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Thread: Need help with Algae and Absorbic

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    Need help with Algae and Absorbic

    I followed the stickie on treating stains with absorbic acid. Yes, it did remove all the staining, but my water went from clear to cloudy, then cloudy to green. Now I've got a pretty ugly mess and I'm not sure if it's the staining coming back or algae or both! I did pre-treat with Algaecide; but obviously not enough. And a sequestrant after the acid treatment; but now I'm wondering if that was enough!

    In short, my IG plastic stairs/steps look 'stained' again to me; but it could also be the alage. When I use just a little bit of absorbic on it (test), the acid does clear it up some. Can Absorbic Acid clear up alage as well??? (I did this after brushing). So now I'm lost since I feel like this time around on the acid treatment I waited well past 48 hrs prior to addidng any bleach. Even then I've only been using 3" tabs in my feeder and every other day adding 1/2gal of bleach. The pool is a 30,000 gal vniyl pool.

    Last numbers I have are:

    TC: 0.1
    FC: 0.1
    CYA 57
    Alk 125
    PH 7.4 (which am lowering to 7.2 as we speak)


    The acid was put in about 1 week ago. So, I'm at the fork in the road on what to do? Should I reapply what acid I have left in a cheap attempt to start over (I only have about 1 pound left). Rasie the CL or ?

    Green isn't my color .

    Thanks! Lee
    33000 IG Vinyl, Sand Filter, Circupool SWG, Polaris 180 w/Booster Pump, Mosquito Misting System, Home Automation

  2. Back To Top    #2
    JasonLion's Avatar
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    It is very common to get algae when doing the ascorbic acid treatment, no surprise there.

    If you don't have enough sequesterant in the water the stains will come back as soon as you raise the PH or add bleach. The big advantage is that if you lower the PH a little and add more sequesterant that normally takes care of it very easily without doing the entire sequence again.

    You could try spraying a garden hose at a small area to see if you can clear up the water enough in that spot to see if there really are stains.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
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    mbar's Avatar
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    JasonLIon is right - Lower the ph - adding sequestering agent will lower the ph too. After the ascorbic acid you should start to add bleach, you should take it right up to the level you need for your cya, which in your case would be 5 to 10 ppms. You do this slowly, and watch to see if you are getting any stains - it is hard to get chlorine to hold after the ascorbic stain treatment, so you have to be consistent with testing and adding to take it up to your levels. If you see stain start to form, you add more sequestering agent, and keep the routine till your bleach holds.

    Now that you have algae, you will have to shock the pool again. It will be ok - just add more sequestering agent, keep your ph low and shock. If you see stains start to form, add a little more sequestering agent. Your water will probably get cloudy again - from the dead algae, and the sequestering agent. Keep the filter running 24/7 and backwash often. Keep the chlorine at shock level 20ppms for your cya, until the algae is dead (your chlorine holds overnight). If the water is cloudy after 2 days, you can use a floc to get rid of the dead algae. Keep me informed, I can help you get through this, don't get frustrated, it is a learning experience to figure out how to keep the stains away. Just ask any questions you have.
    16x33 fiberglass pool sand filter

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    Why don't we recommend adding an initial dose of PolyQuat 60 to the pool before starting the ascorbic acid treatment? The initial PolyQuat 60 will even reduce chlorine levels if they are high and will prevent algae from forming for at least a week even if there is no chlorine present (or very little chlorine present, as with the < 1 ppm FC recommended for the ascorbic acid treatment). I can't guarantee that the PolyQuat 60 won't interfere with the treatment, but I don't see how it would.

