And NOw for the Mustard Algae...

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happyheathen

happyheathen

0
Aug 18, 2012
224
Sacramento CA
At what point to you say "forget it" and drain the pool?

I have the unfortunate combination of high CYA (99) and mustard algae (green and yellow) on the south wall at the bottom and spreading.
The south wall is the deep end

Just for giggles:I had Leslie's test the water - they actually printed out OK beside a FC of 1.5 (their target shows 1-4). They use the term "Free Available Chlorine" if that matters.

While I"m here - what is OCLT? I didn't find it in Terms and Abbreviations.

I am seriously considering draining the pool entirely and letting the sun deal with the algae. To get the CYA down to levels which make a Mustard Algae shock affordable, I'd need to drain and replace about 1/2 of the water (yes, I do realize that the shock would best be performed when the water level is lowest).

How long would the pool need to be dry to eliminate the possibility of re-infection?

Opinions? Alternatives? Anyone have a way of "spot treating" mustard algae? From the instructions, it would seem that a spot treatment would simply clear the deck for the free-floating spores to have a nice-clean home.
 
You definitely need to lower your CYA for sure. That's how the mustard algae took hold, the FC is far, far too low and the CYA way too high.

I must ask though, how are you getting a reading of 99 for CYA? It's either 100 or it's not, the test isn't that accurate, but it's better then the pool store and it's as good as it comes for us mere mortals.
Also, how did your CYA get so high? Are you perchance a former puck user and just haven't corrected it since you switched to bleach?

I wouldn't drain the pool just to fix a mustard algae outbreak. I'm no expert on algaeic life forms, but I imagine it'd be hard to kill with no water present, too much bleach mess and too much risk of staining or discoloring, otherwise damaging the plaster. I don't think the sun would do it on it's own, eventually, yes. But would depend on how water dependent the species is as to how long it'd take. The big thing is, who knows where else it may be hiding, either way you'll likely have to shock it when you refill it even if you do let it sit. Just to kill off what's hiding elsewhere, so I really don't see the gain overall. But I'm always open to ideas with things, what the others might have to contribute on the matter.

If you drain the pool by 50%, then don't fill it back up. You'll still have the same PPM of CYA, just less water. It only reduces by dilution, or reverse osmosis.
You really don't have a big enough pool to worry about how much bleach it'll take to kill it off. I mean don't get me wrong, that's a HUGE pool compared to mine, but it's not 35k/40k+ so you shouldn't need a palate of bleach, especially not being a swamp either.

You asked about OCLT, see the shock article link in my signature for more detail. Which you should read and follow all links as well as the mustard algae link in Pool School. In the interim it means "Overnight Chlorine Loss Test". But you don't do that till the end, unless you think it might not be algae, like say pollen. But if it's yellow or brown and on the sides, especially in the shade and not on the bottom. Then it is quite likely mustard.

To kill it, you just follow the standard shocking procedure for algae, as outlined in the articles and what matches your CYA you dilute to. ALso, lower your pH using MA to 7.2 before starting, this makes the CL more effective. Don't even bother testing pH once you start shocking, anything above an FC of 10ppm will give a false pH reading.
When shocking, it is critically important to stay at or slightly above your shock level and not to let it fall.
Once you pass all 3 criteria, clear water/algae is gone off the walls, CCs less than 0.5ppm and OCLT FC loss = to or <1.0ppm. Then you kick it up to mustard shock levels for 24hrs, throw in everything that comes in contact with the pool, including but not limited to; suits, fill hose, vacuum hose, noodles, toys, floaties, inflatable items, brushes, poles, balls, goggles and snorkels. EVERYTHING that ever touches, has touched or will touch pool water!! Then after 24hrs when you pass all 3 criteria once more, you are good to go. Just let FC fall naturally on it's own to proper levels for your CYA and keep on top of the FC, compensating for daily loss from sunlight.

You only hold mustard algae shock levels at the end, not the whole time and only for 24hrs when you finish std shock. So it's not that much more chlorine.

While shocking, you should check in and under ladders, behind light fixtures, skimmers, scuppers, every nook and cranny you can find. Check for algae and it's friends, if you find it, scrub it while you're at shock level and get it clean.

Lastly, you have an TF-100 or other recommended test kit /w FAS-DPD, correct? You'll need this to do your OCLT testing and get your CL levels accurate enough to shock and keep it there.

