I can't say for certain, but I have used stuff from the hardware store that was listed for water use(2 ton strength, slow cure 30min), and I have use the stuff I build rockets out of, I think it is called "Great Planes" 15min(med cure) Epoxy. Have used both of these with no adverse effects. Sorry, I can't be of more help. I always let cure for a full day or two before using in the tank, I don't know if it matters or not.
Matt