I had a 700 reef tank that I lost after a disaster when I was away on vacation several months ago
. I had a gasoline leak in my garage which fumigated my entire house and within a short timeafter my return everything was dead. Sparing details, I am trying to get it up and running again with fish only this time. Seem to have multiple issues. Have done multiple water changes since I lost everything. Also ran carbon filters trying to get toxins out. Waited 6 months with just filtration and skimmer running. Water is a little cooler now @ 72 since metal halides not running all the time. pH is high at 8.5-8.7 from continuous monitor and won't come down. My city water supply pH is rediculously high at 11.5+ so my r/o water is at about 9.0 when it goes into the tank. Have a level sensor that does it automatically. Nitrate, nitrate, ammonia levels all good. Have snails as only living inhabitants presently and they seem to do fine. Tried to introduce 2 damsels recently and they were dead in <24 hrs. Dont think the pH and temp are at lethal levels (or are they?) but open to suggestions as what to try next. Not really practical to completely breakdown this entire system and I'm hoping to not have to go that route.