You can most definately grow more than one strain in the same hydro grow. I've just harvested five different strains all growing together in a six-plant hydro grow. Got eight ounces of quality, finished bud out of it too. There IS a problem with doing this though. First, each strain has its own nute requirements. Some strains stretch more during flowering than others do. So ... some plants will try to take over the growing chamber and block light fromt the smaller plants. All of this will affect your end yields. For maximun yields out of a small space, you'd want to grow one strain at a time ... but how boring is that? *lol* Variety is the spice of life, no? For the grow I've just started, I've decided to go with only two of the strains I finished up with this last time. Both strains grow at about the same rate and end at the same height. So ... hopefully, the next cycle will produce between 13 ounces and a pound. Not bad from six little girls, eh?
Vi