Heavy Green Algae, Getting Ready to SLAM, Running out of Time - Suggestions?

Sep 25, 2013
28
Hi Everyone -

Wondering if you can give me some pointers to try to clear the water as quickly as possible, as we are running out of swimming season in CT and my daughter would like to have a pool party in the next 2 weeks. However, JUST uncovered pool 2 days ago - long-story short: had to re-run some electrical lines and re-plumb lines near filter. FINALLY got electrical work and plumbing completed Wed, uncovered pool and turned on pump, which has been running 24/7 since.

- Have been reading various posts on others' algae issues, read instructions on SLAMing, scanned Pool School, using calculators to determine chemical requirements, etc, but need some guidance on best approach to get rid of this SEVERE algae issue.

- 16x32' IG vinyl liner pool w/steps - ~22,000 gal?

- Sta-Rite System 3 (200lb) sand filter - just filled with new sand last week. Previously had Zeolite, but kept having trouble with algae last 2 years - decided to go back to sand. . . and see if it makes a difference. Don't know if it has any affect at all - always assumed Zeolite was better.

- Pool has HEAVY green algae. Can only see the first step in the shallow end. Everything below that is invisible at this time.

- I could see deeper into pool when I first pulled off cover, but as soon as filter started stirring water it's a deep green swamp. Assume sunlight hitting water also helps multiply algae bloom? Pool is in partial shade, so doesn't get all-day sun.

- Filter running at 15psi normally, typically loads up and is running 22-25psi within 2-3 hours.

- I vacuumed the entire pool and walls yesterday to get as much as I could. Filter would load up within minutes and require backwashing constantly. No leaves or heavy debris at bottom that got trapped in basket - just dark green water during backwash.

- Also have my Aquabot cleaner running all day. Have to pull it out every couple hours and clean bag. Heavy, slimy algae inside bag - hasn't picked up anything else (leaf debris, etc.).

- Water parameters were spot-on when I closed pool last year. However, seems they have drifted way off over winter. We had lots of snow, etc, which must have changed water chemistry, etc.

- Unfortunately, I only have AQUACHECK 7 test strips. I know I will get yelled at :hammer: for not having the proper test kit. I have a Taylor K-2006 kit on order with my local warehouse - should be here Tues. I realize it will be difficult to accurately monitor Free Chlorine levels with the test strips, but would like to get started SLAMing today, if possible, unless everyone tells me differently.

- Don't want to pour $100's of dollars of bleach/chemicals into pool only to find out afterward that I need to change out my water, etc. Also. . . .we only have perhaps 3-4 weeks max of swimming left here in CT, so don't want to spend $100's on chemicals + electricity to run pool 24/7 to find out I couldn't even swim in the pool at all - kind of a waste - I might just as well cover it now, call it a day, and attack it next Spring (which would keep me in the dog house with family! :( I know all is not lost. . . . but looking for advice, best way to attack the algae.
Should I simply empty pool a couple feet and replace some water (maybe changing out about 1/3 of water) - I know to leave at least 1ft in shallow end to prevent liner float, etc. Water is now quite expensive here, so this isn't a cheap option either. I realize pools aren't cheap to maintain, but don't want to needlessly waste tons of $$ for a few swims left this year. Wife and daughter are already upset it has taken this long to finish electrical and plumbing work req'd.
Or, should I start attacking algae with shock and leave water as-is?

- Didn't want to start shocking and pouring chemicals in until I had cleaned out what I could, and since filter is pulling out lots of algae every hour, thought it would be better to get rid of some, rather than having it consume all the chlorine. Or. . . . am I being stupid and fighting a losing battle while algae multiplies itself with no chlorine in the water? Also, didn't want to start, if you don't think I can really monitor my FC levels enough to do a proper job on the SLAM. However, if algae is just multiplying while I sit here on the computer, I need to do something to start, and quick.

- Here are current readings from AQUACHEK 7 test strips:
TOTAL HARDNESS: slightly over 250
TOTAL CHLORINE: 0
FREE CHLORINE: 0
PH: 6.8 (I just added Soda Ash to raise to 7.2, as suggested)
TOTAL ALKALINITY: 80
CYA: 0 (am dissolving CA granules as we speak and will add to sock near return) - target is 30 correct?

** What are my first steps, after what I have done so far? Shock? Exchange water? Wait till next week for test kit? Other suggestions?

