Fighting Mustard Algae yet again, am I on the right track?

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I shock and swim the next day. :mrgreen: Haven't melted yet... but I haven't had to shock yet this year. :mrgreen:
 
At the levels of shocking we recommend on this forum (around an FC level that is 40% of the CYA level), this is roughly equivalent to a pool with 0.6 ppm FC and no CYA. So this is less than found in most indoor pools. It's more than you'd want long-term (and my wife is annoyed every winter season she has to replace her swimsuits due to swimming in a community center indoor pool during the winter with 1-2 ppm FC and no CYA), but it won't hurt you. You shouldn't drink lots of the water, but you wouldn't do that anyway.
 
Update:
I last worked on the pool on 5/15, it is now 5/26. It has rained for the last 3 days. The pool is clear but has debris (mustard algae?) in the corners and the wrinkles of the liner (the usual places that it shows up). I had turned the SWG off while the FC was at Mustard Algae shock levels and forgot to turn it back on until today. I now have it in "72 hr BOOST" mode. I sampled this morning and got these results :rant: ...

FC - .5
CC - .5
TC - 1.0
CYA - 50
pH - 8.2+
TA - 240 (built an aerator and it's been running for the last 10 days :scratch: )

I'm gonna go vac to waste (water level is high from the rain anyway) and add some CYA afterward. I hope that the SWG is working properly now that I reprogrammed it. We'll see.

Add in to this ridiculous scenario that we're leaving for the Dominican Republic on Saturday for a week and I don't want to come back to a swamp (again).

Have I mentioned that I hate this pool? :grrrr:

EDIT: I tested my water straight from the tap and the TA is 330! No wonder I can't get it down!
 
A couple of questions:

1. When testing for TA is the test completed when the solution turns red and stays red? It "flashes" to red a good bit earlier but won't stay red.

2. Algae (from my reading) thrives when circulation is inadequate. I'm wondering if my pool has a large enough pump and/or enough returns to achieve adequate water movement. The pump is 1hp and there are 3 returns (4 if you count the port for the Polaris). Because it's L-Shaped there are some significant "dead zones".
 
The test is complete when it stays red. The flashes are normal and as you swirl they go away. It's when it changes to red and doesn't fade away that you are done, but you verify this by adding another drop and seeing that it doesn't change (i.e. go from a gray-red to a real red). This link may be helpful.

Poor circulation will allow the chlorine level to drop locally if algae gets started and that can lead to runaway algae growth. You can compensate for this with a higher FC level relative to CYA. For mustard/yellow algae, an FC that is at least 15% of the CYA level usually works. Though it's better to completely get rid of the algae through shocking, it can be difficult if algae persists behind light niches or on equipment (poles, etc.).

You might consider using 50 ppm Borates to at least take the edge off of the algae growth. At least this one-time application doesn't have the side-effects of a copper-based algaecide nor the weekly requirements of PolyQuat 60 or a phosphate remover. Also, the Borates will help to slow down the pH rise, though you still may have to add a lot of acid given the high TA of your fill water.

If you were to use a pool cover, then that would cut down on the evaporation and refill which increases the TA and leads to such strongly rising pH. It would also cut down on the carbon dioxide outgassing that directly raises the pH over time. Obviously, you need to add acid to lower the pH right now. As for your trip, you could either 1) shock with chlorinating liquid or bleach and then have the SWG set to more of a lower maintenance level or 2) add a PolyQuat 60 algaecide assuming you don't have time to do the 50 ppm Borates before you leave.

Richard
 

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SinistrV6 said:
Update:
I last worked on the pool on 5/15, it is now 5/26. It has rained for the last 3 days. The pool is clear but has debris (mustard algae?) in the corners and the wrinkles of the liner (the usual places that it shows up). I had turned the SWG off while the FC was at Mustard Algae shock levels and forgot to turn it back on until today. I now have it in "72 hr BOOST" mode. I sampled this morning and got these results :rant: ...

FC - .5
CC - .5
TC - 1.0
CYA - 50
pH - 8.2+
TA - 240 (built an aerator and it's been running for the last 10 days :scratch: )
I'm gonna go vac to waste (water level is high from the rain anyway) and add some CYA afterward. I hope that the SWG is working properly now that I reprogrammed it. We'll see.

Add in to this ridiculous scenario that we're leaving for the Dominican Republic on Saturday for a week and I don't want to come back to a swamp (again).

Have I mentioned that I hate this pool? :grrrr:

EDIT: I tested my water straight from the tap and the TA is 330! No wonder I can't get it down!
Click to expand...

A) You should "boost" your chlorine level with liquid chlorine. Using the SWG like that will shorten the life of the cell.

