Here's a good write up on how someone else has been hunting them for what it's worth. http://reefkeeping.com/issues/2006-02/bp/index.php It looks pretty thorough.
A branching hammer has recently lost it's color and I've been frantically checking water parameters and everything else I could think of to determine what is going on. Some of the other corals have had limited polyp extension as well.
I swapped out heaters and of course had to adjust their...
I was also given some replacement cartridges though they are not SpectraPure's brand. The third cartridge, which I believe is the deionization cartridge, has no label and looks a fair amount different than the pictured cartridge on SpectraPure's site...
I did a quick check that the ATO controller is working by sucking/blowing on the air line going to it. I did hear a clicking sound. I'll go ahead and test the solenoid as you describe as well.
Do you think I should go ahead and replace all three of the canisters as well as the RO membrane or...
Here's a pic of the back side of the system. The black cord from the ATO unit can be seen attaching to the yellow cord which is attached to a device at the end of the blue hose. Is that a switch there? It looks too small to be a pump.
Thanks much for the responses. I believe I found the described meter.
The dangling plug from the right side of the first pic does fit into the right hole of the meter. Any idea what the other hole if for? The hole doesn't have anything attached to it on the inside.