    Richard
    16,000 gallon outdoor in-ground 16'x32' plaster pool; Pentair Intelliflo VF pump; Pentair IntelliTouch i9+3s control system; Jandy CL-340 square foot cartridge filter
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    mbar's Avatar
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    Hi Chemgeek, I do have adding polyquat 60 in the ascorbic acid sticky. It is a good idea. The only thing the poly 60 will do is eat chlorine, which with the ascorbic acid treatment the chlorine is at 0 anyway I do think that I am going to change the sticky to read start to raise the chlorine after 24 hours instead of 48. I have tried it in my own pool, and as long as all of the stains are gone, it is ok to a start to raise the chlorine as long as it is done slowly, watching for stains. It is very hard to get the water to start to hold chlorine anyway - since the chlorine has to breakdown the asocorbic acid that is in the water. As long as the ph stays around 7.2, any stains that start to form can be taken care of by adding more sequestering agent. Otherwise, it seems to be a vicious circle of doing the treatment, getting algae, and having to shock then the stains return This way you can add the sequestering agent in if you see stains, so you know there is enough in the water. Sequestering agent gets consumed by shocking the water too. That's why dealing with stains is so frustrating What I have found in my experience is that while doing the treatment, and right after, keeping close watch and getting the water balanced very quickly is the best way.
    16x33 fiberglass pool sand filter

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    Thanks for all the information and replies. I did add an algaecide prior to treatment (but now I do not think it was enough, or the 100+ temps just killed me). I have added another 2 bottles of alagecide, added sequestrant, now I am adding CL to assist in getting rid of the algae. I believe there are stains reappearing, but I'm not 100% sure since the algae is there as well. I'll try brushing and seeing where the addition of CL takes me. Personally, I think I've got continued staining . I lowered my PH by formula, will check again later, but I know it has not gotten above 7.4. I'm striving for the 7.2 range. Oddly, my Alk and PH haven't been that hard to control throughout all this.

    As far as your stickie goes, some guidance about what defines 'slowly raising' CL might help (would have helped me). By that I mean what would be the most one would put in at any given dose and how much/many doses per/day, etc.

    Anyway, I appreciate the help and will be bumping this over the next few days since I'm far from out of the woods!
    33000 IG Vinyl, Sand Filter, Circupool SWG, Polaris 180 w/Booster Pump, Mosquito Misting System, Home Automation

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    mbar's Avatar
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    By slowly raising the chlorine, I mean using bleach and take it up to the low end of your "best guess chart". I like to use bleach, because you can use as little or as much as you want more easily then the pucks, or even bags of shock. You know that 1 gallon of 6% bleach will raise your chlorine by 6ppms in 10,000 gals of water, so if you have a 20,000 gal pool and want to raise it up to 3ppms, then you would use a gallon. The trick is to check it often, because just like algae, the chlorine will be eaten up by the ascorbic acid that is left fast. You just want to make sure all of the stains are gone before you start to raise the chlorine, keeping the ph down at around 7.0 - 7.2. , so you have to check often until the chlorine is holding. You will get a feel for how long you can go before another dose is needed. If you see stain forming, then add more sequestereng agent right away. Hope this helps, feel free to ask any other questions you may have.
    16x33 fiberglass pool sand filter

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    Here is my latest numbers and situtation.

    FC 0.5
    TC 0.4
    Ph 7.3
    Alk 66
    CYA 30

    I had the CL up yesterday over 10ppm (my max test), so obviously it is being used up with the algae and everything else. I did add some more seq to hold stain's out, but I still have light-medium staining all around . I know my CYA is a little low, and I'm raising it via 3" tabs. Luckily I only get half sun at best...so it's not too bad I suppose.

    I plan on bumping up my CL again and again over the next few days. The algae is starting to clear although not all gone yet. I do want know what else I can do (if anything) to help with the remaining stains. I'd hate to do this whole treatment again and won't until cooler weather prevails. I don't think I could have picked a worse time to do this <arrgghh>. Any suggestions on what else I can do to relieve the remaining stains? (I already lowered the PH once and added the seq again...but it didn't really help).

