also some of the rio's are more plankton friendly than mag/maxijet

How do you know? I don't disbelieve you, it's just that this
(plankton mortality in pumps) is a subject of real interest to me
and I'd like to know what information you have.

its been published before, its not so easy to find but its out there on the vast internet,
but basically certain things can go thru certain pumps at certain rates, and id have to
search for the data.

some of the rio's fall into this, and in every category that *I* am interested in a rio
180 fits for some thing it needs mods for others doesnt the 1100 is another that fits into
some areas.

in every case when the pump is not made specifically to work with things like phyto it
requires a careful exam and sanding down any imperfections from when the plastic went thru
the mold or whatever they do it can leave lips or extra small pieces. along with that no
pump is 100% plankton friendly you have to pick your planktons and guage how much harm
is acceptiable, a note i did say "more plankton friendly"!

a starting place you can pump rotifers thru a rio 180, they will live, they will drop
there eggs so you cant use it in the culture, but you can use it to move the cultured
rotifers. it also means you can use it in a rearing tank (but you *must* keep the fry out)
a parastolic pump is the same way if you set the rate up to high they will drop there
eggs, the catch you can turn down a parastolic pump you cant really turn down most
powerheads (closing a valve doesnt cut it) most of the smaller 30micron zooplankton
things like cilliates are also safe going thru a rio 180

copepods are the same as rotifers if you have the pump within the culture container you
will kill the culture, by removing the eggs but you can use them to pump from the culture
into your tank

another angle most pumps will pump nano without harm, even inside the culture container
but only a few will pump tetraselmise the cell wall is to thin, the cells break down and
you begin to pump mush. however you can modify a rio to be able to pump tetraselmise its
not hard some sanding here and there shorten the blades on the impeller and away you go.
that same modified impeller will now also pump baby mysis.

id have to dig around to be certain of all the models. ive already selected them, so I
know that the ones I picked were good, and past that I didnt need the data.

--
Richard Reynolds