New filter advice

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Aquarium Advice Addict
Nov 2, 2011
Hi ive just bought myself an external filter, ive only ever used internal ones but decided to buy something better
Now I have 2 internals in my tank and when I run my new one will it be ok to run the external with one internal? As I don't want 3 filters going. And will 4 weeks be long enough to seed the external
Your plan is fine, but every time you remove a filter your cycle will have to catch up.

Lets say each internal filter is doing half the work. When you remove one of them, you will only be half cycled. After 4 weeks your canister will be seeded, but now your internal filter and canister are each doing half the work, and again after removing the last internal filter you will only be half cycled, and it might take a week or 2 for your cycle to fully catch up.

What i would do is to use filter material from the 1st internal filter you plan on removing in the new canister. Leave some space in the canister to then fill up with filter material from the 2nd internal filter when you finally remove that one. This should minimise the amount your cycle needs to catch up each time you remove one of the internals.

Edit: Canisters are often much bigger than internal filters. Can you remove all the filter material from the 2 internals and get all that in the new canister? You might be pretty close to an instant cycle if your canister is big enough and can then just remove the 2 internal filters. Squeeze out any sponges from the internals into the water too.
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I didn't even think about trying to squeeze my old media into the canister! Something I do immediately with my internals.
Thank you for that, I'll take a look tomorrow when I set it up.
I managed to put my media into my new canister
This is my first external and the flow isn't very strong, I'm not sure if this is ok or a problem
Its not a filter im familiar with, but flow rate is comparable with a Fluval 307 and capacity is comparable with the smaller 207. Id say neither a 207 or 307 is big enough to filter a 260 litre aquarium.

It says flowrate is 1500 litres per hour. Halve that for a real world situation. So 750 litres per hour, thats turning over less than 3x per hour. Target is usually 3 to 4x per hour.

I would be looking at 1kg of biomedia per 100 litres. So you want about 2.5kg. Your new filter will hold about 2kg if your baskets contain nothing but biomedia. If any of your baskets have sponge in there you will be holding less than 2kg.
Its probably going to provide at least as much biological filtration as your 2 internal filters, but not do as well mechanically because of the low flow rate. And if you are relying on filter output for aeration you may want to add in an airstone.
If you added a powerhead that directed flow and detritus in the general direction of the filter input it would help to reduce deadspots and the filter to gather up waste. A powerhead at the surface would aerate the water if the filter output isnt sufficient.
When you do a pwc do you turn the filter off like you would with an internal? I haven't used these before.
I do most of the time but have left it on once and it worked just fine. (fluval 407). With a 50% pwc my intake is still a good foot under water.
EDIT Now I put everything but my light on a gfci power strip so I flip one switch and only my light is left powered on
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