Continue to use your refractometer and use the money you would have spent on a digital meter towards new lights or PH's. You should definately order lights and most equipment online. The local lfs
just can not compete on price for hard goods. Livestock is different if you have a good lfs
You may want to use that saved money to buy a RODI
unit. There are some inexpensive units on eBay for around $100.00.
from the tank probably has a lot of die off if the tub is not heated and has no circulation. Depending on how long it takes to get the new tank set up the LR
might be usable as base rock only.
You can add a heater and a ph now to help keep it alive. You should test the tub water for pH, ammonia, nitrite and nitrate. You may need to do water changes in that tub to keep the LR
Clean the tank thoroughly (use white vinegar if necessary)
Rinse the tank several times with tap
Add the rock
Add the sand (new)
Add fresh SW
Let the tank cycle
That's the short form of what I would do.