Yellow Out Swimming Pool Chlorine Shock Enhancing Treatment - 2 lbs.

iving in Texas, I deal with stubborn dark yellow algae on my pool walls every single year. It doesn't seem to matter how much work I put into keeping the pH and chlorine levels exactly right—the yellow spots always find a way back. This Yellow Out treatment is the only thing that actually works for me. When you follow the shock process described on the bottle, it cleans everything up completely. The best part is that I barely have to brush the walls at all; the chemicals do the heavy lifting, and the pool looks back to new in no time. If you’re tired of fighting mustard algae that won't go away with regular chlorine, this is definitely the solution.

A few weeks back, I walked out to check the pool and was met with a cloudy, yellowish mess. With family coming over for a Saturday cookout, I needed a quick fix. I picked up Yellow Out, followed the directions, and added it to the pool one evening. By the next day, the difference was incredible. The water was clearer, brighter, and the unpleasant smell was gone. When the weekend rolled around, the kids were cannonballing into sparkling blue water like nothing had happened. What impressed me most is how fast it worked and how little hassle it was — no long waits, no extra complicated steps. It turned what could have been a ruined pool party into a fun, worry-free afternoon.

I can't even begin to put in words how well this worked on my inground pool. We have been fighting very aggressive green algae, and algae stains, all season to the point where the shallow end and much of the sides had ongoing algae or algae stains. I used the Clorox algaecide & clarifier several times. It helped for a day or two but it never really got rid of the algae, and especially the stains. Honestly, I had all but given up when I read the reviews on Yellow Out. Per instructions, I vacuumed the entire pool with a vacuum brush (no wheels), the next day I swept it and added 4 lbs of Yellow Out to my 33,000 pool and the next day I shocked it with chlorine. It has been five days now. THERE IS ABSOLUTELY NO TRACE OF ALGAE, OR ALGAE STAINS IN OUR POOL ANYMORE! Simply amazing.

Works great but only when I used twice the amount.

I honestly am shocked by how awesome this product is at removing algae quickly. I've gone to war with mustard algae for weeks at a time before trying this product. It literally works in 12 hours to completely remove the yellow. You do need to brush down everything first so that it can work properly and you will hear a snap, crackle and pop sound in your pool water while it is working. I do experience a weird phenomenon after using this product where the chlorine level drops to zero after 2 shocks in 24 hours. I'm sure this has something to do with the chemical reaction that is taking place from the Yellow Out. Normally 2 shocks will set the chlorine off the charts. I've used it for 2 different blooms, 2 years in a row after a heatwave. I have a pop-up steel frame with vinyl liner pool, and it gets really warm after heat waves, making algae a constant problem. Not sure why it doesn't work for some people, but it may be the PH level or too much chlorine when starting. Follow the instructions and it should be fine.

This was purchased as a remedy for yellow-mustard algae in my fish and plant-free water-fall pond/water feature. The label isn't specific on how it works but after a little research, I found that it's imperative that you follow the water chemistry relative to pH for it to work at its best. I inadvertently over-estimated my actual water volume of 450 gallons to be 800 gallons but dosed it at 1000 gallons. (a desired 25% increase I always add when using an oxidizer/sanitizer disinfectant type chemical). Thankfully, there was no obvious (immediate?) damage to the pump or piping. I don't recommend others to purposefully overdose by this >100% mistake. Despite the high dose (unknown at the time), I also followed up with the instructed amount of chlorine. I applied everything after sunset and brushed down all accessible rock surfaces immediately after adding the chlorine portion, simulating the actions one would take with a swimming pool. Chlorine was dosed as instructed during the day intervals as well. The chlorine used a CYA build-up of around 50 ppm for longevity purposes against UV breakdown. The treatment was repeated the second night, using the same or even slightly higher dose (remember, I wasn't aware at the time that I was significantly overdosing) with chlorine follow-up. There were no measurable differences in the sand-like streaks of algae spores (?) that tend to settle on the top pond overflow edge. Usually, I add the chemicals to the lower pond for mixing and distribution purposes. I've tried adding the product just on the sand streaks at the top pond and then adding the chlorine 5 minutes later. It would "react" with foaming action like an acid was eating something, but in the long run, it was merely a show of intent without actual results. If this product fails to work at essentially double the dose, how can you expect it work at half that much - a standard dose? Granted, this isn't a swimming pool with level, curved walls and bottoms but even a pool wall and floor is porous. It just doesn't have the large rock/boulder gaps, creases or pockmark craters below the waterline, or multiple liners that can trap debris. Still, a yellow mustard algae remedy is either a remedy or it isn't. If you don't see the result promised after following directions, it's time to move to plan B, C,...

Most important thing to know is that it works for our pool while chlorine alone did not.

Too expensive. Didn't work.