Based on a dozen tanks?
The first choice.
Based on an analysis of the sediments as well(if anyone besides myself has ever bothered to do so, I only know of one other person that did a simple jar test and no one that's done a basic soil test at a lab other than me thjat I'm aware of).
Try it and see for yourself if you doubt it.
Put your money where your mouth is.
I think powersand is a hold over prior from when Amano did not have ADA AS. Adding it will add some ferts in the start up period, but so will adding a little KNO3.....and then you do not have this nasty grey pumice all over the place.
ADA As has quite a bit of nutrient content on its own.
Sort of funny, all the converts carry on about the need, but without a single test or a single measurement of the very thing they want to argue for/about/suggest is a cause etc.
Even simple test like W or w/o PS added and then seeing the results based on growth rates.
Add a little bit more NPK at the start and then there's no need for PS.
If I got something out of PS and if it made even 20% of the difference ADA As did, then you'd have something.
Why bother?
Because ADA says so?
Come on, you have to do better than that.
Don't parrot what ADA says either, research your own conclusion and test it your yourself.
Unless you try both with and without PS using ADA AS, how on earth can you tell what is influencing the other? You cannot.
Even such simple methods anyone can understand eludes some however.
It's really mind boggling, then they get testy with me over it.
Don't be a personal jerk, show
the idea, the hypothesis is wrong and that you do get some measurable difference from PS vs say, adding some KNO3 to the bottom during the start up.
Try ADA As alone and see.
Etc......
then you can discuss it.
Regards,
Tom Barr