Diesel Kleen is good. I used it before, but I now use a mix of bio con and lucas fuel additive. The Bio Con prevents algae from growing in the tank. The Lucas is similar to diesel kleen. I was using diesel kleen because of how easy it is to get. Every where sells it. Walmart, any auto parts store sells diesel kleen. But I still ended up with algae and other gunk clogging up my pick up tube in my tank. That is why I switched to the bio con and lucas fuel treatment.