Been out of saltwater for a few years but getting back in, have about 300 lbs of dry rock how long before it becomes usable after I seed it, assume fowlr would be quicker than corals but what time frame
I soaked mine for 6 months in saltwater.... However if you're talking about just cycling it, there's a lot of variables but I think its safe to say, a few weeks.....
I added fish 2-3 weeks after using just dry rock for my 187 gallon tank. I jump started the cycle with some nitrifying bacteria and ammonium chloride and added fish when it was done. I waited another month or so before adding some corals.
You're asking how long does it take for the bacteria to build up in the rock to support the bio load you want to carry. And the answer is that it depends. It depends on what you put in to seed the bacteria, either bottled culture or something more traditional like a decaying shrimp, and how much. You can measure nitrate/nitrite/ammonia as you go and get good levels, but if you substantially increase bio load by adding fish, it will take a while for bacteria volumes to catch up to the load, and your levels can spike. So take your time.