Bi-Weekly Discussion of the Week: Mechanical filters!

[Geoff]

Let us talk about both canister and HOB filters. Do these have a use in a reef system?

G~

[Phishnoob]

After reading a bunch of posts I would say no. With a 2 inch sand bed I put an army of nassarius snails in there working with my spotted sweetlip to churn the gravel and hang a bag full of floss with a bag of carbon inside over the tank return in the sump.

Throwing the whole bag away and cleaning the gravel at least twice a month seems to work for me. After only six months I am too new to know much, but it is almost a universal opinion that a mechanical filter with media is a future phosphate factory.

[kwjones]

They're great for water polishing. I don't think they're ever a problem if you can keep them clean.

[tims]

i agree with Kevin , also good if you can not use a sump. i leave my canaster hooked up and running, mostly as a current flow device.. but if i need to polish ..hey it works great...
from everything in the threads and in the books, i do not think they are the thing to use in a reef tank, but are a good to have back up if needed..IMO

[kwjones]

Once I finally get the bb tank set up, I'll just be using my canister filter for vaccuming the tank and the sump a couple of times a week. For now, it's just extra water movement in the tank.

My big problem was I never changed the filter media as often as I should have, so I had excess nutrients. Now I run it empty.

[Geoff]

what makes them problematic in a reef system?

G~

[tims]

problematic to the system..umm. i almost think of it as a closed loop system( filter),as kevin said. changeing on a normal schedule is something i think a lot of us have or did have. IMO they can bound up quite fast.. meaning they need to be cleaned often. then you also have the tubing itself. over time that too gets ..gunk ( lack of of a better word) in it.once i finish making the 140 gallon tank and switch to a sump, i will only keep it ot use as a polisher or maybe for just water movement if i need it... i can not belive i just said that.. i remember when they first came out and were the biggest and badest thing for filters

[SouthernReefer]

diatom filters are a great filter to have in those cases of emergency like a tank crash. it has the ability to strip clean a tank's water column, or remove ich or any pathogen that's freefloating down to 1 or 2 micron in size. the only down to side to these filters is changing out the media, that gets quite messy.

[Geoff]

are there any other uses for mechanical filters?

think nano.

G~

[SPC]

IMO we need to get detritus out of our reef tanks on a regular basis. If a HOB or canister will do this for your tank then I think they should be used. As already mentioned by others, one must be willing to devote the time needed to clean them for them to be most effective.

I use a Hot Magnum with micron cartridge once a week to siphon detritus out of my sump. I also storm my main tank once a week with a powerhead and catch what I can with batting located in the sump.

The other concern I have heard about the use of mechanical filtration is that too many benificial organisms will be removed from the system.
Steve

[kwjones]

Originally posted by Geoff

think nano.

G~

They make a pretty decent home to all sorts of bacteria. I think I've read about a few people taking those larger Hagen Aquaclear filters and using for a HOB refugium.

Kevin

[Geoff]

Originally posted by SPC

The other concern I have heard about the use of mechanical filtration is that too many benificial organisms will be removed from the system.
Steve

what beneficial organisms? we know that pods and tunicates love to live in those sponges that come in those filters, but what do they add to the whole system?

Steve, i am not trying to be snotty.

i use intake sponges on all of my CLS's just for the reasons SPC has stated. i also remove and clean them on a weekly basis. this is great at removing the detritus, but it is still not often enough to remove most the phosphates before they are released back into the water column.

G~

[SPC]

Originally posted by Geoff
what beneficial organisms? we know that pods and tunicates love to live in those sponges that come in those filters, but what do they add to the whole system?

Good morning Geoff,

Nothing IMO unless one keeps animals that are dependent feeding on them for nutrition (mandarins for example).

Some would argue however that pods are an excellent detrivore and are a key part of the food chain in our systems. I don't subscribe to this thinking though, they actually only add to the bioload of a tank and serve no real purpose IMO.

Steve

[Geoff]

in that case would they just be another good way to export nutrients? pod culling.

G~

[billpa]

I have an AC300 on my reef tank that I use constantly whether empty or filled depending on whats going on...it will eventually be retroed with a baffle and used a refugium for my 7 gallon starphire nano that I am building Yes they can trap crap very quickly...thats why you have to regularly maintain them when they are carrying media...overall not the best means of filtration but it does fill a niche that other methods cannot...for us sumpless folk that is

billpa