RODI then Salt @ Startup of new tank

niccumec · Feb 17, 2024

Getting close to adding water to new 170gal tank. Ideally, I would prefer to fill with RODI (not expecting major issues with leak testing) and then add salt after I see all plumbing tests put okay, mixing salt directly in sump / DT. 150 gal DT, 75 gal Sump, 20 gal Ext Refugium.

The question I have is if I go this route, I would still like to first add live sand (Special Grade Arag-Alive! Reef Sand - CaribSea) along with my Marco aquascaping rocks. Will the pure RODI harm the live sand while waiting for the following salt mix?

Harpo · Feb 17, 2024

I would expect that RODI would kill your live sand (assuming it came out of the ocean)

BigAl07 · Apr 11, 2024

How much "Live Bacteria" is really in those bags of Live Sand from CaribSea sand bags?
I'm literally just a few hours away from doing exactly what @niccumec is questioning. I am going to add the bags of CaribSea Live Sand, then start the RODI into the tank. My estimation is it's going to take about 34 hours to get everything completely full since its having to push the water 75' away and UP to the 2nd story. I won't be running it 24/7 "just in case" so it will take approximately 3 or so days to fill. Then I'll add salt to the mix and just wondering how MUCH actual LIVE BACTERIA is really in these bags???

@niccumec what did you end up doing in your new setup?

niccumec · Apr 11, 2024

Just finishing the process right now. I ended up filling with RODI and did all of my leak, max pump rate, and backflow tests. I also hooked up my AWC / ATO dosers and ran them through the tests. This ended up working well for me as I ended up going through a learning curve with the GHL programming and equipment. I also noticed more “dirt” in my filter socks than I would have expected with a brand new system. I guess flushing everything thoroughly with RODI has that benefit as well.

All went well (except for one of the 100 connections that failed to get cemented!!! (OOPS). I drained the tank and sump of RODI - which is easy for me as my system is hard plumbed to my main drain. I added the sand first and then started filling with SW. I am going with 20PPT recommendation by Dr Tim to aid the bacterial cycle and then will ramp up once cycled.

Even being careful with the sand, I got a pretty cloudy tank. Hope it clears in the next day or two. Still not sure about the “live” part of the live sand, but hopefully there is some benefit.