discussion on biomedia...

[Magnum Man]

I've been doing this a long time, & given it much thought, & practice over the years... I doubt many would argue that more surface area is better on bio media sources... but I just saw some listed for sale, that I feel isn't a step in the right direction... I used to use porous lava rock, like you would use for a gas grill, or gas fireplace... & was happy with that for years, until I shut my tanks down ( about 20 years ago ) the lava rock was covered in bio slime... I'm sure all the holes were full of beneficial bacteria, however, from what I could see, the water could not get into the pores... in effect, the rocks could have just as well been smooth round river pebbles... when I was shutting down my tanks, sump systems were the rage ( mostly for salt water tanks ) & most of the media was like wiffle golf balls... you don't see that kind of media much in the hobby anymore... however a hollow ball full of larger holes ( large enough to not blind over, so water could flow through them ) has almost twice the surface area of a solid round ball ( or rock )... getting back into the hobby a year & a half ago... ceramic seems to have replaced the plastic biomedia... & I see Seachem offers a porous ceramic media for the filters, & I see similar, in both the Aquaclear 70's I have, as well as the Tidal 75's I have... I don't see any advantage or even less than those old lava rocks I used, as the pores are smaller, that what was in the lava... I've personally been using little ceramic tubes, with 1/4" center holes since I got back into the hobby...

so I'm a little curious why the wiffle golf balls fell from grace??? is it because they aren't natural ( the filter boxes are plastic )... there has to be al least twice the useable surface area for beneficial bacteria, as long as the holes are big enough they don't blind over...

I have a 250 gallon tank I'm hoping to set up this year, & I've been seriously looking at filling the filter chambers with the plastic wiffle golf balls

anyone want to dive in, with knowledge or practical experience...

 

[Uberhoust]

I believe the plastic biomedia like the wiffle balls do not have enough surface roughness to retain all their bacteria colonies when the biomedia is serviced. Due to flow issues seems like it is a bit of a packing problem, you want a large surface area but you also what good water flow.

My personal experience is that the hollow cylinder ceramic media work well. You get good water flow though a space packed full of media, there is enough surface roughness so the colonies are not easily sluffed off. I use some round ball ceramic media as well but I find the hollow cylinders seem to keep the flow better.

I think vesicular lava would work well, but to prevent tight packing of the media you would want to make sure that most of the stones are the same size, so that the smaller stones do not fill the voids between the larger ones. In general, I would expect your biomedia overall to work better if the media particles are of similar size otherwise maintaining high flow through the media might be difficult as it settles.

Just my thoughts no research.

 

[Magnum Man]

I could be wrong, but I think the bacteria has adhesion, as it's also on the glass, and all the tanks surfaces... I would suspect you are correct on trying to have similar sizes for flow... also golf ball size would likely be too big to get maximum efficiency from a typical hang on back filter... but a bio media of similar construction but of a smaller size 3/4 inch diameter might be nice???

 

[10 Tanks]

Hello Magnum. Since beneficial bacteria grows on all surfaces inside the tank, I question the need for any type of filter media. I stopped using mechanical filters and just increased my water changes to half every few days to a week. I'm supplementing the water change routine and use the Chinese Evergreen to use the nitrogen produced by the fish. The combination has resulted in nitrogen levels below 20 ppm when I tested the tank water one time a long time ago. With such an aggressive water change routine, I doubt that nitrogen would even register on a test. My tanks have a lot of local rocks and driftwood, so there's plenty of surface area for bacteria. Over the years, I've certainly saved a lot of money on mechanical filtration and replacement media.

10

 

[Magnum Man]

plants do make a big difference... I can't help it, I like a lot of water flow, and most of my fish , he said currently ( catch the joke ) are river fish so they like the flow as well...

I've not been lazy, but I'm a couple water changes behind, because of refilling my 45 gallon ( used up all my RO water ) for a week...

but having the plants, & all that mechanical water movement... the fish are still looking good...

