I like big filters and I can not lie

[TwoTankAmin]

What we call a filter does not filter anything, it is a machine that moves water and which houses media which in turn provides a home for the microorganisms which are actually the filter.

So to have a better filter one basically needs bigger and/or better quality media. My best filters are my Hamburg Matten filters. I power these mostly with air but I have also used small pumps as well. I get denitrification in my large foam filters. I use high quality, semi-rigid porosity controlled foam. This can also be used as filter media in almost any filter made. I even have one of my 3 canisters filled with only this foam. I have 3 identical canisters and the one with the quality foam needs to be cleaned about once every 3 - 4 years. I clean the other two with more conventional media (noodles, bio-media and floss) every 6 months.

It took me a number of years in the hobby to come to learning how filtration actually works. So what is it our filters actually do? Whether one has a hang-on, an internal, a canister , a sump etc. they all do the same things:
1. Circulate water.
2. Hold media.
3. Provide some incidental heating due to the motor.

The hardest thing for me to understand was about what we call mechanical filtration and media. What exactly does mechanical media remove? Most people will answer solid waste. But what exactly is solid waste? For the most part is is actually organic particles. And in nature these particles are food. Most "mechanical waste: in nature is actually consumed not trapped and thrown out. Bigger creatures eat bigger particles which become smaller and get eaten by even smaller creatures. In some case one creatures wase output is another creature's food. This is how the nitrogen cycle works.

Organics waste gets turned into ammonia which is consumed by bacteria or Archaea which in turn makes nitrite then cunsumed by other microorganisms and the result of that is nitrate. Under proper conditions this can be turned back into nitrogen by other microorganisms or consumed by bigger things like plants or algae etc.

All filters in our hobby have trade-offs. The most obvious one is size- the smaller a filter, the less media it can hold. However, the choice of media matters. Porosity and durability matter. The next consideration is actually one about which we rarely think and that is oxygenation. The nitrifiers are aerobic and need oxygen to function. However, the denitrifiers need the opposite, no oxygen. Most filtration only provides minimal denitrification, so in FW tanks we change water a lot in most cases to deal with nitrate.

All of the above factors into how effective any filtration might be. Oxygen is often the key. Out fish etc. all need to have adequate dissoled oxygen (DO) in the water to survive and to thrive. This also applies to the microorganisms doing the actual filtration. So let's consider DO.

The most common way DO levels are maintained in water is from the surface being agitated. This promotes the natural exchange of gasses between the water and the atmosphere. Most filtration devices will only get the amount of Oxygen which is already dissolve in the intake water. On the other hand, hang on filters are exposed to the air and can add some oxygen beyond what is in the intake water. Canisters (among other filters) cannot do this And this is the one potential drawback of them.

One of the benefits of a canister is its size. But this can also be a drawback when it comes to inadequate DO in the intake water. Insufficient oxygen means that less bacteria can survive. What this means is that we need to be sure the DO levels in our tanks ae adequate. This is one of the advantages of a sump. It is open to the air and as the water moves through the sump it is able to add oxygen. The same is true for hang on filters.

Of course one of the best filters we can have is a planted tanks where the plants are rooted in a decent depth of substrate. The plants eat ammonia (as ammonium) they do not create nitrite or nitrate, in fact they may consume nitrate. They also host nitrifying organisms on their surfaces. Some plant even transport oxygen down to their roots which are often in anaerobic zones. They release the O which makes it possible for nitrifiers to colonize and go to work. This in turn fosters nearby zones where denitrifiers colonize and consume the nitrate then being created.

If all of this is something that interests you, have a read here: Aquarium Biofiltration And for plants fostering nitrifying and denitrifying bacteria, have a read here Aquatic Plants and the Nitrogen Cycle

edited to fix typos

 

[10 Tanks]

Hello. Whoa! That's a ton of information. Sorry, I didn't go through all of it. The best filtration is nothing more complicated than the large water change done every week. Nothing can replace it. Not all the mechanical gizmos, surface and bottom plants or anything else. Just change most of the tank water weekly, no excuses and your reward will be healthy fish and a lot more money in your pocket for that special tank or fish you've been wanting.

