When this card is Summoned: You can create a number of Ice Counters equal to the number of WATER monsters you control, place them on a face-up monster(s) your opponent controls, then, if you placed 3 or more Ice Counters by this effect, you can destroy 1 card your opponent controls.
How to Get
Destroys your opponent's Monster Cards / Destroys your opponent's Spell Cards / Destroys your opponent's Trap Cards
I've tried and yes, you can.
You have to summon it yhe 3rd card so that you can collect 3 counters immediately. Your other water monsters must be face-up so that it's counted as three cards.
If it has 3 counters, you can destroy any card(face-up/down, spell/trap card)