Lytag is very cheap but also porous,whether or not it is anywhere near the surface area of Siporax is debatable,i think probably not! however ive used it over many years and its without doubt very good media,if you only have a Fx 5 or similar to fill then you might want to go with the Siporax or something similar,theres lots of good media on the market these days.The fact i have many thousands of pounds worth of Rays in my collection,some of which i could never replace if anything went wrong with the filter system must show how much confidence i have in this product.
Water straight from the tap using declor from a syringe,not ideal but again ive always done it this way and had good results,with 3 kids 2 large dogs also theres only so much time in one day.
Cheers!