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.

We have had such a problem with yellow bloom. Tried everything but it took over our pool. We tried this once and the next day we had a clear pool. We keep one handy, just in case. But it really works. Highly recommend.

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.

Works great but only when I used twice the amount.

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.

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,...

Didn’t work nearly as well as the “hype” from pool company sites led me to believe it would. Maybe it was a “me thing”?, but I don’t think so… I have no problems following instructions. Overall?, this was a waste of money…

This product is incredible !!!! We were trying to shock and clean a pool for WEEKS with NO success. We went to local pool store every other day testing water and adjusting pH, cya, chlorine, you name it ! Even partially drained a pool to replace half of the water ! I do not even know how much money was spent on alllll kinds of chemicals, tests, water , electricity, scrubbing - HORROR story !!! Than by accident I saw this product recommended on one site after hours and hours of reading about pool problems and was thinking - right, yeah, this $20 "unheard of" powder will help *eye-roll BUT I was desperate and ordered it on Amazon. We sprinkled it in water at sunset and next morning we woke up to Caribbean blue pool O_O !!! We were in state of awe lol and were going to the window every 10 min to see it over and over again because we just could not believe it ! It was not THIS turquoise blue EVER, and we own this house for almost 8 years ! And from swamp green to this clear blue !!! MIRACLE powder- I do not know what else to call it ?!

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

Too expensive. Didn't work.