Changing Filter - What Process?

Hi,

I have a Hagen Marina i110 filter in my 54L tank which has been there since the tank set-up in mid-October. It doesn't seem to circulate the water surface much, if at all, although it definitely has a strong 'waterfall' like effect immediately in front of the filter. I haven't changed the cartridge yet as I don't want to risk losing the good bacteria when the tank is still relatively immature. Therefore, I'm thinking of reincarnating my goldfish's (RIP) first filter - a Clearjet 1 (which, from recollection, only housed sponge) - and having this as a second filter.

Also, thinking ahead, I notice that the cartridges contain carbon and zeolite http://www.rakuten.co.uk/shop/aquapet/product/A134/ , and from recollection from my goldfish-keeping days, ought to be removed if adding medication. Then, if the tank should need to be medicated at any point, the Hagen Marina i110 could be removed, or the Clearjet 1 transferred into another tank and it set up as a quarantine tank (I have an old, slightly smaller tank which could be set up for this purpose if/when the need arises).

My thoughts are:

(1) to add the Clearjet 1 with some sponge firstly into the 54L tank, in addition to the Hagen Marina i110 filter, and that hopefully after some time (how long?), this Clearjet 1 filter would then be considered 'cycled'. Is this counted as a "fish-in cycle" or not, given that there's an existing filter already in there  ie do I need to take extra precautions to ensure that all is well (or am I putting the fish at risk in any way), and would I need to do more frequent water changes than my current 20% weekend changes involving siphoning and 10% mid-week non-siphoning changes? (Sometimes I just do a 20% change with siphoning every 5 days rather than a weekend water change and a mid-week mini water change.)

(2) once the Clearjet 1 is fully cycled, to replace the Hagen Marina i110 cartridge, which might improve its water circulation on the surface of the tank.  Would the replacement of that cartridge then count as a new "fish-in cycle", requiring extra precautions, etc.

It's possible that, once all the above is done, given the extra filtration, I may consider adding a third and final shoal of fish which would bring me up to full stocking capacity.

Does this sound sensible enough?  Also, would I be correct in thinking that if the Clearjet 1 were fully cycled, then a QT could be set up on an as-needed basis  ie immediately as the need arose by simply transferring across the filter and some of the water from the main tank?

Sorry for the long posting. Everything has been going well so far with my 6 x-ray tetras and 6 pygmy cories, and I want to keep it that way! Many thanks.

Thanks for posting this fcmf, I was just about to post a similar question when I saw yours.

I would like opinions please.  As you may know we have our little 22 litre Aquanano 22/30 which has now had it's first babies added.
We have started off with 6 Endlers from our local MA. They gifted us an extra one because I couldn't make up my mind whether to get fully stocked all in one go  and the fish were 5 for £11 and I wanted 11 or 12 of them.
Unfortunately, despite the fact that MS taped the bottom of the bag the last one kept getting stuck in a fold near the tape and I had trouble getting him out and in the end had to cut the bag a little way from him and let him out that way.  He never looked happy and within a couple of hours he started "spiralling" and sinking before trying to swim and eventually he sunk to the bottom but I cannot find him and haven't seen him since so assume he didn't make it.

Four more disappeared completely and we were left with just one very active one.
I was so upset, couldn't see the little darlings anywhere.
I didn't even want to look in the tank this morning and having criticised number 2 grandson's overstocked tank didn't know how I was going to admit that within a few hours of putting them in the tank I had killed them !!

Looking at the lone survivor after breakfast I noticed there were TWO, then three then four and five . Pheww!! Great relief and excitement.  Goodness knows where they have been. (Although I do have a "dip" at the back with a little clay pot arch.)

I am now paranoid that I am going to lose them!!  They seem active, have fed a bit and have been exploring the tank.
So the only missing one now is the one that got stuck and probably damaged by me trying to release him.

Since I started cycling the tank I have had a homemade sponge filter in there together with the overpowered supplied filter. This was with the intent of having a ready made filter to go in the hospital tank should it be needed.

These fish are tiny tiny things and I was worried that the spray bar I made to reduce the flow  would still make it too powerful for them but I've just noticed they seem to be "playing" in it.

They didn't seem to like the bigger bubbles from the sponge filter and avoided that part of the tank.  I have now turned that one off and almost straight away they were swimming around it and seemed to be eating algae from the top of it.

My question is this:
If I leave this sponge filter turned off but still in the same tank, will I still have the bacteria which I hope has been growing in there over the past 5-6 weeks. Would it help if I turned it back on for an hour of so a day to refresh the water in it. Best of both worlds.

Sorry, that was a long winded way to ask a basic question but I wanted to set the scene!!

Any advice greatly appreciated.  Everything I've read (and was told by MA) suggests that these Endlers are hardy but having managed to kill one before he'd even had a look around it'd made me very nervous in case I lose them all.

Thanks for the reply Sue.  Yes it's just a simple air pump, no bleed or anything. Perhaps I could make a pin hole in the tubing, That might work eh?

One of the Endlers is a bully and keeps charging the others and going nose to nose with them. Hope he doesn't frighten them to death. I'm pretty good at that myself!!

It is designed that way to try to force you to buy new ones on a regular basis, to make more money from you.

He is a definite bully. He chases them and their top fins go down as they swim away but his is upright. Will probably get the rest on Tuesday so he'll have more competition