**Don't want to shock too high and bleach my relatively new liner (2nd full season). Target FC is 16 for SLAM, correct?

I will keep vacuuming, brushing, running my Aquabot, and backwashing (spent most of the day yesterday doing all of these!). However, this looks a little bleak, based on how long it took lots of others to clear up their water, which didn't seem as bad to start. Any advice would be greatly appreciated and let me know if you need any additional info regarding my pool, equipment, water, etc.

Thank you all in advance!
 
Goto the store and get as much bleach as you can. 10-30 gallons of 8.25%
You will likely go through 25-40 gallons by the time its done.

Pool at the house I'm moving out of was 23,000 gallons.

1 gallon would raise it by 3ppm.

going by that rough figure you should keep the filter running as much as possible and pour in at least 5-6 gallons daily to get
started.

CYA 30 sounds right.

Very important that any debris or leaves / organics be removed before you start.

You will likely run out of free chlorine test reagents quickly (that taylor kit doesn't have much for what you will need to finish the slam)
so probably a good idea to order more R0870 & R0871
 
Without a proper test kit, I would not add anything to that pool except 1 to 1-1/2 gallons of bleach each day until your test kit arrives.

DO NOT add any CYA (stabilizer), the test strips are notoriously way off when measuring CYA & you could just be making matters worse for yourself.

If the algae is as "SEVERE" as you are describing it will probably take a couple of weeks to clear completely.

Pictures would help.

Dom
 
If you have time to keep on it frequently, you will make progress more quickly. Adding CYA to get to 30 sounds right.

If you want to give it a try (starting while waiting for your test kit), here's something you could consider... Last year I ran out of FAS-DPD reagents in the middle of a SLAM, and I continued as best I could using my OTO kit (that's the simple drop based kit, one side yellow for chlorine, the other side red for pH - a kit you can pick up at most hardware stores during the summer). I diluted my pool water samples as carefully as I could, and I used a 20:1 dilution, in order to get down into the more sensitive range on the OTO kit. Then I multiplied by 20 to get my approximate chlorine levels, and dosed with bleach to get back to my SLAM target. When the new reagents arrived several days later, I compared the FAS-DPD reading with the reading I got with the OTO approximation - they were quite close, with the diluted OTO result being slightly low (i.e. off in the safe direction as far as keeping up SLAM levels).

Couple of caveats - the dilution does introduce inaccuracy, and you can't measure FC and CC separately. Also, doing the careful measuring and mixing for dilution every hour or two (for best effect during the start of a SLAM) gets old. It was preferable to just waiting and doing nothing, however, and worked better than I expected it to.

If you are interested, I can try to remember how I did the dilution process.

The only reason I mention this at all is that you do have a good test kit on the way, so this alternate approach only needs to be a stopgap.

edited to add - Dom points out another important issue - can we really be sure of the 0 CYA? It sounded plausible, given the history and the green swamp you are seeing, but the confirmation is from unreliable test strips. WalMart sometimes carries the hth 6- way drop kit, which includes a CYA test - you could see if you can still find that at this time of year.
 
5/14/15:

Aquabot in all day. Still pulling out heavy/slimy algae - need to wash bag every few hours.
Pressure still building in filter rapidly and requiring backwash every 2 hours or less with very green water output
Vacuumed entire pool and brushed afterward.

Remember. . . . this is all AQUACHEK test strip data
Earlier in day:
TA: 250+
TC: 0
FC: 0
PH: 6.8
TA: 80
CYA: ~0

5pm:
Poured in 3 gal. 12.5% shock

6:30pm
TC: 10
FC: ~0
Poured in another gal. will re-test in 1/2 hr.

Here's a couple pictures of the Frog & Water Bug Oasis - hopefully "Sparkling Oasis" next week???
IMG_2891.jpg

IMG_2892.jpg
(sorry for sideways picture, can't figure out how to rotate it on the blog). . . you get the idea - can only see top step.
 
PH tests are generally not accurate with FC above 10. Don't test or adjust PH when FC is above 10.

Testing and adding bleach every 1-2 hours helps to speed the process.
 
Yeah, I had read previously regarding not testing PH when FC was above 10. However, my FC is still around "0", so figured it was still fairly accurate and PH could stand to go up some. Was ~6.8 earlier in the day, so figured I would bump it up anyway to the recommended 7.2 target.

**Since my FC never seems to go above "0" am I still way "too low" and should I be shocking harder? Just afraid of bleaching liner. . . . but think all this algae will stop it from getting to high anyway. Could smell chlorine a little bit for the first time a few hours ago, instead of strong odor of algae/swamp.

