Yellow Algae??? went away for a week and.....

[Brick81]

Good day,
Just a quick question, is this yellow algae??? Before we left on our vacation noticed what appeared to be yellow lines/stains in the corner of the deep end (first picture). It would brush away quite easily.

Came back from a week away to this very cloudy/yellowish pool. Now before I left thought the salt cell may not producing like it once was (it’s been 3 years). So things I’ve done since I’ve been back is clean out the salt cell (looked good to me), started putting in some liquid chlorine, and some muratic acid and running our robot. Also got pump running 24/7. We have been having quite the hot spell here to so I’m sure that hasn’t helped. Got neighbors telling me to use algaecide/clarifiers ect, but if I've learned anything from this site it's to keep it simple!!!

Numbers from last night:
3.5 fc
8+ PH
TA 90
Calcium Hardness: 120
CYA: Ran out of the Dang stuff, picking up more today, was around 50/60 when I last checked

Numbers this morning:
10 fc
7.6/7.8 PH

Also I’ve got the hair net in the skimmer basket trick going on, if it is indeed algae should I be cleaning the cartridge filters too (just put a new set in this year) or would the hair net catch a lot of that???

We’ve never had to do a SLAM before, but figure that might be what’s needed.

Thanks again!!

 

[Acuity]

I'm by no means a pro here (I'm dealing with issues myself), but I see your post here going without a response so I thought I might chime in based on my experience with pools. You're missing some key criteria here, namely CC and CYA. Having an accurate and up to date CYA number is important so you know what your FC needs to be to kill off your algae problem. Follow this to see what your FC should be for your given CYA level:

PoolMath

Discover the calculator behind the perfect pool, PoolMath. Dealing with pools has allowed TFP to become the original authors of the best calculator on the net.

www.troublefreepool.com

Mustard algae is a difficult thing to get rid of, and does tend to come back. To kill mustard algae you want SLAM and you can't do too much brushing, and then when things seem under control you want to do the extra high (mustard algae on that page) shock level for an additional 24 hours to make sure it's really dead. Brush everywhere, several time, and then even more. Get everywhere the algae can hide. Wash any items with a diluted bleach that have been in the pool. Even if you remove these items from the pool for a short period, mustard algae can survive outside the water.

Something else of note is that your pH level looks high. Chlorine functions better at a lower pH so I'd try to bring it down from 7.8 to 7.2 — some might say this is okay though, but I like to keep mine at the 7.2 level if I can (my pH tends to run low). It's important to note that once you start the SLAM process your pH will artificially appear high. Your chlorine is already on the high end, but I think your pH level is accurate until around 12 PPM FC (hopefully one of the pros can chime in on this one).

Edit: Your filter should be cleaned when it's 25% higher than your starting pressure. I keep a second filter on hand so that one can be in use while the other is being cleaned.

Good luck!

 

[frogabog]

Mustard algae likes to hide in the shadows, your algae bloom looks kinda normal. But you never know... it could be mustard. But I'm guessing it's just algae.

You definitely need to SLAM though. It sounds like you have the smaller kit (K-2000 vs K-2000c) if you ran out of CYA reagent. You will need more R-0871 and DPD powder (R-0870) for SLAM. I'd suggest getting that on order now. TFTestkits has the best deal and quantities. Look for the XL Option in the Refills section. It's both reagents as one "item" and can be purchased separately from the kit. It's also $.25 cheaper than buying them individually which isn't a massive discount, but it's still a discount.

 

[Brick81]

Ok so got my replacement regents from our local distributor (they are the rep for Ontario, luckily are in same town as I work in Newmarket,On). CYA ended up only being around 20-30.

Dumped around 5L of chlorine into the pool and some more Muratic acid and turned off my SWG, still didn't look better after the first night. Wife was starting to say, call the pool guy to which I replied "give me 3 days".
Any way took reading at 8pm:
19.5 FC 7.4PH
Woke up this morning
16.5FC and 7.6PH

Dumped in some more chlorine and a little bit more Muratic acid. Kept pump running and SWG still turned of. Looks like today is an overcast day to, so that should help I'd think. Anyway wasn't sure if was going to work (had to resist the "quick fix" solution) but looks like slow and steady seems to be working as it looks like progress is being made.

I'll consider this case closed (although I know it's not over yet) but will post an update once it's all completed.

Thanks again for the comments/guidance!!!

 

[Brick81]

Final picture (day 3), did the OLCT test and held steady last night, Just got cloudy water now but would assume that will clear up over time. Still haven't cleaned my cartridge filters however...

Checked the FC this morning and was still 19.5 ---- Now kids want to go swimming today, may still be a bit high for that however!!!

 

[frogabog]

So, you passed 1 of the 3 criteria. You haven't reported on CC, but one of the criteria still remains. Water is not clear. You will need to keep your SLAM level FC maintained while that clears out. Filtering is your friend in this case.

If you can see the bottom of the pool and your FC level is at or below SLAM level, it is safe to let the kids swim. But so maintain FC at SLAM level till you get the water clear. If you skip or skrimp on this part, you may be SLAMming again next week.

 

[AimeeH]

Just wanted to throw it out there that the PH test can be inaccurate with FC above 10 so don't bother testing until your FC comes back down. Save your reagents

 

[Culleebo]

In reference to the picture OP uploaded of their clear water with green streak on the bottom:
Is it normal/acceptable to have those streaks of algae on the bottom when the water is crystal clear? Is it dead algae that just needs to be brushed and filtered out or does it indicate a bloom and the need for a SLAM?

 

[Brick81]

I had never had those "streaks" before, didn't think much of it to tell you the truth. They were just in the corners of the deep end, one on each side. Now I know what to do if I seem them again!!!!