fren i work at GNC. how much water is depending on ur taste bud meaning, if u like thick shake then not tht much water, n vice versa. 1 cup is around 400 grams, if u mix too much water u might feel super full, but if u mix too little water water u might get choke by it. hence, just mix wif the amount of water that u think its ok will do.

please dun follow the serving, because full serving is 3x400=1.2kg of powder.

u can take the weight gainer at these timing: after wake up, after work out or before u sleep.

to gain weight, u can try to take some vitamin B to increase ur appetite, as well as improve ur carb n protein synthesis.

basically, maintain ur daily solid food intake. count like this:
if u take 1 cup of 1850 (w/o milk), u get extra approximately 500 calories.
if u take 2 cup of 1850 (w/o milk), u get extra approximately 1000 calories.
if u take 3 cup of 1850 (w/o milk), u get extra approximately 1500 calories.

to gain 1 pound, u nid 3500 calories. but u use up calories as well as put ur body metabolism rate in the consideration too.

hopefully with this, u can roughly know ur progress n know wat u r taking.

result still depending on ur workout diet rest then only supplement. dont rely too much on supplements if can, natural source of food still the best. take more complex carbo.