Wet/Dry filters (N.B. POLKA)

[clayton]

Heres some notes on the theory behing wet/dry filters (especialy for Polka).
All a biological filter is, is a place for bacteria to live. The bacteria eat the animal waste (basicly). Whether they live in the gravel of your U/G or your canister filter or your wet/dry, they are all the same. Three main things govern the amount of bacteria that will colonise: 1)the amount of food available. 2)the surface area available to live on. 3)the amount of oxygen available.
It is often the amount of oxygen available that is the limiting factor.
In a wet/dry filter, the water is broken up into drops or trickles that fall down over a filter medium. The filter medium is not submerged in water. This means that there is far more oxygen available to the bacteria as the water flows over them. The filter medium used is usualy some form of spiked, plastic balls, although many things can be used - 'Stickle Bricks', hair curlers etc. The idea is to split the water into the smallest drops possible and slow it down as much as possible as it passes over the 'dry' part of the filter. Research has shown that 10 times the number of bacteria can colonise on a 'dry' filter medium as could if it were submerged.
These things are easy to make in a small seperate tank that sits under your main tank. The water syphons out of the tank, through the filter and is then pumped back up into the tank. See Martin Moe's "Marine Systems and Maintenance" for easy to follow directions.
The other advantage of wet/dry filters is that you can try to incorporate Gaseous Exchange Filters, but thats another kettle of fish............

 

[polka]

Thank you Clayton, you have given me a lot of food for thought! I understand the workings now and I do realize this would be a better system, however, am I doing any harm by waiting to save my pennies. Are there any warning signs that my u/g isn't working properly? So far everything seems to be working well. Does the filter system dictate how many friends I can keep?

 

[dennish]

What about the bio-wheels? How do they compare to the traditional trickle systems?

 

[mainejo1]

I have a bio-wheel on my 30gal., and I am happy with it. I have learned it does best if I change the cartridges once a month, and the loose carbon every 6 weeks AND rinse the filters inbetween with salt water from your tank. However, I have a 90 gal system that has a trickle type filter with bio-balls, and from what I am reading and observing, it is a great system. There is an incredible amount of surface area on each bio-ball, great areas for bacteria to live. Also, it is great having all the equipment under the tank, out of the way. The protein skimmer, heater are down there too.

 

[fishgirl]

I have a bio-wheel on my 30gallon, too!

 

[porkypuffer]

CLAYTON, IF YOU USED A POWERHEAD IN THE AQUARIUM TO PUMP WATER THROUGH A CANISTER FILTER AND OPENED THE AIR INLET ON THE POWERHEAD TO SUPPLY THE CANISTER WITH AIR AS WELL, HOW WELL WOULD IT WORK AS FAR AS SUPPLING A LARGE AMOUNT OF OXYGEN TO THE BIOLOGICAL FILTER?

 

[clayton]

Originally posted by PORKYPUFFER:
CLAYTON, IF YOU USED A POWERHEAD IN THE AQUARIUM TO PUMP WATER THROUGH A CANISTER FILTER AND OPENED THE AIR INLET ON THE POWERHEAD TO SUPPLY THE CANISTER WITH AIR AS WELL, HOW WELL WOULD IT WORK AS FAR AS SUPPLING A LARGE AMOUNT OF OXYGEN TO THE BIOLOGICAL FILTER?
Now theres a good question!!! I have never thought of doing this before but it may work very well. Check a couple of things first though: If the canister filter is actualy running and not just the powerhead pushing the water through then you may have a problem in that the air bubbles may collect around the canisters inpeller and stop it working (the powerhead may still push the water through fast enough though).
You would have to ensure that the bubbles from the powerhead enter the canister at the bottom and then pass up through the filter medium and out of the top otherwise it won't make much difference. The effectiveness would also depend on how saturated with oxygen your water already is. How much aeration is there in the tank?
If the caniter filter is the only filtration on your tank then be very carefull as if it goes temporarily wrong you may lose all your bacteria! Also if you do decide to try this make sure you do it quickly as all the time that the filter is off you are suffocating the bacteria.
If you can get the mechanics right then this method would certainly increase the availably oxygen (provided the water is not already saturated) to the bacteria, and provided that food and space is not limited you would probably increase the numbers of bacteria present in your filter.
It's a good idea! Ask a few other people their opinion and let me know how it goes.

 

[porkypuffer]

THIS IS AN IDEA I HAVE SHOULD MY IMPELLER BREAK IN MY CANISTER OR EVEN MAKE MY OWN CANISTER FILTER WITH A 6" PVC PIPE, INLET ON THE BOTTOM, OUTLET ON TOP AND FULL OF BIO-BALLS OR BIO-STARS. PUT A FOAM FILTER ON THE INLET OF THE POWERHEAD FOR A PREFILTER.