Renew tabs are bromine tabs so you have a bromine spa, not a chlorine spa. That's fine if that's what you want. You may need to shock with chlorine every one or two weeks to keep the water clear. The advantage of using bromine tabs is that it doses your spa with a background dose of bromine so you don't need to dose in between soaks. However, if you have at least one person using the spa every day or two, then you could have a chlorine spa instead. The downside with a chlorine spa is that it needs dosing every day or two, but if you use the spa that frequently then you just dose after each soak. Up to you.

For a chlorine spa, you start of using Dichlor initially until you build up the CYA level to 30-40 ppm and thereafter switch to using regular unscented bleach (NOT splash-less or outdoor).