Do update on your progress and feel free to ask any questions along the way. We're here to help. Oh, and we LOVE LOVE pictures, so post some if you can. There's a tutorial on posting pictures, listed under 'Forum Issues' in the 'Skimmer Basket' section, posted by "moresparkle".
 
happyheathen:

Regarding the mustard algae, I would follow the shock process that y_not described. Draining the pool to resolve this problem is definitely not recommended (see below). The shock process is the answer. Also do not overlook the suggestion to lower pH to 7.2 before beginning the shock process.

happyheathen said:
I am seriously considering draining the pool entirely and letting the sun deal with the algae...How long would the pool need to be dry to eliminate the possibility of re-infection?
Click to expand...
An in-ground pool should not be left dry unless it is absolutely necessary (say for replastering / resurfacing and that is definitely best left to professionals). Even then, it should only be left dry for as short a time as possible. Depending on your water tables, your pool could shift or partially pop up out of the ground if it is left dry too long. I've heard of that happening especially where water tables are high.

Even if your CYA was really off the charts (150-200 or more) which would necessitate a 100% drain or close to it, a simultaneous drain & refill would be the best way to change out the water. You would begin by draining about half the water after which point you would begin filling the pool from the opposite end of the main drain while still draining. This may use a bit more water and may require periodic adjustments to keep the drain & refill rates as close to constant as possible. It will also require you to test the CYA during this process to determine when to stop draining and let the pool refill to its normal level. But that definitely beats a pool shifting out of the ground.
 
I think I remember reading that some testers for CYA only measure to 100, so you might want to dilute with filtered water (not tap with chlorine) and recheck to make sure you aren't at 150 or more before you do a partial drain. I could be remembering wrong about the reading, and you haven't yet said how you came about the reading of 99. What did Leslie's have your CYA AT?
 
You can dilute the pool water with tap water for the CYA test ... there is no CYA in tap water and the possible chlorine level in the tap water does not matter.

If you use 50/50 split of tap and pool water ... double the test reading. Of course this assumes you have one of the recommended test kits.
 
The 99 ppm came from Leslie's analysis

This house was a foreclosure which was vacant for 2.5 years. The pool was dry (rainwater was a nice dark green). After I closed, 2 things happened:
The filter cartridge appeared
Pool was filled - no, they didn't shock the rainwater first, so I moved in with 15000 gallons of algae.

I have since drained it twice. I'm quite accomplished at this point. So no, it will not pop up when empty.

Sacramento does not get freezing, but the water temp is too low for swimming - and will be until May.

The CYA got there because I never had the pump together long enough to fully dissolve the first batch of CYA, so I added more. By the time I got the system operational, there was a load of undissolved CYA everywhere. It finally all got dissolved.

The only test I have is the basic chlorine/Ph titration unit - which is why I'm relying on Leslies' numbers.
 
The best investment you can make will be one of the recommend test kits and then trusting you own tests over the highly suspect pool store testing. This has been proven over and over again in threads here.
 
Take a look at other green swamp threads - you will buy a good kit instantly once you have a clear understanding of what they do for you.


- Sent using Tapatalk
 
Richard320 said:
Overnight Free Chlorine Loss Test
You won't be able to do this unless you have a FAS-DPD test kit.

I wouldn't trust the CYA readings from a pool store.

If it was my pool, I'd order a test kit, drain it, scrub it with bleach, refill it, and then balance it. Shock if still needed. In that order.
Click to expand...

Why drain it? Just wondering what the reasoning behind the recommendation is. That seems like a lot of unnecessary work just to kill off algae, all of that scrubbing and washing. BLEH!!
Why do that when you can just simply drain the high CYA down, then dilute and shock it till clear and you pass all 3 criteria then call it a day.

I agree with the test kit and the pool store numbers though, DUH! :p

Other than that, am I missing something here?
 

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I recovered a foreclosure swamp. No real compelling need to drain all the water when it's easier to clean it up via shocking, filtration and vacuuming to waste (especially if you don't have 16 wheelbarrows full of leaves to dredge out!) The water will carry the chlorine to places you might otherwise not get to. You want to super chlorinate the entire system to eradicate all traces of algae.
Also, not likely great for the system to leave it sitting to dry, because while it ay not ave floated before, hydrogeologic conditions change.
 
I was working on this when Richard added the magic word: Cost.

It would cost me $50 to add enough CaCl to stop the peeling of the little remaining plaster (at $4000, a re-plaster is not going to happen).
With the test kit and bleach, we're close to $200 to keep water to which I have absolutely no sentimental attachment.
The spa currently contains a small colony of mosquito eating fish - that is how devoted I am to this time and money pit.

