Originally Posted by Pasfur
Understandable. I would offer that there were organic waste deposits inside the rock which died in transit, or perhaps detritus accumulation that was stirred up in your system with higher water flow. Either could spike phosphates. The same could happen in an older system if the rock was moved around or water flow was drastically changed. Would offer a decent explanation i'd think.
Very good points and i thouhgt of all those points, however the rocks were instantly transfered from my old tank to the new tank and so there was no die off in the rock. In the old tank ii wasn't using RO/DI for topoff or salt mix. the freshly made ro/di test salt water was in a new tank with no sand, no live stock, just water circulating and the suspected LR. Within a few days phosphates. I still believe "sponge effect" I know this is kinda change of topic but i figure it was important enough to debate. if you think we are off topic i'll stop posting this discussion here and maybe we can discuss in another thread.