To follow on... I've been off quite a bit so the equipment hasn't been used anything like you would expect in a four month period.
The issues I've had with the system are - the battery doesn't hold it's charge, there is no visual guide of the water level, there are no fill or drain ports, poor fitting of the plastic panels and the bolts on the reel and panels started to rust soon after purchase, the 100m hose doesn't fit onto the reel and it's wearing the hose down and keeps jamming the reel.
Remedial;
Battery - not had a reply yet. Fully charged it's over 14v and before use drops to under 13v (in a day or two)
I've just fitted a ball cock valve with a fill connection running to the front of the tank which helps a lot.
For a gauge l need to fit something like the following;
http://www.ebay.co.uk/itm/1-6-ft-457mm-Tank-Float-Gauge-with-Back-Nut-Suits-Oil-or-Water-Tanks-/272173239629?hash=item3f5eca0d4d:g:NfcAAOSwgQ9VgZgEhttp://www.ebay.co.uk/itm/2-52mm-Universal-Car-Fuel-Level-Meter-Gauge-With-Fuel-Sensor-E-1-2-F-Pointer-/161981360973?hash=item25b6d76b4d:g:714AAOSw~OVWxWAbAlthough I'd rather not fit or modify anything and especially anything electrical as it defeats the purpose of buying a ready made and purpose built system. I need a simple and reliable indication of the water level and with the tank lid being at the back of the pickup it's not an option to just look in it!
Drain port - I could do with a bilge pump as now and then I will need to drain the tank and it's not great having to syphon it.
Plastic panels were removed and I've drilled new holes so they line up correctly.
Rusty bolts - wipe them with an oily cloth or completely remove rust and spray with lacquer.
Hose - cut off around 15 meters and be left short for those further away jobs or fit new connections to the cut section and attach when needed or buy a new backpack. During use the hose is only going to stretch with warm water (NOT HOT WATER) and summer use so a fair chunk of hose will be lost.