9:45pm
TC: ~10
FC: ~0
Poured in another gallon of 12.5% shock

- Will also go get water tested at Leslie's in AM, just to see how it compares to Test Strip results. Not going to get "pool stored" (I usually stay away from those places anyhow). . . .just getting water tested and will stay on track with whatever recommendations you guys make for me.
 
8/15/15:
7am: Poured in 2 gal. 12.5% shock
Filter at 25psi - backwashed. Aquabot full of algae again - cleaned

7:30am
TC: ~10
FC: 3

I finally see something other than "0" for FC! Was beginning to wonder if something was wrong with test strips

I can barely make out the 2nd step. However, there is less water in the pool, as well. Seems like there is a little bit of progress. Light green tint, instead of darker green.
 

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Just want to say "You are doing good!" Things will be better once test kit gets there. Here is an idea. Collect some pool water into a container. Like a measuring cup. Add an equal amount of plain (filtered would be best) water. Use guess strip in that and double the readings. It might work...
 
8/15/15:
7am: Poured in 2 gal. 12.5% shock
Filter at 25psi - backwashed. Aquabot full of algae again - cleaned

7:30am
TC: ~10
FC: 3

I finally see something other than "0" for FC! Was beginning to wonder if something was wrong with test strips

I can barely make out the 2nd step. However, there is less water in the pool, as well. Seems like there is a little bit of progress. Light green tint, instead of darker green.
If Tc = 10 and fc = 3, that means CC is 7. :shock:

Just eliminating that CC is going to take a whole lot of bleach. That CC is also what you're smelling. Take your time pouring the bleach into the return stream, and then go around with the brush to set up cross currents and expose any algae that has grown the protective slime. It will mix better and kill algae better if you do, and minimize any chance of liner bleaching from too much bleach in one spot.

Keep those pictures coming! You'll probably need to open some photosharing account to hold them all. Posting Photo's Tutorial
 
Thanks for the feedback. Unfortunately, life got in the way and was out all morning. Just got back, so going to be a bit behind. However, I do see progress today. Pool is cloudy grey now, instead of green. Guess that means algae is dying!! Was a little "grayer" before I left earlier. . . think I lost a little bit of ground while I was gone.

Aquabot stirs up water pretty good as it crawls around, and I will be vacuuming and brushing again this afternoon.

I have been trying to pour slowly over the returns. I actually have the V-Fitting venturi-type returns on the pool. They are pretty impressive how much more circulation they provide and seem to get the water circulating deeper in the pool. Have been happy with these the past few years.

Took water to Leslie's at 10am
They didn't give me the results on paper, but here's what I remember:
TC: ??
FC: 3
PH: 7.6
CYA: 45
TH: 240
TA: 100

Tried to sell me some "dead algae water clarifier" "Clear Aid??", which I refused. They told me my chemicals were "right on" and didn't recommend anything other than trying to sell me the water "Clarifier".

Guess the test strips were off on the Stabilizer/CYA. However, I added 1.5 lbs dissolved CA granules yesterday, which I think helped bump it to a "reasonable" level?? And. . . I will need to add more water soon with all the backwashing that has been req'd.

2:30pm - just poured in (1) gal 12.5% shock

2:50pm: (water taken from opposite side of pool that I poured shock into)
TC: 10+ (think I will try the 50/50 dilution method suggested and see what I get next time)
FC: ~7

Here are some pictures from 15 min's ago. As I said you can definitely see an improvement, and can make out the 2nd stair (however, water level is indeed lower than yesterdays pic).

IMG_2894.jpg

IMG_2896.jpg

Please keep sending me suggestions.
 
Didn't get a chance to post yesterday. However, there is obviously good progress.

- Green tint in water is gone. Now water is a cloudy gray.

- Filter is not loading up every 2 hours with green algae - went all day yesterday after a backwash and remained at 15psi. Which means I wasn't babysitting the filter all day and night and actually went to bed on time. However, since it went all day without increasing in pressure (even this morning it was at 15psi) - doesn't seem to be pulling out the level/concentration of algae it was when water was green. I backwashed today (Monday), just to rid filter of algae - just in case. However, I assume I can let it go (days?) until I see pressure rise, or should I keep backwashing daily at this point, due to the algae problem????? What do you recommend?

- Aquabot filter bag collection also changed from slimy green algae to gray algae, and not loaded at the same amount. The dead algae is significantly "lighter" in weight, and the robot is now climbing the walls and operating "normally". Before it seemed like it would get stuck every one in a while on a slope, etc - probably due to both weight of algae in bag and sliminess of walls.

