@Randy Holmes-Farley A question on bound phosphates in rock and sand. I'm assuming, at some point, phosphates bound up in my rock. My ph has been steady for the last 2 years between 8 and 8.2 daily. So, it sounds like for phosphates to bind to rock it needs to be in the 7.9 range. So, is there anyway to determine how much are bound up in the rock work or sand?
So, early on, 3 years ago this coming June, I lost 16 fish due to a variety of disease, all of where I discovered were onset from a heater that was electricuting the tank. It took 3-4 weeks to kill all the fish. Most of them went into rocks, buried themselves in the sand and disappeared. I got a few out, but many decomposed in the rock work. (350 gallon system.) My algae scrubber went nuts for about 3 months. I had the tank go fallow with just two fish that survived the electrocutions for about 6 months before I added more fish. Which allowed any phosphates, etc to be filtered out. My Scrubber eventually struggled to grow anything more than slime at the 4-5 month mark.
I'm hoping most of the organics were removed over that fallow period.
1. Would organics from 16-17 corpses be bound in the rocks now being released?
2. Every morning I see tons of amphipod skeletons on the surface of my tank. I would say it's in the hundreds of skeletons... All slowly being skimmed out through the overflows, but they just float around. I believe these are molts. Which is awesome. I have thousands and thousands of amphipods molting every night if that's the case.. Do molts contribute to phosphates, if they just float around on the surface of the tank?
3. My Dragon wrasse constantly is digging, moving rocks, coral skeletons (I left a few in the tank for him to play with) and moving my sand bed around -literally moving mounds of sand daily). Would organics in the sand being released everyday contribute to the problem instead of leaving it there for it to be broken down by bacteria in the sand?
4. The rock I used was in a previous 220 gallon tank, it had been in cold storage for 2.5 years (dry) I hosed it off, but didn't bleach or cure it when I reused it. So, previous bound organics were part of the new cycle...
Ultimately the question is, given the unique situation reused old dead rock, lots of dead fish corpses, and lots of decaying molts nightly, is there anyway to know how much is still in the rocks. Will it be years before the rocks come clean and release their last bit of phosphates, or is it just a matter of keeping the water column low and within a few months whatever is bound in the rocks will be gone if the water around them is kept at undetectable phosphates for a period of time?