10 Tanks (Now 11)

 

[Uberhoust]

This builds on @TwoTankAmin comments.

Mechanical filtration is important, as mentioned in previous posts a lot of it is for the removal of un-eaten food, but it also filters out a lot of inorganic sediments. With a new filter and tank disturbing the substrate causes far more turbidity for longer than if the same disturbance in a tank with a filter that has filter with an established foam filter or even just a bio substrate filter. Particles are trapped mostly by the biofilm that grows on everything in an establish tank but is made more effective if the biofilm is growing on a filter sponge that has a very large surface area. This is also why prefilters, intank foam filters, etc. are often a good idea because the coarse food bits get trapped in a location where the fish, and others, can feed on the organic material. Its also why we often go through a short green water phase in a new tank, the biofilm hasn't been established and the fine particulates provide a substrate for free floating algae. The typical coarse strainers on a lot of filter intakes are simply taking usable waste and putting it where the fish and and other animals cannot get to it.

Oxygen is necessary for the conversion from Ammonia to Nitrate. Oxygenation is dependent on the exposed surface and the partial pressures of the O2 in the water and the O2 in the atmosphere. Filters provide water movement which puts new water that is not at equilibrium in regards to Dissolved 02 at the surface. This water movement means that the water stays at the DO equilibrum level without zones of depletion in the water column. Without this water movement the same process will be occurring but at a much slower rate based more on diffusion of the DO through the water column. Additionally, the filter passes much more water and hence DO past the bacteria cultures in the foam or bio media than would normally occur allowing the system to have a larger culture of bacteria and a higher bio load than would be available without the filter. It would be interesting to calculate the total surface area of the bubbles of an airstone and see how that would compare with the surface area of an aquarium for oxygen exchange.

It is my opinion, from some research I have done, that the biological conversion of nitrates to N2 is not feasible in an enclosed aquarium system. As mentioned in other posts control of the nitrate waste in the system is best accomplished through water changes (nothing to do with the filter), but in a heavily planted tank it can also be accomplished with the plants using the nitrogen to provide nutrients for their growth. Removal of dead plant leaves, and pruning of the aquarium plants I believe would be a more efficient way of removing nitrates and nitrogen from the system than bacteriological means though I don't have a lot of research to support this point of view. Emergent plants would be even better as they are not as carbon limited in their growth and hence need more nitrogen for their tissues.

Overall, the larger the filter the more oxygenate water can be passed by whatever culture media is used for the bacteria and the more creatures can live in the tank (only considering DO and nitrogen wastes). Limitations would only be if the DO consumption by the organisms in the tank exceed the rate at which oxygen can be absorbed at the surface, a bit of a case against canister filters, but I haven't heard of any cases where normal stocking comes anywhere near exceeding the rate of oxygen exchange of the water except in exceptional conditions.

 

[anewbie]

Aquael for me has to be one of the most exciting brands in our hobby at the moment, everything they are doing just seems to be great - love their new tank ranges.

I came across this one the other day which looks like its not fully launched yet but just looks awesome

https://www.aquael.com/products/aquaristics-us/aquaristics-us/filtr-hypermax-4500/

Its more powerful than a Fluval FX6, its got a pre filter!!! So no more taking the whole thing apart for basic maintenance like an FX and it looks like it has regular hose size pipes which means you can probably upgrade your inlet/outlet to steel without an issue (though I know not everyone is into it).

Does anyone here have any one of their existing external filters? Either the Ultra or the Ultra Max? Would be interested to hear how people find them.

Wills

Seems to be available in some locations for 350 euro; i wouldn't judge a product by the specs; i'd like to see how easy it is to clean and maintain as well as longevity and that ignores comparing specs to acutal performance. Don't get me wrong i'm not in love with the fx6 but it takes more than specs to find a decent replacement.

 

[TwoTankAmin]

Nitrate removal is possible in Mattenfilters. It is accomplished by facultative bacteria. They can use oxygen when it is here but when it is not, they can use nitrate. With an established Mattenfilter you get these bacteria colonizing. Now this is where the concept gets a bit tricky to understand.

