Before I get started sorry about the novel.
A friend of mine asked me to come over last night and take a look at his tank. He's been having problems keeping any type of coral or invert for a couple of years now but can't figure out why. Even the easiest of corals such as mushrooms seem to perish quickly, but at the same time his fish are very healthy. I have a theory but before I get into it I want to give you some back ground information on his tank.
90 gallon
100-110 lbs live rock (had it for 10 years)
Prizm skimmer
Ehiem filter (not sure which model)
Salinity 30ppt (haven't tested other chem levels with my salifert kits yet, but they should be within reef keeping ranges according to his recent tests)
2x 150 HQI with 4x65 watt PC actinics
4 various power heads in tank for flow
Doses 2 part CA/alk, MG, trace elements, iodine, etc.
Changes 20% to 30% every two to three weeks.
According to the above information everything looks ok right? I thought so, but after further discussion I started to develop a theory about what might be happening. As I gazed into his tank I noticed that his LR has absolutley no coraline algea on it. This struck me as odd, because even the grappiest base rock is prone to gather at least a bit of coraline. We got to talking about RO units when he told me that he has never used filtered water with the acception of a 5 month stint a couple of years ago.
I gasped! You see his house, as beautiful as it is, is quite old and uses copper plumming. So I asked what he used to treat his tap water? "Nothing"
I gasped again!
Now, before I point the finger at this malpractice as the culprit, I think we should keep an open mind about this, because we all know someone who used tap water in thier tank. Which may inhibit reefkeeping greatly in some cases but remember though, this rock has been in this tank for 10 years!
My theory is that prolonged exposure to copper and other heavy metals is what keeps killing his corals. Not only that but his LR has actually built up toxic levels of copper over the past 10 years. So that the LR will leech(sp) copper into his water even if he switches to filtered or treated water. Thus rendering his tank useless for invertabrate growth.
Does this seem like a valid theory to everyone?
I told him he may have to get rid of all of his LR before attempting to keep corals again. Possibly the tank as well, but I'm not sure how copper affects things like glass and silicon.
Thanks for your input.
Danny