agd@homxb.UUCP (A.DEACON) (12/22/87)
In article <193@bacchus.DEC.COM>, reid@decwrl.dec.com (Brian Reid) writes: > . . . > > I am puzzled why it is not possible to set up outboard gravel filters. It > seems to me that as long as the water flows through bacteria colonies in the > gravel, it shouldn't matter whether the gravel is at the bottom of the tank > or off in another room. Why couldn't you have a circulating pump that drew > water out of the marine tank, pumped it through a large bank of gravel beds > that was kept nearby, and then pumped it back into the aquarium? > > Perhaps the answer is that there are other substances that are more efficient > than gravel when used outboard, such as polyester floss. Perhaps these > "Bio-balls" things, that I read about but don't quite comprehend, are a > gravel substitute for forming bacteria colonies on outboard filters. > Can somebody enlighten me? I would guess that posting your answer would be > better than mailing it, because I can't imagine I'm the only one who wonders > about these things. > > Brian Reid This is the principle behind the wet/dry and trickle filters that have been discussed here recently. Bio-Balls happen to be the media produced by Dupla to accomplish the "gravel" part of the system. The system provides oxygen saturation and improved filter volume/ tank volume to allow for higher tank populations than with other filter concepts. Art Deacon
dalka@ihlpg.ATT.COM (Ken Dalka) (12/23/87)
> > This is the principle behind the wet/dry and trickle filters > that have been discussed here recently. Bio-Balls happen to > be the media produced by Dupla to accomplish the "gravel" > part of the system. The system provides oxygen saturation > and improved filter volume/ tank volume to allow for higher > tank populations than with other filter concepts. I have a standard gravel filter with power head and a standard outside filter (aquaclear 1200) on my marine tank. I'm planning on replacing the outside filter with something better but haven't made up my mind just yet as to what. Ive been thinking about these wet/dry filters but the cheapest one I can find is about $200. I guess the first question is: Are there any for closer to $100 that are any good? This would be more in line with what I want to spend. Failing that, I was thinking maybe I could pick up a canister filter (I'm pretty happy with the Hagen Fluval I have on my freshwater tank) and try using some of the same media recommended for dry/wet systems. If I set up a good colony of bacteria in the canister filter, what would I not have that the dry/wet system gives me? The dry/wet systems I've seen have a protein skimmer but I think I could do without that so long as I kept up my regular water changes? right? wrong? By the way, Ive gotten by with my current system for 5 months on a 38 gallon tank with a somewhat light load (4 small fish, crab, shrinp, starfish). As a side note, I asked my local store about bioballs and they said they were Ok but recommended using hagen fluval or eheim prefilter media instead (The ceramic cylinders). They said they were just as good because the ceramics are somewhat porous and hold as much bacteria as the bioballs. Anybody got a recommendation for better material? -- Ken Dalka (Bell Labs) ihnp4!ihlpg!dalka IE 2F-518 (312) 416-7437
andre@nrc-ut.UUCP (Andre' Hut) (12/23/87)
In article <193@bacchus.DEC.COM> reid@decwrl.UUCP (Brian Reid) writes: >I've been doing more reading about marine aquariums, in some recent FAMA >issues and a few books. I get the clear picture that the consensus of modern >... >writers claim that the fish-holding capacity of your aquarium is limited by >the size of the gravel bed. >I am puzzled why it is not possible to set up outboard gravel filters. Indeed it is possible. The latest thing from the salt water world is a system called the "minireef". Part of that system is an exterior biological filter system. >It >seems to me that as long as the water flows through bacteria colonies in the >gravel, it shouldn't matter whether the gravel is at the bottom of the tank >or off in another room. Why couldn't you have a circulating pump that drew >water out of the marine tank, pumped it through a large bank of gravel beds >that was kept nearby, and then pumped it back into the aquarium? Great idea, nothing wrong with it. -- ----------------------------------------------------------------------------- sdcsvax-\ ihnp4-\ \ \ Andre' Hut sdcrdcf!psivax!nrcvax!nrc-ut!andre / / / hplabs--/ ucbvax!calma-/ / utah-gr!uplherc/ Network Research Corporation 923 Executive Park Dr. Suite C Salt Lake City, Utah 84117 -----------------------------------------------------------------------------
richard@gryphon.CTS.COM (Richard Sexton) (12/30/87)
(Our system had a foo. Found this article in 'junk' on 29-dec-87) In article <193@bacchus.DEC.COM> reid@decwrl.UUCP (Brian Reid) writes: > >I am puzzled why it is not possible to set up outboard gravel filters. It >seems to me that as long as the water flows through bacteria colonies in the >gravel, it shouldn't matter whether the gravel is at the bottom of the tank >or off in another room. Why couldn't you have a circulating pump that drew >water out of the marine tank, pumped it through a large bank of gravel beds >that was kept nearby, and then pumped it back into the aquarium? Quite doable. I remeber a British aquarium book, about 20 years old that showed how to make an 'algae' filter. You piped water out of the tank into a shallow tank, with the same width and bredth as the original tank. It was to contain pea sized gravel, and had strong lights over it. As they say (and say and say and say) in soc.singles: go for it. >Maybe I'm weird, but I've never liked the appearance of gravel beds. My >freshwater aquarium doesn't have any gravel at all, and it has done just fine >for years. With no gravel in the tank there is no danger of anaerobic pockets >forming under it, and cleaning the bottom is a snap. There is a nice colony >of bacteria in a sponge in the power filter. Not wierd at all. Gravel has its place. I have one tank that has a 3 - 4" layer of gravel, lots of plants, and is essentially a decorative tank. My other tanks are for raising fish, and get lots of food, and have the water changed more frequently. They have no gravel for the reasons you describe above. The plants are in clay flowerpots. "no worries". >Brian Reid -- Its too dark to put my keys in Santa Fe, or something like that. richard@gryphon.CTS.COM
patti@bucket.UUCP (Patti Beadles) (01/04/88)
In article <193@bacchus.DEC.COM> reid@decwrl.UUCP (Brian Reid) writes: > >I am puzzled why it is not possible to set up outboard gravel filters. It is. The idea is that you have to filter the water through whatever it is you're using. This material develops a colony of nitrifying bacteria on the exposed surfaces, and helps keep the nasty stuff out of your aquarium. If you've been following the "Dutch Minireef" information in FAMA, you can see that one of the main principles is an external biological filter with large surface area. >Perhaps the answer is that there are other substances that are more efficient >than gravel when used outboard, such as polyester floss. Perhaps these >"Bio-balls" things, that I read about but don't quite comprehend, are a >gravel substitute for forming bacteria colonies on outboard filters. Bio-balls are small (1" diameter) balls that have "prongs" all over them. Thus, they have a very large surface area for their volume. By putting them in an external trickle filter (where water drips over them instead of having them completely submerged) you get a high capacity for organic waste breakdown, and a high dissolved oxygen content. Youu can also use them in an external canister filter. >Brian Reid -- ************************************************************************** * The opinions expressed above are a figment of your imagination. * * ...tektronix!teksce!bucket!patti Patti Beadles to non-net types. * **************************************************************************