The foam in a Mattenfilter permits an incredible number of potential paths that a molecule of water can travel between where it enters the foam and where it may exit. As that molecule travels through the foam what it holds changes. If it goes into the biofilm it might donate oxygen the bacteria or Archaea or other aerobic organisms. At some point that molecule has all the oxygen it is carrying used up by the bacteria and it now contains nitrate. When it reaches the facultative bacteria which lie along the pathway it travels, they will use that nitrate and the result will be N2 gas which works its way out of the system into the atmosphere.

Nitrate Respiration: Here, in place of oxygen, nitrate is utilized as an energetically favorable electron acceptor in the electron transport chain. Nitrate is reduced to nitrite that is eventually converted to molecular Nitrogen, N2, (i.e. NO and N2O) via denitrification process. Or, it may be converted to ammonium by a process known as respiratory nitrite ammonification.

from https://www.biologyonline.com/dictionary/facultative-anaerobe

Any molecules which travels that specific pathway through the foam will have its nitrate used. Much of the time the water will move though places where not all of the O may be used while in other places it will be. For there to be "serious" denitrification in a Hamburg Matten filter it needs to be mature and well established.

I also get a similar results from the Poret foam cubefilters. In my 125 gal I have 3 5x5x5" cubefilters and a 5x5x10" tower block. Stacked that is 5 x 5 x 25 = 625 cubic inches of 20 ppi foam. But my Mattenfilters are in 33L. One tank has a 3" thick foam, another tank has a 2" at either end and a third has a 2" foam and a 5x5x5" cubefilter. Finally, I have a 4th one with four 5x5x5" inch. The tanks all have sand substrate plus wood, rocks and caves. The lights are only on when I am working in the tanks, so no visible algae.

I do not remember the last time I used a nitrate test. The last two expired almost unused.

 

[anewbie]

You can also get nitrate eating bacteria in the substrate; I had a 20 long where the nitrate stayed near 0 for a year - since it was heavily populated and the numbers just didn't match the two 29 next to it - i spent month trying to figure out what was happening. I did pick up a more sensitive nitrate test kit and the nitrate was hovering around in the 1 to 3 range (way too low for api liquid test). However it wasn't clear to me if not having nitrate due to this effect was less or more beneficial than my other aquariums. Plants did grow well in this aquarium and i did dose it regularly with fertilizer (more so than my 29 since the nitrate level was so low).

 

[seangee]

You can also get nitrate eating bacteria in the substrate; I had a 20 long where the nitrate stayed near 0 for a year - since it was heavily populated and the numbers just didn't match the two 29 next to it - i spent month trying to figure out what was happening. I did pick up a more sensitive nitrate test kit and the nitrate was hovering around in the 1 to 3 range (way too low for api liquid test). However it wasn't clear to me if not having nitrate due to this effect was less or more beneficial than my other aquariums. Plants did grow well in this aquarium and i did dose it regularly with fertilizer (more so than my 29 since the nitrate level was so low).

The more likely explanation is that the plants take care of the ammonia (without creating nitrite or nitrate) and the filter is doing nothing to contribute to denitrification. The tank in my signature never has detectable nitrate, but I also know that when I tried to seed another tank with the filter media from this tank it did not work. The bacteria simply has no chance because the plants suck the ammonia out of the water before it gets to the filter.

 

[anewbie]

The more likely explanation is that the plants take care of the ammonia (without creating nitrite or nitrate) and the filter is doing nothing to contribute to denitrification. The tank in my signature never has detectable nitrate, but I also know that when I tried to seed another tank with the filter media from this tank it did not work. The bacteria simply has no chance because the plants suck the ammonia out of the water before it gets to the filter.

Naw; first i don't see what the 'filter' has to do with my comment; esp given that you don't know what kind of filter it had. The 20 long had sponge filters; the 2 29's had matten filter (just a larger sponge with more flow); all three aquarium had lots of plants - the 29s had as much or more plants than the 20 long.... Actually the 20 long also had a turtle 'cansiter' fillter on it - you can look it up - it is a fairly weak canister filter sold by zoo med; it was rated as being fine without gravity feed since the 20 long was on the floor.