My lower back looks like a question mark on the X-rays - scrubbing a pool weekly is not on my priority list. I have a tenant who is eager to have a pool, but not so much that he will lift a finger to maintain it. Pool guys are out ($).

The pool is plumbed and equipped to to support a pressure cleaner. I'm leaning strongly to leaving the thing dry (or green) until I have a cleaner to do however much it could.
Right now, I have a replacement filter in the garage and almost enough plumbing to connect it (mis-counted inventory). I will need the water to test its install.

As to fill and drain: I cannot use the pool pump to drain - I have a junk pump I use. Its GPM is much higher than the filler can match. To approximate simultaneous fill and drain would involve draining X amount, filling by X amount. By the time I get to the 1/2 mark, I'd be pumping out the water I had just added.

The pool calculator says to drain 60% of the water to correct CYA - I'm not adding the CaCl just to throw 60% of it away.
So we're discussing, at most, draining the remaining 40% as well.

Oh - I can't swim - so diving to the bottom of the deep end to scrub off the algae is not an option either

Has anyone ever had a re-occurrence of mustard or any algae after 5 mos of sunshine on a dry pool?

I've never seen green algae anywhere dry, and this site was the first time I'd heard of "mustard algae" - smells like these are water-dependent specie.
 
Swampwoman said:
I recovered a foreclosure swamp. No real compelling need to drain all the water when it's easier to clean it up via shocking, filtration and vacuuming to waste ...
Click to expand...

Um....
Maybe for you - for me, it takes less time and effort to drain the last 40% than it would to scrub walls, vacuum, test, partial drain, test, shock, shock some more, test again and again the next day.

I can re-position the junk pump once or twice more to get the last of the contaminated water much quicker and easier than that rigamarole. See previous post re why scrub and vacuum are not things I love.
 
^yes, I agree. When I posted, I wasn't thinking about you cya and required drain already. In my case, I had zero cya because it had all been converted to ammonia from stagnation, and I had compelling hydrogeological reasons not to drain, plus a liner.
 
Actually, when we started, we had no idea there were so many leaves there because when we bought the house there was a winter safety cover secured. When it was inspected, we knew it was black and stagnant, but were more focused on running power to test the equipment because all the conduit in the pool house had been cut (literally, every single line) when vandalized.

Then, we were assured it could be cleaned up with a little shock n floc by the pool co. and that considering the hill, the sump, the river etc. there was a chance of structural damage as well if we used a trash pump instead and couldn't fill fast enough (at the point, couldn't use truck water to refill because no one knew what kind of cleanup might be required first and ya can't leave a trck sitting for days.) At the time we were also uncertain about whether the iron laden well might run dry because while legal, no one could find the records or depth. The pool co. started the project, but were making no progress whatsoever so after two weeks of that nonsense and a running tab on labor, I started surfing the web and found pool school. At that point, we still couldn't see and had no idea what might be in there. So I decided to shock it in order to SEE what was down there.
Which turned out to be more leaves. Etc. (and a cell phone battery and a broken leaf rake and a full bottle of floc...which kind of painted a sad picture about what life was like for the guy who foreclosed at the time...)

So it was the liner plus a lot of unknowns and a desire to avoid having to budget for possible reconstruction while addressing myriad other projects to rehab the house.

I was just happy we didn't find dead bodies ;)
 
Update - It makes NO Sense, but...

When I decided I'd just drain the thing for the winter, I figured "what the heck" and dumped the remaining polyquat (almost a full quart) directly over the primary infestation of the green-and-yellow algae. Since then, I have used only the natural thermal-induced currents in the pool - no pump, no filter.

The stuff was gone within 48 hours. I dumped a few cups of 6% bleach (another "why not?" proposition).

Otherwise the pool has just sat unused. After 3 weeks, it is still clear of any trace of any algae.

Did I luck out or can I still expect re-infestation come May?
 
If it's green algae, you probably killed it all and can keep it away with normal chlorine levels. If there is yellow/mustard algae, it prefers shade so could still be hanging out behind light niches, under removable ladders, inside poles used for cleaning (brushes, nets, etc.). It needs to be blasted with rather high chlorine levels to kill it off. Otherwise, it can come back at normal chlorine levels though can be kept away with an FC that is 15% of the CYA level, but that can become impractical and cost more since it's more than double the usual daily chlorine loss at that level.
 
Not to mention that Leslie's (yea, but they're the only numbers I have) show CYA of 99

The only place which was affected was the only side (south) which does not get bright sun during the day.

If my health recovers, I'll just drain it a see what May brings
 

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