    Thanks!!!!!!
    33000 IG Vinyl, Sand Filter, Circupool SWG, Polaris 180 w/Booster Pump, Mosquito Misting System, Home Automation

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    mbar's Avatar
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    So sorry to hear of all the problems, I really can relate What I would suggest is to take the alkalinity up to 80 with baking soda, and the ph down to 7, and continue with the bleach until all of the algae is gone. Once the algae is gone, you can keep the ph low, and add more sequestering agent. Just keep the ph down around 7 - 7.2 and when the chlorine comes back down to normal range, I think most of the stains will disappear. Keep the filter running 24/7, and backwash often. Let me know how you do, I know it is frustrating, but you will get the stains under control, and the water clear
    16x33 fiberglass pool sand filter

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    I'm going to try your suggestions. Algae is mostly cleared up. Water is clear, but I think there is still a little in there, so I plan on killing it out for another day or two. I had quite a bit to vacuum up and I'm sure with additional brushing I'll have more. I don't have today's readings, but yesterday my CL had gotten eaten up quite a bit. Alk was down to 69 and CYA 29. PH still holding around 7.3. I'll do as you recommend in a day or two. The stains are without a doubt there....so I'm a little depressed for sure. I know they will go away with additional absorbic...and I've thought about putting a little bit in on the stair or something...what do you think? The bottom (deep end) is still quite bad though. I am raising the CYA through pucks on a continued basis. I had to add water from evap and backwash (it's hot here).

    Thanks for the continued help....hopefully I can get out of this with my skin alive (wife about to shoot me at times!)
    33000 IG Vinyl, Sand Filter, Circupool SWG, Polaris 180 w/Booster Pump, Mosquito Misting System, Home Automation

  11. Back To Top    #11
    mbar's Avatar
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    I would just continue as you are - raise the alkalinity, keep the ph low, and blast it with bleach. You don't have to worry about the cya - 30 is ok. Don't put any ascorbic acid in right now, as it will use up the chlorine, and that isn't what you want to do right now. You can do it later, after you get all of the algae cleared, and the water balanced. I did it myself a couple of times. Just add a little bit near the stains, put the filter on circulate for a couple of hours, and then back on filter. Just be very consistent with the chlorine afterwards, and make sure it doesn't go too low. But for now, even though it hurts, just leave the stains there so you can get rid of the algae. You will be surprised that after the water is balanced and the chlorine goes back down (with low ph), the stains just may disappear on their own
    16x33 fiberglass pool sand filter

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    Mbar,

    Thanks for the information and help so far. I wanted to update you (and anyone else) on what's going on. I have been keeping the CL high and brushing on a regular basis. The water is back to crystal clear and I have vacaumed most of the algae out of the pool. I am still trying to keep the CL fairly high to ensure all problems gone, but it seems to be at the right spots. The latest numbers are:

    CL 7.1 (total and free)
    PH 7.3
    Alk 78
    CYA 23

    The stains are still around, some are lighter, some are not. It's not like they are all gone, but I am still keeping the CL up a bit and hoping that time and circulation will do something for me. Do you suggest I do anything else to assist with the stains? It seems the lower PH and Alk aren't as comfortable on my eyes in the pool, but it's nothing I can't live with for a bit.

    Let me know your continued suggestions.

    Thanks!
    33000 IG Vinyl, Sand Filter, Circupool SWG, Polaris 180 w/Booster Pump, Mosquito Misting System, Home Automation

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    mbar's Avatar
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    You can take the alkalinity up to 90 - 100, and add some more sequestering agent - this should bring your ph down. You can take the ph down to 7.0 -7.2 and keep the water circulating. The low ph should help lift the stains with the sequestering agent. The higher alkalinity should help with the eyes. The chlorine is good! I think adding the sequestering agent should lighten the rest of the stains, but if after a couple of days the stains are still there, just add a little more ascorbic acid near the stains. Just a little should not unbalance the water like before. The chlorine will eat up the ascorbic, but it should get rid of the remaining stains before it does. Just keep an eye on the chlorine and don't let it drop. Sometimes double the dose of sequestering agent is needed - so don't be afraid to add it. It will bind with the metals that lift off, and the rest will just eaten up. Just watch the chlorine, because the chlorine gets used up by the ascorbic and sequestering agent. I know it's a vicious circle , but once the stains are gone, and the water is rebalanced, you will be able to keep the stains away
    16x33 fiberglass pool sand filter

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