Naw, nothing detectable.
Calcium/Alk always good.
Phosphates non-existant
Nitratres/tries/ammonia always 0 (on that tank...)
Haven't tested for silicone/silicates/whatever, but I'd think that'd have to be it....
We'll see, I'm going to suck out water, pull rocks out, rip hair out, scrub a bit, refill with ro/di and go from there...