losing chlorine, algae in solar panels?

[shannon]

Greetings,

I am having problems with chlorine loss. Last year I had no problem with swg keeping up chlorine levels. This winter I did a partial drain for winterization. Upon opening three weeks ago, I noticed some brownish powdery substance on pool bottom along with some leaves and stuff as well as some green algae, especially along water line. After filling, brushing and vacuuming I used a couple bags of "shock" and mustard algae killer and phosphree. Pool became crystal clear in a couple of days but I had no chlorine even while superchlorinating with swg. I have been using the local pool store as well as test strips (tf kit should be here today!)to determine I had cya=30. I added cya and strips show close to 100. I will have more accurate data soon. I shocked with a couple of with pool stores powders but I think maybe it was insufficient, so four days ago I added six jugs (96oz) of 6%bleach in the early afternoon followed by six more in the early evening. Chlorine was all gone by yesterday afternoon. Tested stream from swg and it is producing chlorine, salt is good(3200) volts 26 amps 5. Used pool calculator to determine I needed a higher dose of shocking. Added 9 (182oz) bottles of bleach last night(real nice color on test strip!). I tested today for ammonia and the walmart fish kit says .25 ppm or less, but not zero. My chlorine level this morning is still very high.
How long should I keep it this high, is this an algae (still have some brownish powdery stuff) ammonia or a bromine problem because of mustard algae killer. Any one have problem with algae growing in solar panels? I will be adding borates as soon as I get this under control.

thanks

 

[frustratedpoolmom]

I can't wait till you get your test kit. The strips are notoriously innaccurate.

Don't bother using the "superchlorinate" on the SWG- it just shortens the life of the cell. Supplement with liquid chlorine as you have been doing, that is faster and more efficient.

If your chlorine is dissappearing that fast, something is consuming it. If your CYA is that high, it's not sunlight, so it must be organic. You need to keep adding chlorine frequently until it holds at shock level, overnight.

Are your solar panels on bypass, or does the chlorinated water regularly flow thru them now? That should kill any algae growing in them. What is your FC level, actually can you post a full set of results?

FC
CC
TA
PH
CH
CYA

More knowledgeable gurus regarding the ammonia issue will be along shortly to chime in I'm sure. Hang in there, POP! More POP!

Pool Owner Patience

 

[shannon]

Thanks for the reply, yes the swg has been off for a couple of days. I have manual solar valves and they have been on since pool startup. My strips and ndicated yesterday before adding 9 gal chlorine:
ch 210 (previous pool store number as well)
cc 1
fc 1
ph 7.5
ta 150
cya 90
all these are heavy on the ish.
after 9 gals bleach::
cc off scale
fc off scale
ph 8.0
cya 100
since it appears ph went up and I need to lower ta for borax addition, I added 1qt. muriatic acid last night, it appears that this morning
ta 120
ph 7.5
running pump 24/7
of course all these numbers really are just a test of my colorblindness., waiting on the mail...

 

[JasonLion]

It is fairly common to have some ammonia, or other organics, in the pool at the start of the season. This can come from the breakdown of CYA over the winter, from algae, from organic debris getting into the pool, or from fertilizer getting into the pool. The solution is to keep adding chlorine until it burns off the ammonia/organics.

Keep in mind that you shouldn't trust the PH reading when the FC level is very high. If the FC is over 10 the PH reading is a little questionable, and if the FC level is over 20 you should completely ignore the PH reading.

If your CYA level is 90, your FC shock level is around 25. You want to keep bringing the FC level up to 25 until the FC level remains steady overnight.

 

[shannon]

Thanks, I did the mustard algae shock according to the calculator. My chlorine should have been near 50 last night. My test kit arrived at my post office this morning, I should get it in a couple of hours. Can't wait to see how accurate the test strips/my eyeballs, and the pool store here is. My test strip still shows same color, way in excess of 10 ppm fc and tc. The "mustard algae" appears to be reappearing on the bottom of the pool. I have been scrubbing thoroughly (walls, floor, steps, light) every day. The pool has been crystal clear since the second day of opening about 3 weeks ago...

shannon

 

[shannon]

Test kit has arrived!

here are the numbers

fc 40
cc 0
ta 140
cya 90
ph 7.2
ch 270

I will test fc after dark and then in the morning. It may be a little lower than 40, I didn't stir the last few drops and I did see a clear spot forming at about 75 drops, it may have cleared if it had been swirled.

 

[frustratedpoolmom]

Okay, then we'll wait until morning. If the 40 holds overnight, and the "mustard algae" is still present, it's possibly just dust or pollen that your filter didn't get. If that's the case you could try skimmer socks.

 

[shannon]

chlorine update at 8:00pm central time

fc 22.5

previous fc at about 3:00 pm possibly off due to not swirling with every few drops and the sun probably lowered it as well. whats the normal fc drop per day in full sun with cya 90?

will check again in morning

 

[shannon]

I checked the chlorine at 0630 am. It held at 22.5. The vast majority of the brown powdery substance has not reappeared. I have previously vacuumed it to waste being careful to not let any poof away. It always comes back within a day or so.

So, now what? Do I let the fc drop to about 4 and see if the swg can keep up normally or is my daytime fc drop still too high? According to the calculator I should have had 50 ppm fc sunday afternoon at about 330 pm. One day plus about 4 hours of sun for at least a 25 ppm fc drop seem high but I suppose one would have to subtract the unknown quantity that was consumed by algae sunday night.

thanks

shannon

 

[frustratedpoolmom]

Morning! That's a good sign.... do you cover your pool? Mustard algae tends to grow on the walls too, especially on the shady sections. There is a possibility that it isn't mustard algae at all. You could keep the FC up to shock level for a couple more days and If it reappears there's a good chance it isn't algae.

