Hi all,
Sintered glass has probably the biggest surface area which makes possible to attach lots of bacteria. I do not like it i have to have to change it every half year.
It is all smoke and mirrors.
You never have to throw it away, you can just rinse it and carry on for ever. If you are worried about the deeper micro-pores being blocked you can microwave it.
I've actually got sponges that are 10 years old and still OK.
K1 is mainly used in sumps where air is flowing trough. I can't provide that.
It is fine in a canister filter, if you contain it.
Manuals heads up on eventual risks of toxicity when using sintered glass.
It just isn't true. If you supply sufficient oxygen it is never going to develop the zonation you would see in a <"
Winogradsky column"> (in Manuel Arias's schematic).
The real danger with all canister filters is that the media becomes de-oxygenated and then ammonia levels rise, causing lower oxygen levels, causing higher ammonia levels, causing lower dissolved oxygen levels
ad infinitum in a positive feedback loop.
In a non-planted system biological filtration in a canister filter is always <"
single point of failure">, and this is exacerbated by trying to have simultaneous aerobic nitrification and anaerobic denitrification in the same filter.
I like any mechanical filtration to be in an (easy clean) pre-filter and I don't want anything (like floss or fine (PPI30) sponge) in the filter.
You can achieve nitrification and denitrification in the substrate or by using a HMF, or trickle filter, mainly because they have access to oxygen from the tank water and air, but a canister filter doesn't. A finite amount of oxygen enters the canister, and it can't be replenished once it is in the filter.
A lot of people don't understand this, or why oxygen is so important. About ten years ago I wrote <"
aeration and dissolved oxygen..">, largely based upon my experience working on the biological re-mediation of landfill leachate, and I would say that it has stood the test of time remarkably well.
I've read that when you look with a microscope there is a big difference between regular pumice and pumice that ADA or Seachem use. So it's not "just" pumice that the brands sell. And your able to just rinse to clean and reuse.
There are
<"pumices with lots of different chemical composition">, it depends upon the geology of the volcano they were ejected from.
However I would be surprised if any commercially exploited sources of pumice aren't derived from rhyolite (you only get huge volcanic explosions from silica rich magma), and you only get commercially exploitable deposits of pumice from huge explosions where the pumice has ended up in a lake or sea (on land large deposits will form welded Tuffs under their own weight).
You can re-use pumice, in fact you can treat pumice exactly like a sintered glass media, because they are basically the same thing. Are ADA's or Seachem's pumices better than horticultural pumice in use? I don't know, but I would be very surprised if they are.
cheers Darrel