I am sorry for the long post, but I hope it expalins how and why I do things as I do. As always, it I how I do things. It is by no means the only way to do them but I have found it works very well for me. All of us must decide what works best for them as long as our goals are the same- to keep our fish healthy and living longer lives than they might in the wild.
I have never done a SW tank and never will, I hate salt water itself, not the fish etc. but salty water itself. I have not been in the ocean in almost 6o years. I like the shore but I never go to the beach ot into the water. I really dislike the feeling when the water evaporates and the salt remains. I hate the sand getting into everything. But I like the night life on the shore and, having reached the age of being a "dirty old man" I enjoy watching the gals in bikinis. When I was younger I did to ocean and even did some scuba dibing in the Bahamas and in Acapulco Bay. I also gave up hatching BBS as the bubbling jug in which I did it put out a salt water mist which messed up everything around it.
I am also lazy. By this I mean I hate having to do things inefficiently. I am a big believer in two things:
1. Occam's razor is a problem-solving principle stating that when presented with competing explanations for the same phenomenon, you should select the one that requires the fewest assumptions. It is a rule of thumb to "shave away" unnecessary complexities rather than an absolute, unshakeable law.
The Core Idea
Attributed to the 14th-century English philosopher and Franciscan friar William of Ockham (often spelled Ockham), the principle is summarized in Latin as pluralitas non est ponenda sine necessitate, or "plurality should not be posited without necessity".
Put simply: the explanation with the fewest moving parts and untested theories is usually the best starting point.
2. T
he KISS theory--> Keep it simple, stupid!
As folks here know I am a big fan of Poret foam because of its physical properties. The plecos I have worked with for years when young do not do well with nitrates. However, in my tanks with Poret Matten Filters or multiple Poret cubefilters, I do not worry about nitrates because my media also does denitrification.
The bacteria for doing this are called facultative. They are able to function both aerobically and anaerobically. When the water which reached them has passed though areas of nitrifying bacteria as well as other hetertrophic oxygen using bacteria, what emerges is water with no oxyen but which contains nitrate. Whem that happens thee facultative bacreria cu=hange what they do and they use the nitrate, The result is N gas.
What makes this possible is the structure of the sort of foam engineers to be more righ and more porous and controlled as to the porosity. Consider a sheet of Poret type foam 2 or 3 inches thick and which completely fills a section of a tank from front to back and from the bottom glass the just above the surface of the water. There are an incredible number of pathways water can take to get though the foam.
As the microorganisms create the EPS which coats the pores and inside which the microorganisms live, it is possible that in some number of the potential pathways the nitrifiers will use all the oxygen and will produce nitrate. As the nitrate filled water moves further along it encounters the facultative bacteria which then use that nitrate. And the result is one has the complete nitrogen cycle in their media.
However, it takes more time for the the facultative bacteria to establish and then the time for it all to fall into place. What makes this possible is the massive size of the foam in terms of its internal structure combined with the semi-riigid natur of the foam which ha;d maintain the structure.
Because the amount of media is so massive, it becomes a lot harder for the foam to become clogged and harder to be degraded. I do not squeeze out Portet, I swish it. I will tap a cube filter gently against the sides and bttom of the bucket and swish it. This works well. Here is how Dr. Tanner suggest one clean Poret sheets:
The easiest way to rinse your Poret ® foam sheets is outside in the yard or driveway using a garden hose. Simply bang the sheet flat on the ground several times (Note: I recommend not wearing your best outfit doing this) to shake out the filter sludge, then rinse with the hose. Repeat until the water coming out is relatively clean. Don’t overdo it. Sufficient microorganisms will survive this procedure to quickly re-establish the biology of the filter. It does not matter if you use cold or chlorine-treated water! The often repeated notion that this process would kill all the filter organisms is nonsense, because the residual chlorine concentration in drinking water is too low to kill them all. The microorganisms are quite well-protected in the slime of the biofilm.
When I was first starting to use Poret and a few Matten I asked Dr. Tanner how I would know I needed to clean it. His answer was simple- when the water level behind the sheet was lower than what was on the tank side, it was time to clean it. Unfortunately, with the cubefilters this clue is not possible. When all my foam filters were ATI, I rinsed them weekly. When I changed them to Poret, this became monthly.
I also filled my 3rd canister with all Poret. Again I asked Dr. tanner when to clean it. He said when the return flow to the tank had clearly slowed. I have recently leaned that filter for only the second time in over 10 years. However, I also have to admit that the 75 gal. tank it is on also has an AquaClear 300 gph (70) as well as being heavily planted. It has a single, regular output 4 foot LED type fluorescet style bulb.
One last observation her. Over time what one sees behind a Mattenfilter is best desribed as sedimant- very fine brown stuff. It is not the bacteria but the remains of the mechanical waste that has made the journey through the foam. What it took me some time to learn was that most of what is called mechanical waste is organic. In nature it is degraded by a series over ever smaller organisms which cone parts of it. But the big difference between what happens in nature v.s. intanks is the presence of larger organisms which are consuming and and shrinking the particles. Here is how Dr. Tanner explains things.
Eukaryota: the pore space in soils is full of organisms, some are sizeable such as earthworms and various insects, others are very small such as mites. Fungi are somewhere in the middle, since individual hyphae are tiny (in the micron range), while the whole colony can cover several square miles. Many of these organisms are summarized as detritivores, detritus feeders, or saprophages. They start the decomposition of organics by eating leaves, dead animals, excrements, etc. Their waste in turn is eaten by ever smaller organisms until we reach the true saprotrophs, which digest waste and organic matter by extracellular digestion (fungi but also bacteria and archaea). Saprotrophs release enzymes that break down matter and then absorb its components such as amino- and fatty acids, sugars, etc.
What does that mean for aquarium biofiltration?
Water filtration is teamwork by the members of the substrate microbial community from all domains of life. This is an important conclusion, both for freshwater and marine habitats. The different players form a food web, where most organisms cannot exist alone but are interdependent. The microbial community varies greatly depending on the availability of foods, pore sizes, and substrates.
And all of the above helps with my being "lazy." My filtration takes a lot less time to maintain because if this. It may xost me more up front but in the long run it lasts longer worked better and saves me a lot of time. I do not remember the last time I used a nitrate test kit. I almost never use a nitrite kit either unless I see fish gasping at the surface which is very very rare.
