using QUIKRETE Concrete Acrylic Fortifier in rockwalls

[issac]

so I'm still working on building the ideal rockwall for my viv, currently I am using one made with polyester resin, but I dont really like the effect. After looking for new solutions I came across the dutch method using flevopol (sp?) and attempted to find a suitable alternative. Leading me to QUIKRETE Concrete Acrylic Fortifier, the only problem is that when the stone (sand/coco fiber/ fortifier mix) is placed in water it becomes loose again, and the coco fiber fortifier mix turns to mush. Is this not a good alternative? or are my mixture proportions just off?

thanks for any help