Adding a tank in series/parallel
 

I have a 90 gallon reef with a 30 gallon sump/fuge.
I added another 30 tonight. I tapped off my return pump to run a low flow through this new 30. Right now the new 30 is just all glass with no sand or rock. My intent is to use it as a larger refugeum and maybe down the line a seahorse tank/fuge.
Now my question is if add live sand and rock to this tank should I isolate it to cycle? or is that not necessary?

Thank you

I wouldn't bother with live sand - what's in your system now will spread over soon enough. Dry clean rock will be ok too, but if you want to seed it with a piece of good fresh live rock it can't hurt. I wouldn't expect a cycle at all if you go that route.

Like said above I would go all dry. Nothing to worry about and it will become live.

Don't be adding uncured stuff to it, obviously, but no cycling required. It's no different than adding a piece of dry rock to the mains display. It will quickly be colonized.

Thanks all! I had a feeling going that way was the way to go, but just wanted some experienced opinions.