Applying Biocide with Gardiner back pack?

Hi all,

Im thinking of a easy way to apply some biocide to the odd roof. I have a spare pole and some hard brushes to hand.

I was thinking, could i use the GARDINER PURE WATER BACKPACK V3 - 22 LITRE to apply the biocide. Would it be possible to remove the filters to use it purely as a applicator? 

If not.. is there anything on the market similar? 

If this would be possible, it would be perfect.

Thanks in advance 

Gardiners back pack is ideal for this it will work fine but the flow isn’t great so it will take a while to apply it to a roof . Just rinse it out well after