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There is something I’ve been wondering about for awhile now. What determines the best average pellet/granule size of your bio-media versus its application? In other words why would you choose smaller or larger chunks of something for a particular filter set up? I know that if all else except average pellet size of the material is the same; the smaller sized pellets will have a greater surface area per volume of material and also pack tighter. So a greater surface area gives more room for the bio-film of beneficial bacteria to colonize.
The reduced flow due to packing tighter may decrease the oxygen available to those bacteria and be a limiting factor. I’m also thinking that on a high flow filter like a Eheim 2262 the increased dwell time of a media density imposed lower flow rate could be beneficial in some cases? I also understand that larger particles will have a lesser tendency to act as a mechanical media, and will allow detritus to pass through without getting trapped as much in the bio-media as much as a smaller average sized pellet media would. Of course if you are using a mechanical filter pad prior to the bio-media—that aspect would be rendered moot as the stuff you might be worried would clog up your bio-media would have been stopped downstream.
The products that got me interested in this question were SeaChem’s Matrix and Pond Matrix bio-medias. SeaChem claims Matrix provides 4-4.5 times the available colonizable surface area of Eheim’s Substratpro, and additionally has some pores small enough and oxygen limited enough to support denitrifying bacteria as well (they recommend De*Nitrate for that purpose in set ups with less than a 50 gph flow rate). The regular Matrix has a smaller granule size, similar to Eheim’s Substratpro media. The Pond Matrix is a fair bit larger in diameter. Both the regular and Pond Matrix are available in 4L buckets and are priced about the same by most online retailers that I looked at. I’ve looked at the FAQ and info sites on the SeaChem website. The only difference I can see is that they recommend the Pond Matrix over the regular matrix for wet/dry applications. I guess you would need a fairly sturdy wet/dry to accommodate the weight of the Pond Matrix over say bio-balls in the first place?
I’ve never had a firsthand look at Eheim’s LAV. How does the average granule size compare toSubstratpro, and where would you choose to use LAV over Substratpro and why?
The reduced flow due to packing tighter may decrease the oxygen available to those bacteria and be a limiting factor. I’m also thinking that on a high flow filter like a Eheim 2262 the increased dwell time of a media density imposed lower flow rate could be beneficial in some cases? I also understand that larger particles will have a lesser tendency to act as a mechanical media, and will allow detritus to pass through without getting trapped as much in the bio-media as much as a smaller average sized pellet media would. Of course if you are using a mechanical filter pad prior to the bio-media—that aspect would be rendered moot as the stuff you might be worried would clog up your bio-media would have been stopped downstream.
The products that got me interested in this question were SeaChem’s Matrix and Pond Matrix bio-medias. SeaChem claims Matrix provides 4-4.5 times the available colonizable surface area of Eheim’s Substratpro, and additionally has some pores small enough and oxygen limited enough to support denitrifying bacteria as well (they recommend De*Nitrate for that purpose in set ups with less than a 50 gph flow rate). The regular Matrix has a smaller granule size, similar to Eheim’s Substratpro media. The Pond Matrix is a fair bit larger in diameter. Both the regular and Pond Matrix are available in 4L buckets and are priced about the same by most online retailers that I looked at. I’ve looked at the FAQ and info sites on the SeaChem website. The only difference I can see is that they recommend the Pond Matrix over the regular matrix for wet/dry applications. I guess you would need a fairly sturdy wet/dry to accommodate the weight of the Pond Matrix over say bio-balls in the first place?
I’ve never had a firsthand look at Eheim’s LAV. How does the average granule size compare toSubstratpro, and where would you choose to use LAV over Substratpro and why?
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