Any of you guys use or consider using the following products:

[You must be registered and logged in to see this link.] (prices for products and installation is quoted on the site)
[You must be registered and logged in to see this link.] (this site has been mentioned before on here)
[You must be registered and logged in to see this link.] (uses a quarsite coating)

Seems relatively economical but I am not sure if it is suitable for koi given that they state the use is for pools? Anybody use this for their pools (evidently I might have to refurbish my mother in law's pool in the next year or so) or koi ponds?

Thoughts?

Regards
Haggers