thank you for recommanding Berkley water I didn't know about this program, I'm grateful.
I also found this video for those who might not be able to efford the whole system (however, if someone can consider getting the whole thing) note I did not try this more economical (note berkley filters need to be regulary used that is fully submerged, unless you leave for 2 max 3 days trip) if you decide please investigated further, just found this video and in case someone might benefit from it here it is:
it is my understanding that stainless steal is better, more resistant to algae / bacterial growth.
with love to you, your sister BarBara