide (but then you'll have side effects from copper to deal with later).

Your last post here said you were going to get a full set of numbers. Did you do that? It would be good to know where your CYA level is at right now. The 100+ you started with could have been anything -- 150, 200, even 300 -- so dilution may not have brought it down by very much.

The main lesson to be learned is to not let the CYA level get too high and to prevent algae from occurring early on. I'm sorry the pool store gave you such bad advice and made the problem worse by having you use Chlor-Brite.

Richard

[melgna]

I think one of the problems is that I dont know how much bleach to add at once. Last night I added six btls. No improvement. How do I know how much should be added at one time????
Should I add power powder to work at the green faster then go back to bleach????

[chem geek]

The problem is that without knowing the current CYA level it is hard to know how much chlorine to add. And yes, you can add both bleach (or chlorinating liquid) and Cal-Hypo powder into the same pool water. You don't mix them together outside, but in the pool water it's fine. Generally, with Cal-Hypo you premix it in a bucket of pool water anyway.

In your situation, it might be better to bite the bullet and put in an expensive phosphate remover. Either that or you really need to test the CYA level and do more drain/refill to lower it. You'll have to do that at some point anyway, so might as well drain out some algae while you're at it.

In 20,000 gallons, 10 bottles (96 fluid ounces) of 6% bleach (unscented Clorox Regular or off-brand Ultra) will raise the FC by 23 ppm. It would take about 4 gallons of 12.5% chlorinating liquid to do the same thing. It takes about 6 pounds of Cal-Hypo 65% to raise the FC by the same 23 ppm. Just keep in mind that with an algae bloom, the chlorine gets consumed quickly by the algae, trying to kill it, so more needs to be added to maintain a high level.

The problem is that 23 ppm may not be nearly enough if your CYA is still way over 100, so it just doesn't make much sense to throw chlorine at this situation if the CYA is truly still that high. I would just continue to do partial drain/refill until the CYA gets much lower -- if you can get it to 50 ppm then you can easily kill all the algae by maintaining 20 ppm FC of chlorine. See this post for an example of a pool that was cleared of algae using chlorine alone upon spring opening. Or look at this post or this one.

Also, if you don't have a FAS-DPD chlorine test kit, such as found in the Taylor K-2006, then you can't easily measure high chlorine levels above 5 ppm. A good test kit helps out a lot.

Richard

[mel gna]

After a total of 12/ 96 oz btls and 14/ 174 oz and 4 lbs of power powder the pool is no longer green but very cloudy.
I also drained it about 2 ft twice.
I tried to get my water tested again but leslies said that the chlorine levels were too high and that I wont be able to get accurate results, so I still dont know if mainly my CYA came down yet.
What should I do about the cloudiness and when would be a good time for me to add the metal free since I added more water to the pool?
Last but not least Thank you so much for the advice, I was about to lose hope and even though I used alot of bottles of bleach it still did'nt cost as much as I probably would have continued to spend listening to those at leslies.

[Backglass]

Remember...Powder/chlorine/gas/liquid...it's all chlorine.

Just keep at it. It will probably take more still.

[chem geek]

Well I'm glad you're not frustrated with me as it is taking quite a while to clear your pool and we still don't know it's CYA level. The fact that you had high chlorine would not prevent the pool store from measuring the CYA level. The only test that high chlorine would foul up is pH -- all other tests can still be done with high chlorine levels (the Total Alkalinity test will go from blue to yellow instead of from green to red, but the measurement is still valid).

I do suggest you get yourself your own good test kit, such as the Taylor K-2006 from Taylor here or from Leslie's online here or from poolcenter(dot)com here or the even better TF100 test kit from tftestkits(dot)com here. This should reduce your frustration with pool stores since you won't need to visit them anymore for testing (except, perhaps, for metals).

You can add the metal sequestrant at any time so since you've added more fill water you can go ahead and add that BUT the high chlorine levels might break some of it down so when you are done clearing your pool you'll probably want to add a bit more.

The cloudiness is dead algae. You need to keep the chlorine levels up to prevent it from growing back and to oxidize the algae that is there. To clear it up, you've got several options depending on your patience, type of pool, and budget. If the algae is settling to the bottom of the pool, then you can vacuum to waste to get rid of the bulk of it. If it is not settling, then you can filter it (and brushing the pool sides and bottom helps with that) and backwash or clean your filter frequently. The faster, but more expensive, option that is especially helpful if you don't have a floor drain in the pool and the algae hasn't settled is to use OMNI Liquid Floc Plus where you turn the pump off, add the floc, let it settle overnight, then vacuum to waste the next day.

Order your test kit today and by the time the pool clears it should have arrived and you'll know where you stand with the CYA level. That will then tell you what sort of FC level you need to maintain, or if the CYA is still high then you can use PolyQuat 60 algaecide to keep away algae -- but if you get your CYA to a reasonable level then chlorine alone can easily keep away algae (though the PolyQuat can also be seen as "insurance" just in case the chlorine level drops too low in the future).

Richard

[melgna]

I bought a TF-100 today.
When it gets in I'll post my numbers. In the mean time I'll keep scrubbing and filtering.
Thanks alot guys...

Aloha, Gina

[pool doctor]

you don't mention that you are or are not using an algaecide..................if not you should, and also check for phosphates. All my customers who have persistant algae probs usually end up having phosphates

[chem geek]

Unless the phosphates are extraordinary -- above 4000 ppb -- chlorine alone will control algae (and even at higher phosphate levels chlorine will control algae but needs higher chlorine levels so may not be worth it at some point). See this thread for a discussion about this. Basically, if there are virtually no phosphates (< 100 ppb) in a pool then the pool won't get algae -- that is true. That makes phosphate removers similar to algaecide in that regard in that they are one method of controlling algae. They are not the only method, however. Many pools have high phosphate levels (1000-4000) and do not get algae because they keep the chlorine level high enough relative to the CYA level -- an FC minimum of 7.5% of the CYA level.

In other words, it is not true that if your pool has high phosphates that it will get algae. If proper chlorine levels are maintained, it won't. If you test your pools that maintain proper chlorine levels relative to CYA and don't have algae, I'll bet you find that many have high phosphate levels as well. Phosphate removers are the latest craze with pool stores because they are expensive and there is a lot of profit in them. They do work, but need to be seen as an alternative -- not the only answer.

If phosphate removers weren't so expensive, then they would be a simple and easy way to control algae. They are certainly an option. Using PolyQuat 60 algaecide weekly is also an option. But both options are unnecessary if one maintains the proper chlorine level. It's completely up to the pool owner to decide what works best for them. For those that don't think they can maintain the chlorine level relative to CYA and want some "insurance", then a weekly maintenance dose of PolyQuat 60 is one alternative. Another alternative that is initially more expensive (depending on the initial level of phosphates) is to use a phosphate remover. Some users just want to continue to use Trichlor tabs/pucks where for every 1 ppm FC they add, it also adds 0.6 ppm CYA, so unless they have small pools with regularly backwashed sand filters, the CYA builds up. For such users, an algaecide or phosphate remover is required since they generally won't or even can't keep the FC high enough as the CYA gets really high.

Richard