Hi Jeff,
What you say about the ceramic noodles is very disturbing, my Fluvals 203 has been in operation for 20+ years with the same noodles so I'm going to break some open and see if its the same case. If it is then my long-standing aquatic faith in trusted brands like Fluval and Hagen will be as shattered as the ceramic! Im currently experimenting with rubber bands in place of the broken o-ring, maybe if I can find one the right thickness I can still use it, it would be handy to have as a spare.
Interesting idea with the rubber bands... although it's not like the filter owes you anything after such a long run time. Maybe try an automotive parts store, I think I recall seeing an assortment of sizes, perhaps they have a size that will fit... I think that you would need a round profile rather than the flat of a rubber band and they would last longer.
As for the Eheim Pro 3e I'm going to swap around the order of the media as you suggested, in absence of evidence that the default setup is more effective I'll stick to the tried and true system of coarse, medium, fine, then Substrat Pro then Bio-Mech as suggested. However those ridged black plastic tubes are giving me nightmares... the thought that Hagen could be charging a premium price for something that may be absolutely useless makes makes me mad as hell :evil: Since my temple of faith has dangerously cracking foundations I'm going to make one effort to underpin it and leave the 'Eheim Mech Pro' in the filter for a few weeks then see if it has caught any dirt. If not then it goes in the bin and I'll replace with some floss. I tried to set it up yesterday but there was not enough tubing included in the box :-( and hardware store is not open until Monday. Spray bar is way too short as well, around 30cm and the tank is 5ft ~sigh~ so I will join it up to the old Fluval one. When you pay $400 for something you shouldn't have to cobble things together.
I used a 5/8" soaker hose in place of a spraybar. Not only is it black and disappears but I can make it as long as I want and drill holes in it to direct the flow where I want and the added benefit of it also "soaking" out slows down the water flow a bit more... I want low flow. I went with a vertical orientation but with a couple of fittings you could do whatever you wanted.
As to actually proving that media works, to know for sure at least 2 tanks (more for more media) would have to be set up, including a control tank. Both tanks would have a bare bottom so dirt could be easily seen and so the majority of BB would be in the filter media not in the substrate with the same number and species of fish in each tank fed the same way, basically identical tanks with the same filter, the only difference being the media in the canister, the control tank could have sponges the other Mech Pro. After a period of time the Mech Pro tank water would have to be tested for particles and particle size to compare with the same in the control tank water. The same would work for biological media but you would instead test the water for ammonia/ammonium, nitrites/nitrates and possibly total dissolved solids (or conductivity?). The results would certainly be interesting but I don't have the equipment to do it and don't know how to test for particles though you could take a sample of water and pour it through a paper coffee filter as a visual aid. However there should be no need for us to do any of this since the manufacturing company should have done tonnes of research developing the product and that info should be available to us. I'm going to email Hagen and ask them to explain to me how it works.
I would be very interested to see what they say, I was thinking of doing that as well. For some reason I doubt that they did any actual research (anyone know different, chime in). In fact, I wonder where the original idea came from for some of the stuff that all the manufactures come up with. I started doing some comparative calculations for sponges, sand and , gravel as biofilm surfaces and when I got to ceramic I found that the porosity was so small as to be counter productive on a few levels. One of which was the required backwashing of ceramics to rejuvenate their effectiveness as a filter medium as it clogs up quickly, the small flow rates at low pressures... and even at higher pressures, the fact that they can filter out bacteria if small enough, which negates a biofilm setting up in the first place as it needs not only space for the bacteria/archaea to squeeze into but additional space for the film to establish then some leftover for the water to flow through.
The plastic stuff which is just so far on the other side of the spectrum.
I am far less concerned with actual particles in the water over water quality for the fish so I am not really aiming for crystal clear water but I tend to get that most of the time anyway by default, graduated filter media size will accomplish this as it is only a matter how fine the final stage is.
Doing a side by side would be easier and more quantitative by putting two empty glass tanks side by side and running the different filter setups on each while adding measured amounts of ammonia, tracking the cycle setup timeline and testing the biofiltration capacities after a period of time. I actually expect that this would not necessarily prove or dis-prove one media over another but show that the media choice probably makes no difference as we have this misconception of how much biofilm surface area is really needed in the first place, and probably by some factor rather than some margin.
I would suggest that if particulate is of no concern for this test and that a third tank with an empty filter would be as effective as the other two... so my point would be not to waste money on fancy media. Sponges, floss and pillow stuffing are just as effective as they are also not a real factor in the biofilm development anyway.
Interesting point about caught waste breaking down then falling through and going round, I never thought of that before. Yet more supporting evidence as to the importance of water changes.
BTW: how do you do that multiple quote thingy? I can only seem to get it in one big block.
Just copy and paste the quote start and end tags and put them in the body then enter your text between the end of one and the beginning of the other. You can even do multiple sources by "quoting" in the forum to a new post then copying the quote tags and text from that to put into another... that way it will reference the author in each quoted segment.
Jeff.
