Warning Cut an Paste Ahead...
"I'm sure there are MANY opinions on this subject as well as others...ie:water changes,DSB,CC,UV,Ozone,MHvsPCvsVHO,etc.
This is what works for me and is expressed only as an option/opinion
I believe there are three "separate" types of filtration...Biological, Mechanical,and Chemical...and they should be treated and maintained as "independent" systems...A change in one should NOT affect the others...
Biological Filtration:The main factor in biological filtration is the ability of bacteria to convert waste to ammonia to nitrite to nitrate to nitrogen...this is brought about by large quantities of bacteria which in turn need large amount of "surface" area to grow...
This "surface area" can consist of many "media"...The most popular and natural being Live Sand/Live Rock..., as well as "bio balls" in a wet/dry,Crushed Coral beds, and even the "Sponges" on PH pre- filters, and on/in a "bag" of carbon or other "chemical media" that hasn't been changed often enough.
Mechanical Filtration: The main factor in mechanical filtration is its ability to remove "organic particles" BEFORE they have a chance to decompose and increase the "bio load" (Which is why they need to be cleaned often and on a regular basis)as well as floating particles and "polish" the water...
Most common "mechanical" filters are sponges and "filter floss" in canister and "hang on back filters and pre-filter sponges on PHs and at the top of wet/drys...Skimmers also fall under the category of mechanical filtration by means of removing organic compounds through non-biological action...
A well stocked and "balanced" tank should have enough surface area in the LR/LS that supplemental area should not be needed to maintain a healthy tank...
Therefore "Mechanical" filters can and should be cleaned often and washed out in FRESH water, removing organic materials prior to decomposition and minimizing the build up of bacteria on them.
Bio-balls in a wet/dry should be treated differently as they ARE part of the biological surface area and should be cleaned only a part at a time and rinsed only in SALTWATER preserving the bacteria growing on them.
Cleaning filters/sponges often enough (once a week/every two weeks) will prevent EXCESS build up and decomposition of material and the resultant SLOP flowing through the tank when you finally DO get around to clean them...
Allowing too long a time between cleanings also allows bacteria to propagate on them and will then cause an "imbalance" in the biological aspect of your filtration system when you DO get around to cleaning them.
I have found that regular cleaning of mechanical filtration has allowed to keep a well stocked Aggressive Tank (notoriously messy eaters) at a NitrAte level under 20ppm (4 on a n-no3 test)with the addition of a shallow sand bed/LR and good sized "fuge" with Macros.
As a side note...some will say mechanical filters such as sponges can remove beneficial organisms such as planktonic larvae, zoo plankton, and pods which are desired in a REEF tank...with this I do not disagree...
However, it should also should be noted that each individual tank/system is different and each system should be accessed for both the possible benefits/negatives of cleaner water vs. a more natural food supply."
This is a cut and paste from an earlier post on mechanical filtration...
As a new tank the next question is, What are you planning on setting the tank up with...besides fish I mean...
You will need some sort of "substrate" on the bottom...and a sand bed and a couple pieces of LR will be a start toward establishing the "biological" portion of your filtration "system"...Not a strong point of "canister" type filters...
And will much easier to take care of in the long run than a Crushed Coral bed...
Keep asking questions on this board ..and READ a good book or two on the subject of filtration, BEFORE making any purchases...
I would suggest "the New Marine Aquarium" by Michael S. Paletta to start and another...I believe it's called... "The Conscientious Marine Aquariest...? Some one else will have to site the author...