 

[Uberhoust]

I could be wrong, but I think the bacteria has adhesion, as it's also on the glass, and all the tanks surfaces

I believe you are right, but a simple wipe of a cloth over the glass will remove the majority of the colonies on the glass, whereas with a porous media even if roughly handled you have refuge spaces where removal of the colonies can be difficult. I don't service my filters much after going to the canisters and foam filters but when I used the aquaclears I was often rinsing the biomedia.

 

[10 Tanks]

Hey Magnum. So, tell me, why the Reverse Osmosis water? Is your tap water too high in minerals. What have missed in your posts that you need RO water?

10

 

[Magnum Man]

we are in Southern MN and have some of the hardest water in the country... a long time ago, the house was hooked up to a whole house softener, no well water lines in the house, or big rusty stains in a week, in the sinks... so my only original option was house softened water, which was hugely alkaline... I recently added a saddle valve for a 1/4 inch poly line, before the softener, and ran that over to my aquariums, and RO unit... the RO unit was burning through the softener salt, & to add to tanks, like my cherry shrimp and live bearer tank

 

[TwoTankAmin]

I should have seen this thread sooner. The bio-film on the glass is not where the nitrifiers prefer to live, They are a somewhat photo-phobic and, on the glass, it puts them in light from both sides. The ammonia oxidizing Archaea are even more photo-phobic than the bacteria.

FEMS Microbiology Letters
Research Letter

Differential photoinhibition of bacterial and archaeal ammonia oxidation​

Stephanie N. Merbt, David A. Stahl, Emilio O. Casamayor, Eugènia Martí, Graeme W. Nicol, James I. Prosser
First published: 17 November 2011 | https://doi.org/10.1111/j.1574-6968.2011.02457.x |

Abstract​

Inhibition by light potentially influences the distribution of ammonia oxidizers in aquatic environments and is one explanation for nitrite maxima near the base of the euphotic zone of oceanic waters. Previous studies of photoinhibition have been restricted to bacterial ammonia oxidizers, rather than archaeal ammonia oxidizers, which dominate in marine environments. To compare the photoinhibition of bacterial and archaeal ammonia oxidizers, specific growth rates of two ammonia-oxidizing archaea (Nitrosopumilus maritimus and Nitrosotalea devanaterra) and bacteria (Nitrosomonas europaea and Nitrosospira multiformis) were determined at different light intensities under continuous illumination and light/dark cycles. All strains were inhibited by continuous illumination at the highest intensity (500 μE m−2 s−1). At lower light intensities, archaeal growth was much more photosensitive than bacterial growth, with greater inhibition at 60 μE m−2 s−1 than at 15 μE m−2 s−1, where bacteria were unaffected. Archaeal ammonia oxidizers were also more sensitive to cycles of 8-h light/16-h darkness at two light intensities (60 and 15 μE m−2 s−1) and, unlike bacterial strains, showed no evidence of recovery during dark phases. The findings provide evidence for niche differentiation in aquatic environments and reduce support for photoinhibition as an explanation of nitrite maxima in the ocean.
Differential photoinhibition

As far as I am concerned the best static media I know of is Poret (or similar) foam or a similar foam. And then it has be used in a decent volume as well. It will give one some level of denitrification given several months for it to become established. It will also proved a fair amount of mechanical filtration.

The are other life-forms living in the foam which will consume a decent amount of the organic waste being sucked into or through the foam. My clearest tanks are the one with Mattenfilters on them.

Maximal surface area for any mass requires that it be very porous. The more potential pathways though the labyrinth of pores, the better substrate it will be for the nitrification denitrification as well as "mechanical" waste handling.

I use Poret foam in my Aquaclears. in some canisters, as pre-filters and even as a tank divider which also turns out to make them become filters to some extent. I even use the 10 ppi foam to make my intake pre-filters,

I have use hang-ons. H.O.T.Magnums, Bio-wheels, Canisters, ATI sponges, powerheads with huge foam intakes, Poret cubefilters, Mattenfilters and heavily planted tanks. As far as I am concerned a well planted tank with a 3 inch deep substrate is one of the best filters there is. For a tank with no plants, the award goes to a Hamburg Mattenfilter.

