I started with something liek 8 guppies all of them died but 2 each in a different way, I watched one slowly just stop swimming.
I decided that it was nothing I was doing wrong. The one male lasted quite a while, and at one point even got stuck under a plant in my tank for several weeks to reveal one day that he was still alive. He has passed on now, jsut started staying at the top of the tank, then just before I went out of town starting darting here and there and just sinking etc. He darted into some thick plants and I have never sceen him again to this day...
However I went from 8 to 2 to 100's of guppies so many I have to sell them or give them away. I have not experienced many deaths of my own guppies, jsut the ones that came from the LFS's it could be that they were jsut on their way out when you got them, or that they could not deal with the stress of being added to a new tank.
yes, this should be fine. I wouldnt move over much of the water though, and dont let the gravel / filter media dry out. Oh, speaking of filter media, its not neccessary to replace them every month or whatever is "recommended" (I know you didnt say anything about this, Im just throwing it out there.). You will be fine with rinsing in a jar of old tank water every other water change, until they are falling apart.
Actually, bring the water down by about 10%, have your stand ready, and two people can usually pick up a 10G nearly full. With a 10G tank you are looking at approx. 100lbs.
hi there, i have a dozen fancy guppies in my roughly a metre length tank,
inside i have a driftwood and some cabomba plants, and a few shrimps.
guppies are very hardy creatures from my experience and they do well even with new tap water.. just takes them some time to get adapted..
probably you could try after changing the water, don't touch it at all, don't add the salt or stuff, and see how they do.. also are they healthy to start with? a possibility could be that they're already sick to begin with.. look out for white opaque spots, shredding of fins etc..
also, guppies love companies, hope that helps! all the best.