I was going to ask if anyone ran two, one on the low side and one on the high side. I am thinking about doing that.It’s better to have and not need, than to need and not have. If it’s a budget thing then the icecap model wouldn’t be a bad option. It can be annoying to get sealed correctly, but for a 40 watt UV delivered to your door for under $300 it’s a great deal. I run two on my 150 gallon.