Guys thanks for al the compliments and nice words. The tank inhabitants need two thinks with such a big tank. They need to be beatifull and effectiv ( so they can do the work for you) The frontosas is for cleaning up the food left overs, from the rays in the small spaces and the Zambia Bleu variant is also nice and strong enoung to resist the group of Asian Aros comming in this tank soon. The sand we use is more a fine gravel od 0,75 and 1 mm fine. Does not stick to the rays.
Regards
Frank