It really depends on the person. You could start with equal carbs and then increase week by week based on progress. Carbs don't cause water retention, having a shit diet does.
I've ran as high as 1,400mg Tren Ace before... Back in the good ole' GH15 days - more of an experiment than anything.
I really like 700mg of Ace a week, thats about as high as I go now, and thats only the last couple weeks during a contest prep, never touch it otherwise. In all honesty, I noticed no difference in doubling the dose (keep in mind it was only for a week and a half - but still).
Been using Genetec for a while now exclusively. Great lab and products. Rep is awesome. Fair prices. They are the real deal and one of the top UGL in Canada.