- I brushed the pool twice yesterday completely to remove algae from surface. Didn't have chance to manually vacuum - but Aquabot has been running pretty much 24/7.

- Yesterday was first day that FC levels were up to near SLAM levels and would hold for hours.

- I can just barely make out the shadow of the 3rd stair today (Monday).

- This is the point I've have problems in the past. How do you rid the pool of the cloudy gray algae? Just keep filtering/vacuuming? I will obviously continue to shock, etc. But seems like it's much slower to clear always when it gets to this point. Just keep doing what I'm doing, or other suggestions/next steps??

Here is data from yesterday (Sunday 8/16):
10am - added 2 gallons of 12.5% shock.

10:40am
TC: 10+ (highest test strips would show)
FC: ~20

3:15pm
TC: ~8
FC: ~10 (I know this isn't correct, but best I could estimate from test strips). Used 50% dilution method this time.

7pm - added gal. of 12.5% shock

9pm:
TC: ~16 (50% dilution method)
FC: ~14

8/17 (Monday):
9:30am - added gal of 12.5% shock

11am:
TC: ~10 (using 50% dilution method & test strips)
FC: ~10

Now, since I have run out of upload space - need to figure out how to load images from my OneDrive or Snapfish account. I'll post pictures as soon as I figure it out.
 
You are experiencing a common phenomenon, and not just in the realm of pools. The first 90% of a project only takes 10% of the time. The last 10% takes 90% of the time. A carpenter can frame and roof a house in a couple days, and it looks like a house. It's all the rest of it that isn't so visible that takes forever. Car restoration: how many "projects" get as far as primer and then sit?

Consider the CYA test. See how the graduations on the view tube get further apart as they rise? It's the same as what you're doing: looking through cloudy water. You're down at the bottom now. The difference between 100 and 80 is nothing to the eye. So you are making progress. It's just not visible to the eye yet.

The key now is to keep the water going through the filter so it can grab the stuff. The aquabot probably does a good job keeping things stirred up so the skimmer can draw it in and the filter can strain it out. It's just a matter of opening a can of POP.

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Pool Owner Patience.
 
Thanks for checking in. I have patience on this one! Just wanted to make sure I didn't need to do something else. I'll keep at it. Just seemed strange how filter would rise in pressure 10psi (to 25psi) within minutes when vacuuming or in 2 hours (if I wasn't vacuuming) and needed backwashed every 2 hours, and all of a sudden can now go more than 24 hrs. only rising (0-1)psi. Live vs. dead algae sure must make a difference in how it's trapped within filter media (sand).

Aquabot does a decent job pulling algae out as well, so I'll just keep that guy in there 24/7 and running the filter until clear. It's just a PITA to keep washing out filter bag every cycle. . . . . but all part of the deal!
 
- Filter is not loading up every 2 hours with green algae
[...] doesn't seem to be pulling out the level/concentration of algae it was when water was green. I [...]However, I assume I can let it go (days?) until I see pressure rise, Yesor should I keep backwashing daily at this point, due to the algae problem????? At this point your filter needs to just do it's job, and with the dead algae [which is now small individual withered cells, and no longer clumps and globs of thick, slimy, plump, living cells] it needs time. A sand filter works best when it is a bit dirty, so backwashing too often can make it less effective.
Sometimes you can give your filter more cleaning power by using a little bit of DE. I'll explain how below.*

- Aquabot filter bag collection also changed from slimy green algae to gray algae, and not loaded at the same amount. The dead algae is significantly "lighter" in weight, and the robot is now climbing the walls and operating "normally". Before it seemed like it would get stuck every one in a while on a slope, etc - probably due to both weight of algae in bag and sliminess of walls. Bingo!

- I brushed the pool twice yesterday completely to remove algae from surface. Didn't have chance to manually vacuum - but Aquabot has been running pretty much 24/7.

Good... I'm not sure how "fine" the bags are on that unit? Can you get or use bags that are of a tighter weave... like a skimmer sock is?
Oh and use skimmer socks. ;) They really work!


