Reusing saltwater stuff

[Hanks Tanks]

A friend very kindly gifted me a ton of saltwater equipment and materials but I’m not ready to jump into the reef game yet. Inspired by Zenzo’s recent video on tips for beginners, I’m trying to think through freshwater applications for some of this stuff but I my googling isn’t leading me anywhere productive. 

Does anyone have experience with this and general advice on wasting and wanting not? The three items I’m particularly curious about are:

Kessil A80 Tuna Blue LED lights - they seem too blue. Am I just going to be fighting them trying to use them on a planted tank (relatively low light demands, no CO2)? 

Aragonite sand - how/can I effectively use this stuff as a buffer? I have extremely soft water and my planned tanks range from soft and acidic that I’d like to prevent from swinging dramatically to some with moderately hard water for livebearers. I’ve heard aragonite dissolves super fast?

Reef salt - can this stuff be used in the same way that marine salt would be for treating disease and stuff like that?

thanks for any help!!

[Patrick_G]

Wow, nice gifts! 
The A80 Tuna Blue lights have high resale value  but won’t be good for a planted tank. I’d trade over to some planted tank lights like a Fluval 3.0 or Chihiros WRGB 2. I checked eBay and I’m guessing you could get $100 per light if they have goosenecks. 
The reef salt has other stuff in it beside just sodium chloride so it’s not good for a freshwater setup.