Now that I have decided on using my RO/DI water for filling my tank, now I move onto plumbing..,..

How do you all tighten bulkheads? Hand, or do you take a wrench to it? I once cracked a 20 gallon tank tightening them just a "LITTLE" too much...any golden secrets (silicone, wrench, ...... ???? ) to tighten these things without OVER tightening them?

Thanks,
Ismael