Dessalator D60 Question..

[monte]

I have a quick question regarding watermakers
I had a dessalator D60 installed 3 weeks ago in France when I picked up my new lagoon 380.
Its not working properly. It seems like a good simple system. It has an automatic water quality electronic board that lets good quality water flow to the tanks and cuts off if its not good quality. It just requires to turn on the pump then adjust a small pressure dial till the pressure is in the green zone. A few seconds later a light comes on and it says good quality and starts to flow. I checked the water quality yesterday and it says 140ppm. I guess this is OK. The problem is keeping the pressure in the green zone takes continual adjustment as the pressure slowly rises to Red or drops to Orange zones (maybe after 3 or 4 minutes, sometimes 10 minutes. I noticed in the installation manual it says the pre filter must be installed below the waterline, however it is insltalled about halfway (the waterline is midway on the filter) . Do you think this may be the issue with getting consistant pressure? Do I need to lower it and why should it be below the waterline? Perhaps so no air can enter the filter when its not running and cause bacteria?
I also noticed the filter is quite dirty already, even though we have only managed to run the WM for 4 hrs on and off. The other thing they told us was to keep the fresh water flush valve closed. I have since read in the manual that this should be left open so the WM can self fluch after use for 30 seconds. Id be interested to hear your thoughts. At first when they installed it I didnt want to run it too much because the water wasnt perfectly clean near La Rochelle, but we have since ran it in very clean water, so Im not sure why the prefilter would already be quite green/brown, up to halfway through the woven thread in places. I will change the filter today as well.
Thanks for any advice you can give.
Monte

[dirkdig]

Congratulations on the new 380,
Cant help with your watermaker.
It was 2.5 deg in Torquay this morning.
Enjoy France

[monte]

Thanks Mate ! Im in Spain now..La Coruna, heading down towards Portugal..you dont wanna know about the weather here! but I notice theres some swell headed your way

[dirkdig]

Hope there is swell coming,i just got to Bali for 2 weeks.

[monte]

enjoy it, catch a few for me