Substrate dilemma for upcoming 300 build

[Jackalmore]

I'm gathering resources for changing my 300 gallon freshwater display and turning it into a seahorse/goby tank (The tank will be moving to a new home in a year most likely, so thats when I'll make the change). I'm starting from the ground up, which means nailing down substrate. I'm unsure of whether I should use a DSB or SSB. Denitrifying bacteria certainly is tempting, but on the premise of maintaining supreme cleanliness, I'm not sure if its the right choice because I've heard that old spots can rot/trap gas/etc. Barebottom isn't really on the table. I'll likely do a large amount of display macros, as well as a refugium in my sump. What do you guys think?

I also was curious if there was a chance I could salvage some of the sand I currently have in the 300. It was live sand when it was introduced (obviously not live anymore). Caribsea Tahitian Moon Sand and Caribsea's basic Arag-alive sand. There's 300 lbs of it in this tank at the moment. With some good ol' tlc, could it be used or should I start from scratch?

Photo tax of the new 20 long because everyone loves pictures

 

[shred5]

What kind of gobies? If sand sifting you will need a sandbed. Shallow is hard for them too because I tried it once and he piled all the sand up in one spot.

If not keeping something that needs a sand bed you can easily go shallow with proper filtration like a skimmer or fuge and enough rock. i mean people are successful bare bottom.

I have been in the hobby long enough to have tried all 3 and all three work.

 

[Jackalmore]

I'd probably have sifting gobies