Also, I pretty much pre-filter all of my intakes.

Any tank can benefit from some amount of substrate as the nitrifying bacteria will colonize about the top 1/2 - 3/4 of an inch, below that there is not enough oxygen for them unless it is supplied by plants which release it through their roots.

edited for typos

 

[Colin_T]

Sponges are the best filter media. They have excellent surface area for holding beneficial bacteria. They are cheap to buy, easy to clean, and last for years. They also trap gunk and remove it from the water column.

 

[GaryE]

I keep an eye out for a product I bought a sheet of at a marine store years ago - "Japanese filter matting". It's a compressed tangle of recycled plastic fibres - bright blue, ugly as sin and really effective. It cleans easily, and provides excellent bio-surface. It's available on Chinese sellers, and I see one Amazon.ca seller for it. For a long time you couldn't find it.

It's sold for pond filters.

I have it in all my powered filters - canisters and HOBs. Most of my fishroom is air driven, but this stuff is good. It is hellacious to cut, and will give you superbly muscled thumbs, but it's great stuff.

I have also used plastic scrubber pads from the dollar stores - the five to a pack multicoloured things. They provide a lot of surfaces, and can be cut open and modified.

I think a lot of good media isn't sold because good media doesn't need replacement. The push in the industry is for disposable filtration media that has to be bought again and again, so the filter becomes a consistent source of income. Hobbyists are less into fishkeeping, and sumps 'setter uppers" aren't as common as they used to be.

 

[Magnum Man]

I have no doubt, that the sponge, can hold up to more than it’s weight as a media… but as you guys brought up this old thread ( to my appreciation ) , I’m sitting here watching, in action, maybe something as good or better???

I think the biggest downfall of the sponge material, which is also why it works so well, is it’s capacity to hold solids, so eventually, it needs cleaning…

I’m sitting here this morning, drinking my caffeine, and watching a power head wiggle the fingers of a dense pothos root… I’m sure beneficial bacteria must grow on the surface of the roots, and this tank in front of me, has 2 dense root balls the size of footballs, each in the outward stream of a power head… each root ball, feeds a 10 - 20 foot vine, growing very aggressively, so the plant is acting as a mechanical filter, but the root ball, is also acting as a media that holds beneficial bacteria, as well…
As an experiment, I have a monstera vine, and a pothos vine, that are actually the filter elements in 2 big hang on tank filters, in a tank with a fair amount of bio load, and have not had to service those filters, in over a year, zero maintenance… I’ve been watching the flow, expecting to have to trim the roots, because of impeding the impeller, but in over a year, no service has been required, perhaps the movement had kept the root ball clear of those parts… but it would seem the natural filter component of an active, dense root ball, in combination with water flow, may filter, equal to sponge material, and require much less mechanical cleaning??? On this case, one of the best medias, may not be a traditional media

 

[Magnum Man]

@GaryE … by description, that sounds like the material they use for mats in humidifier’s???
I’ve seen them in wick styles, as well as shaped into wide belts, that rotate on wheels, that move them from the water resovour to in front of a fan, they are like woven fibers???

 

[GaryE]

Whatever works. Yesterday afternoon, I made 2 undergravel filters, because I have two tanks I want to run really shallow to meet the needs of some of my Gabon fish. They're copies of some homemade filters that came with tanks I bought second hand in 1990. I suddenly remembered those (I used one and threw the other 2 away, since undergravel was out of style) and decided to put some together. If they work they join the whatever works list...

Amazon.ca

 

[Magnum Man]

That is similar to what I envisioned, from your description... & I still have 2 tanks that use under gravel filters as well as HOB filters, & plants... they just seem to add a level of stability... but they do make the vacuuming of the substrate more important... or maybe just pull more solids there, so I suspect they would be better for rooted aquatic plants... even though, in my case the only aquatic plants in those 2 tanks, are Java Ferns, so I doubt they benefit much from the collection of solids in the substrate, for those plants...