I would like to know if you ever heard of a problem to a septic tank or leaching field from wastewater from marine aquarium water changes? I'm concerned about the salt crystallizing and the other chemicals that would be present. I would also like to know about removing unwanted polyps, mushrooms and such from live rock. Should I re-cure it by putting it in a dark tank with powerheads and skimmer until they die off? I have some pieces that are really overgrown and they don't pull off very easily. I'm going to be moving soon and I want to make some changes to less free spreading specimens so I want to keep them out of the new tank.
In closing, I have had good luck with my plenum system that is under my main tank, but my new setup will be in the main tank. I know to keep the rock loose and have good water flow and phosphate removers in from the start. Any other tips would be helpful as well.
Thanks once again [this must be the sixth letter to you] for all your help. You have helped keep this an enjoyable hobby. Two plus years and algae free.
Only six letters! A hobbyist in Cape Town South Africa and I have exceeded 135 letters over the past two years!
As for your questions, we live in the mountains and also utilize a septic system. I would never dump my old tank water into that system nor do we allow our clothes washer water to enter that system, as it is loaded with phosphate that would coat the walls of the leaching field piping and clog its ability to dispense the water into the adjacent soil. The same is somewhat true for the salt/minerals in seawater.
As for the polyp coated rocks, why not sell them to a local store before moving. If not a good idea, then simply drop them into a vat containing 'only' club soda and leave them there for a few days. Then remove, scrub clean, and place the rock in a dark vat of seawater until needed, which will help re-colonize their bacteria. The club soda bath will rid the rock of any unwanted worms, polyps, etc.
Hope this helps.