Help with di vessel

[mark2788]

I'm thinking of getting a small back pack system, mainly using it for gutter and conservatory roof jobs atm but a deal on wcw for unger hydro power ultra plus big boy backpack has me thinking if that's a better option so I could potentially use it on certain larger jobs. The problem I have is I'm in a hard water area and wondered how long roughly resin lasts? I wouldn't use it alot maybe not even every week even,so would this di vessel be appropriate to start? 

 

[Iron Giant]

I'm thinking of getting a small back pack system, mainly using it for gutter and conservatory roof jobs atm but a deal on wcw for unger hydro power ultra plus big boy backpack has me thinking if that's a better option so I could potentially use it on certain larger jobs. The problem I have is I'm in a hard water area and wondered how long roughly resin lasts? I wouldn't use it alot maybe not even every week even,so would this di vessel be appropriate to start? 

Have a look at this https://gardinerpolesystems.co.uk/Resin_Calculator.htm but long term those  unger units and the resin are expensive potentially you may deplete the resin in one of those resin bags on one job