There were several threads last year that described your situation and it remained unclear what the cause was - dust, pollen, etc., because FC tended not to drop. Some were able to examine the substance under a microscope and determined in their cases it was pollen. You can do a search for Mustard Algae and read some of these threads.

You can try skimmer socks, see if that helps? If you don't cover your pool, try that, because that can cut down on dirt/dust, if that is the substance.... Have you looked inside your filter, to make sure the sand isn't channelled, and that this "stuff" is recirculating into the pool (I see you said you vacumed to waste....hmmm).

Is it possible for you to post a pic of the mystery substance if it returns? I'd keep that FC another day and see what happens....

 

[JasonLion]

It is the start of pollen season, getting fine organic "dust" in your pool is not at all uncommon. It is often difficult to distinguish mustard algae from pollen. The simplest way to tell them apart is that mustard algae will almost always start growing on the walls on the shady side of the pool, while pollen usually settles in all the slightly lower spots on the floor, and generally anywhere the circulation slows down. Another way to tell is that mustard algae will disappear completely when you hold the pool at shock level, only to reappear when the chlorine level comes down, while pollen shows up every day and tends to be most plentiful when it is windy.

My assumption is that the chlorine got used up fighting the last of whatever was in your pool to start with, and things should now be fine. If I am right, you will only lose a little chlorine today, 10-20%, because of your high CYA level.

 

[shannon]

Hmm, it has been very windy the last couple of weeks. I will keep checking my fc level today and also put my solar cover back on, I am sure it has pollen all over it. I took it off to superchlorinate but just in case it has any algae on it I will keep fc level up for another day. I just got the cover in the mail about a week and a half ago and it was only put on after all the green was gone. I should also clean all the toys and tools as well. My old cover only lasted 1.5 yrs. It was the diamond pattern one. Luckily it was under warranty and the company said the diamond bubble pattern ones always came back before warranty was up. I upgraded to a round bubble 16 mil clear cover.

Unfortunately my camera is mia, but it really doesn't go up the walls. The brown stuff only seems to like the floor and the slope to the deep. I did have the selector valve off of the filter a couple months back and the sand looked normal, no channeling.

 

[frustratedpoolmom]

I've left my solar cover on when I shock my pool before I go on vacation, no ill effects. It's probably a good idea to leave it on if it was on when algae was present, JIC. Sounds like you're getting a handle on this

Let us know how its going.

 

[gtm]

There were several threads last year that described your situation and it remained unclear what the cause was - dust, pollen, etc., because FC tended not to drop. Some were able to examine the substance under a microscope and determined in their cases it was pollen. You can do a search for Mustard Algae and read some of these threads.

Shannon, if you do decide that it's pollen or dust, the threads last year that poolmom refers to might be very helpful. I was having problems last year that sound very similar to yours, and I finally decided the "poofy" stuff was indeed very fine dust or pollen. In those discussions you'll find reference to the trick of adding a little DE powder to help your sand filter to trap finer things. I did this and it helped a lot. Much less on the bottom of the pool, and it took much longer to accumulate, I think because it wasn't just blowing right through the filter. Also, I thought my water was pretty clear before, but after doing this I noticed a definite improvement on that front, too.

Good luck!

Cheers, Gary

 

[shannon]

It has been overcast with occasional light showers here today. I did put the solar cover on this morning. I turned the swg on to 80% about 9am to see if I could hold my fc level at the 22.5 that I had this morning. I just checked the fc at 2:30pm, and it shows 18.5. I'll turn the swg back off and add more bleach to bring it back to shock level. That's a 4ppm drop in about 8 hours of heavy overcast daylight with 4.8 hrs of swg production.
Is that normal or possibly algae on the cover? I'll do the overnight test again with the cover on.

thanks

 

[shannon]

Well I checked the fc a little late this morning at 0730 instead of 0630. I found a .5 ppm drop over last nights level. The pool doesn't get any direct sun until after about 0830. I'll watch fc levels over the next couple of days and then bring swg online while I continue to aerate in preparation for adding borax.

Anybody ever turn their return on their aquagenie upside down for aeration? I put a sump pump on the steps and it shoots a fair amount of water about 2 feet high. ph up about .2 in under 24 hrs.

thanks
shannon

 

[frustratedpoolmom]

I would suspect that the prior day's drop was mostly caused by something on the cover that consumed the chlorine.

Also, was the SWG off during the night? It has to be off in order to do the overnight test. That's the only way to know for sure if there was a drop or not.

 

[shannon]

Yes the swg was off overnight, so the test was good. I inverted the return on my aquagenie and it does bring a lot of water up above the surface but doesn't clean the pool very well. I have the swg on for today just to help with aeration.

shannon

 

[shannon]

After days of aerating and adding muriatic acid, I finally got my ta down to 80. It seems the lower the ta got, the rate of change of ph and ta decreased. I was going for ta of 70 but it seemed that would take much longer(maybe I was just getting impatient).

I just added the borax (11 boxes) and 3.25 gals of muriatic acid. The ph before was about 7.4 and is now 7.7. The ta went up from 80 to 100. Does this look about right? Should I leave the ta alone or try to adjust it down?

It looks like my swg now has no problem keeping the chlorine level up, must have worked thru whatever problem (algae etc.) that I may have had. Thanks for your expertise!

shannon

 

[frustratedpoolmom]

Hi Shannon,

I would repeat the Lowering TA procedure. With an SWG you will likely see the PH continue to creep up, so it's better to lower the TA now, say 70-80. Do a search on the forum and read the threads about lowering TA, there may be some hints in there from others who have experienced it.