Great product came leaking thoughI have 20 solar panels that were bought in 1999. If they ever had something like this applied to them it wore off years ago.I cleaned the panels and then I used a hand spray bottle to apply the diluted solution to the wet panels as instructed. I chose to allow the panels to simply dry instead of using a squeegee to dry the panels. I noticed that the surface tension of the water on the panels changed immediately. It was obvious that the water was spreading out, leveling itself. After the panels completely dried they were darker, blacker and they appeared somewhat shinier. Difficult to explain.It was August 2021 in California. The forest fires north of Stockton creates a lot fine of ash that falls on the panels. This ash covers the panels every night and after each week I rinse them off to insure the best possible production.Before applying Glass Gleam the ash would form a sort of mud that required scrubbing to loosen and rinse away and then using a squeegee to dry the panels.After applying Glass Gleam a simple rinse is all that is required. Water runs off of the panels very efficiently carrying most of the ash away with it, at least 90%. I believe that the need to physically clean these panels will be reduced by at least 75%.At the time of this writing 1 quart makes 100 gallons of solution and costs $32.00 (Ouch!) 1 gallon costs $48.00 (what??) and it makes 500 gallons! I now have a lifetime supply. (Not too expensive after all).My 1 quart hand held spray bottle is still 3/4 full after applying the solution to those 20 solar panels.I DO recommend Glass Gleam to anyone that wants to make it easier to clean their solar panels.I HAVE A LARGE SOLAR UNIT. I PARK MY 9 FT TALL VANS UNDER IT. SO ITS NOT EASY FOR 68 YR OLD TO CLEAN.SO I HOOKED UP A SPRINKLER SYSTEM WITH AN IN-LINE SOAP INJECTOR TO MIX SOLAR CLEANER WITH WATER GOING TO SPRINKLERS. WORKS GREAT! FIRST DAY IT WENT FROM MAKING 7.5 KW TO 11KW.NOW WE'RE MAKING ELECTRICITY LIKE IT'S SUPPOSED TO. WILL BE BUYING AGAIN AND AGAIN!!! YOU CAN SPEND $35.00 - $50.00 FOR A ONE TIME USE BOTTLE OF SOLAR CLEANER OR $35 -$40. FOR A BOTTLE THAT MAKES 500 GALLONS! IT'S A NO BRAINER!The concentrated cleaner was excellent for dust and dirt cleaning and minor degreasing of my solar panels. If there is no mold the product is excellent.Where it was average was during removal of mold growth. I followed the directions of mixing and application with the pole squeegee, but the mold growth was very difficult to remove. I even pre-soaked the panels after my first attempt and the mold still would not come off easily. I upped the concentration of the cleaner but still had difficulty removing the mold. It took a lot of passes of hand rubbing with the microfiber squeegee and constant applications of the mixture with a spray bottle before the mold was removed.I hope there is a better way to remove mold, because it was very time consuming and a lot of physical work involved.To clean my solar panels it’s worth it but It kneeds something to measure the liquidJUsed it on my solar panels. Worked like a charm. Dirt just vamished. Wish I had known about thuis years agoBought this one after reading reviews and absolutely love it. Solar panels look brand new after cleaning using this product ( having our panels over 2 years, first time cleanning). Can't wait to see how it improves.ExcelenteEs un producto que cumple con lo que yo buscaba, facil de usar y trabajar en las superficies de los módulos solares, en pocas palabras cumplió con lo que buscaba