Darn… well I’ll keep hunting too!
If you don’t want the sparta/activeaqua, there’s northprint and 4dfiltration that sell acid free carbon.
How’s the aquapapa been? Their price is more reasonable than northpoint. Last I checked, Sparta was sold out. Same with another place that was recommended, Activated Carbon Depot. Will check the others you recommended.
Can’t complain. I’ve been using the aquapapa this whole time in my bento box and exhaust filter. I only gave other options in case they sell out or you’re not up for doing the testing (they don’t explicitly state acid-free in the listing so please test in case they change suppliers).
agreed, I emailed the seller and they told me it’s acid free, especially since it’s for aquariums and it’s preferred to be acid-free.
then i stumbled upon another post saying people who run aquariums prefer acid-washed. so who knows.
when i suggested the seller themselves or asking the distributer to explicitly state that it’s acid-free since it’s a preferred choice, they glazed over that and would not answer directly…
guess I’ll have to build something to test it myself since 3d printed dedicated ones are so hard to come by.
thanks for all your help on this @partferret