I know that this is late in regards to ESS 13 but hopefully it will prevent someone from making the same mistake we did. We put it in our reservoir and it was totally useless and they did not stand by their product. Their supervisor left before the job was completed saying everything looked great - then when it leaked like a sieve he was blaming the contractor. If you have $30,000 plus to waste, then give it a shot but we had clay and mixed it under their supervision and it never held water. We finally had to put in a vinyl liner. Wish we had just done that in the first place. ESS 13 is a total waste of money. Awful product - Awful company.