- This is the point I've have problems in the past. How do you rid the pool of the cloudy gray algae? Just keep filtering/vacuuming? I will obviously continue to shock, etc. But seems like it's much slower to clear always when it gets to this point. Just keep doing what I'm doing, or other suggestions/next steps??
Just wanted to make sure I didn't need to do something else. I'll keep at it. I know it's hard to not fall into the trap of feeling like you need to do something *more*... that's how the pool stores get you... because we all have a desire to get something done faster... or to feel like we are *doing* something besides watching paint dry-- er... the pool clear. Oops-- it's about the same thing, though.. Just seemed strange how filter would rise in pressure 10psi (to 25psi) within minutes when vacuuming or in 2 hours (if I wasn't vacuuming) and needed backwashed every 2 hours, and all of a sudden can now go more than 24 hrs. only rising (0-1)psi. Live vs. dead algae sure must make a difference in how it's trapped within filter media (sand).This is exactly right! In a cartridge or DE Filter it can get clogged in an hour or less if it's live algae... sometimes people have reported DE filters getting so completely clogged, that it choked the pump in less than 5 mins! :shock:

Aquabot does a decent job pulling algae out as well, so I'll just keep that guy in there 24/7 and running the filter until clear. It's just a PITA to keep washing out filter bag every cycle. . . . . but all part of the deal!
*Here is how to use DE (available at places like Home Depot, Lowe's, Ace Hardware, and Pool stores) to increase how well your filter can remove the dead algae [if you try it with live algae... the filter usually will clog almost instantly]
  • Begin by backwashing, and rinsing your filter.
  • Make careful note of clean filter pressure immediately after backwash
  • add approximately 1/4 -1/2 cup DE through the skimmer
  • watch filter pressure over the next 1/2 hour or so... you are looking for a very small increase-- no more than 1 psi.
  • if there is no increase at all after 1/2 hour, or if there is not a 1 psi increase after 1 hour, add another 1/4 cup
  • continue to watch and add DE until you see a 1psi increase in filter pressure
  • it generally takes up to 15-20 minutes after you have added DE to see the psi increase
  • sometimes it takes a little longer to see the rise in filter pressure and there can be a sudden spike after up to an hour-- so try not to rush the process.
  • If you do overshoot the amount and end up with too much of a psi increase, simply do a quick backwash and start over,
  • Really large sand filters may need 1.5-2 cups, but most filters need 1 cup or less.
  • You don't have to add enough to see an increase in pressure, even a little bit of DE can make a difference-- I do this when my water needs just a bit of "polish", such as when there have been several monsoon storms back-to-back
  • Keep track of how much you have added, because the next time you backwash, the DE will wash out of the filter and if you still need/want it, you'll have to add more again
    [*]When you add it on subsequent occasions, start with about 75% of what you think you'll need, and add the last 25% very carefully... watching the psi after every step. Don't assume it will take the same amount every time.​

    If you have more questions, just ask...
I think you are on track-- your pool didn't get mucked up overnight, or even in a week... so it's not gonna clear up overnight either... (no matter what the pool stores try to tell you. :rolleyes: )but you know that.

The kit you ordered is the most important pool equipment you'll ever purchase.
The second most important thing you need actually costs you absolutely nothing:
a big ol' dose of P.O.P.P. {Pool Owner Patience and Persistence}​


Good Luck! :flower:
 
Thanks April -

Actually haven't backwashed since Monday, since it's holding steady at 15psi. Just was curious at this "stage" of clearing algae whether it was better to backwash frequently or not, even though pressure is not rising. From you answers above, clearly sounds like I should just leave it alone and watch for stated pressure rise indicating time to backwash. I might give the DE trick a try to see if it helps clear it any faster.

Actually when my filter was up to 25psi, it was nearly choked off. Caught it a few times barely able to run. That's why I was babysitting it all night, trying to let it run 24/7 earlier in the week. When I vacuumed, it would do the same and choke off in less than 5 min's.

Received my K-2006 test kit today. Have some extra R-0870 and R-0871 + a SpeedStir coming tomorrow. I'm sure I'll need extra reagents rather quickly with FC levels this high.

The Aquabot actually has a pretty "fine" filtration bag with a tight weave. It says it filters to 2 microns. It's almost like a flannel sheet on the inner lining and traps very small particles. I always compared it to a filter sock.

Speaking of filter socks - I forgot I have a "Slime Bag" polishing bag that I used once years ago. I'll have to hook that up tomorrow and see if I can get that to help clear the water also. Slime Bag says it filters to 1 micron.

8/18 (Tues):
9:30am: Added gal of 12.5% shock

3:30pm: K-2006 Test Kit Arrived
FC: 23 (test kit results)
CC: 1

8/19 (Wed):
1:00am - added 1/2 gal of 12.5% shock
 

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