Good morning all. I have what I hope is a simple question. For the past three years I have used a 65 gallon water tank to store filtered and treated water. I filter through a solid filter and a carbon filter and then treat the water with cambden. The tank looks like this:
It is polyethylene. I have only ever had water or star San in it. Over the winter as ground water gets more organics in it the tank tends to smell of organics. I don’t leave water sitting for a long period of time, but the smell is definately there. What can I safely clean the tank with? It’s max temp is 120F, so I’m concerned about using pbw and getting it rinsed out etc. Any advice? Thanks.
You can use PBW or Craftmaster to clean it. I will rinse out just fine. I had a conical fermenter made out of basically the same plastic and it cleaned up nicely and rinsed out easily. You need to kill the organics first and since PBW is a form of caustic this will take care of the organics. You should agitate the cleaning solution to make it work more efficiently. I would then use an acid rinse to get any inorganic residue out of the tank. You can use something like Star San at a dilution of 1 oz per gallon or find an acid cleaner for bulk milk storage tanks at a farm supply store (which is what I use as an acid rinse and to passivate my stainless steel vessels).