thing are dying

Question
My fish seem to be doing fine but the rest is not one of my feather duster died, my open brain won't open up, my sanddollar died also a bigger hermit crab and I think my purple lobster did to also I aven't seen my lettuce nudibranch so i assume he is dead to my leather toadstool (not shure about the name) does not open up en my gorgonia (yellow) is thinning there is some stuff growing on the rock that looks like sand and on one rock there is these pods growing that have blue balls inside of them. I did a water change and added a buffer for low PH calcium is fine and I had low sal .018 I keep adding salt but it seems to disappear.
everything else is where it is supposed to be.
Please help before it is to late.
It is a 75 gallon tnak and i'm in the process of converting it all to a 125 gallon tank.
Thank you.


Answer
Diana,
What type of water do you use when you do water changes?  If you are using tap water it is possible that there is some variety of heavy metal or something coming in that is toxic to inverts.

If that's the case, I'd recommend using reverse osmosis filtered water (bottle drinking water) for your water changes and potentially use a product like Kent Marine's Toxic Metal Sponge to remove any harmful metals in the water.  It might not even be a bad idea to use a Poly Filter to asborb any excess organics or toxins that might be in the water.  The cool thing about that is that it will change color depending on what it is pulling out to help you determine what was going on in the water.

Also, what are you feeding the tank?  Have you ever had phosphates tested?

Best of luck with the tank!

Regards,
Scott Johnson
Aquarium Crazy Fish
www.aquariumcrazyfish.com