External Filter Media

[Polish]

I have owned a Juwel 120liter fish tank for almost 4 years now and have been able to look after that no problem. But I will soon be getting a new tank (Fluval 190 corner tank) with an external filter. Now the problem I have is, my Juwel tank has an internal filter and I have never used an external filter before. With the internal filter I changed the filter media so I just have
2x pre-filter poly pads,
2x sponge coarse,
2x sponge fine.
I found this worked better than adding the carbon filter, as I was told this is only really used for removing medicines and making the water slightly softer, (which I don't need to do) and adding the nitrate sponge.

I was wondering are external filters the same? Should I replace the carbon for more biological filtration such as biomax? The external filter I will be using will be a Fluval 205 series Link!. Any help for the best type of media filtering system would be much appreciated. Thanks.

 

[waterdrop]

The knowledge you've gained about media will hold true no matter what type of water circulation mechanism is used in the filter design. The three main media categories: mechanical, chemical and biological still hold true. Most types of media overlap and can play more than one function but each media is optimal at one of the 3 functions generally.

Media that perform chemical functions usually are only needed for temporary periods to accomplish specific objectives. Carbon is a prime example of this. On average, it accomplishes as much mopping up of charged particles as it can do within 3 days of being put in and is then ready to be removed and thrown out. Its ideal job is this sort of charged chemical removal and it is a less than ideal biological media. As such, most of us remove it from a new filter before use and store it in our supply cabinets in case we need it. What it then gets used for is removal of medications after they have been in the tank their allotted time or removal of yellow tannins from woods or sometimes the odd organic odor of unknown origin. Zeolite is another example of chemical media that should only be used for special circumstances in most cases.

One of the main differences in an external filter is that you'll need to be aware of "priming" it to get the flow started. Many have automatic mechanisms for this but it is still good to understand it.

~~waterdrop~~

 

[Polish]

Ok thanks for the advice and I looked into priming for a few minutes. The filter comes with its own self-priming mechanism so I can easily use that. Thank you.

 

[waterdrop]

Even if they have so-called self-priming mechanisms, it's good to understand that if you maximize the water in the system before starting the priming process, you'll have less to overcome. So one good technique with externals is prior to applying any power to the pump just get the siphon going from the tank into the external cannister and give it a good long time to completely fill the cannister and settle some of the bubbles up so that you'll have less bubble removal after you apply the pump. After applying power and having it running completely through then gently lift the cannister a little bit and vibrate it a little at angles slightly off-axis from straight up and you may find that stray air bubbles will make their way out. If the bubbles are too big they can cause you to need to re-prime but it is better to do this while you are there than having it happen later when you've left.

~~waterdrop~~

 

[Polish]

Ok didn't know that thanks.

 

[mishka83]

Another useful thing to bear in mind is that you can help cycle your new tank more quickly if you put some of your used & dirty media from your old filter into the new.

I love the corner tanks, no spare corner here for one though!!