B) Acid Lowers TA. Aeration raises PH. IF you are trying to lower TA, you MUST use a combination of Acid AND aeration, repeating the process until the PH AND TA are where you want them. Aerating the pool and walking away for 2 weeks is why your PH is so high and your TA didn't move. Read the complete instructions for lowering TA in Pool School.

SinistrV6 said:
A couple of questions:

1. When testing for TA is the test completed when the solution turns red and stays red? It "flashes" to red a good bit earlier but won't stay red.

2. Algae (from my reading) thrives when circulation is inadequate. I'm wondering if my pool has a large enough pump and/or enough returns to achieve adequate water movement. The pump is 1hp and there are 3 returns (4 if you count the port for the Polaris). Because it's L-Shaped there are some significant "dead zones".
Click to expand...

1. When doing the TA test, be sure to wipe the tip of the dropper bottle with a damp cloth, in between drops. This will cut down on static which reportedly has caused inconsistent drops to form and thereby innacurate TA test results. So give that a try and see if that makes a difference. If the water never stayed red, you didn't complete the test.

2. Algae thrives when chlorine levels are allowed to drop that low. Your CYA is too low for an SWG, it should be 70-80. If you keep the pump/filter running for longer periods, especially during the daylight you should be fine. IT's always a good idea to brush the pool daily. We never brush our pools enough. Properly balanced, adequate chlorine levels and daytime circulation and you shouldn't get dead zones. Your pump is fine, just make sure you are running it enough, especially during the day.

Richards advice for your vacation is a good one. The polyquat will consume some of the chlorine, so be sure to add the PQ60 24-36 hrs before you leave and then the night before you go shock the pool with bleach and set the SWG to a low maintenance level.
 
I was short on Bleach the other night so I added the 1.42 gallons I had on hand and about 30 oz (by volume) of some Cal-Hypo that I had here. Also added about 4# of CYA.

Here were my results tonight (48 hrs later)

FC-4.5
CYA-80
pH - about 8.0

I plan to shock it to a higher level in the AM before we leave and hope the SWG can take care of the rest while we're gone. I'll update when I get back. Thanks for all of your help to this point.

BTW, I have 4 neighbors who all have vinyl IG pools w/SWGs. Obviously, they use the same fill water that I do. I'm gonna sample one of their pools when I get back and see what their water "looks" like. They do almost NOTHING to their pools year round. My one buddy says he "throws about 4 of those 1# bags of shock in it when he first opens it and never touches it again!
 
SinistrV6 said:
BTW, I have 4 neighbors who all have vinyl IG pools w/SWGs. Obviously, they use the same fill water that I do. I'm gonna sample one of their pools when I get back and see what their water "looks" like. They do almost NOTHING to their pools year round. My one buddy says he "throws about 4 of those 1# bags of shock in it when he first opens it and never touches it again!
Click to expand...
SWG pools are low maintenance due to the automatic generation of chlorine, but I doubt they do nothing to the pool since most SWG pools will rise in pH over time. If they don't add acid, then their pH can get pretty high. If they had plaster pools, they'd probably have scaling, but because they have vinyl pools with lower Calcium Hardness (CH) all they have is high pH. That's not great on the eyes.
 
Well we're back from the D.R. and I returned to a pool that is crystal clear BUT has a considerable Mustard Algae growth!!!! :grrrr:

I added 1.5 gallons of acid before I left to try and lower the pH. Don't know what happened to it because the pH is still high.
Here were my results last night when we returned...
FC-1.5
pH- 8.2
CYA- 65
TA - 190 (This is less a chemical change than a change in testing method I think. I wiped the tip of the bottle between each drop and got a signicantly lower reading)

The SWG was "OFF" due to "LOW FLOW" when we returned. How long it had been off is anyone's guess since we were gone for 7 days. I cleaned all the strainers and the strainer before the cell and the cell itself and restarted the pump. The SWG came on normally, then I put it into "24 HOUR BOOST" mode just to see if there would be any change by this morning. There was a small change.

This morning the FC is at 2.5 with a trace of CC (.5 or less)

I took some pics of the algae and a short video of me "disturbing" it on the steps so you could see how it behaves if anyone is interested.

Sooo...looks like I'm back to shocking at Mustard Algae levels again. I gotta be destroying this liner...


BTW, its very clear in the pictures that I took where there is circulation and where there isn't. The area directly in front of the eyeball in the "L" is crystal clear. Algae all around it...
 
can you send it to video.google.com ? also, the recommendation around here is not to use superchlorinate with the swg because it's too slow and kills the cell faster. I hope you've added acid also, or plan on doing it real soon.
 

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