Built in filter - is it sufficient?

[Oonallee]

Hi guys
I've got a 260lt tank, a brand similar to aqua nova, with a built in filter in the hood. I use two types of sponge (fine and coarse) and the bio balls. These get rinsed once every couple of weeks on rotation. I don't use carbon as I've read it's no good with discus (?). Inhabitants are;

4 10cm approx discus
3 medium clown loach

So it's not overstocked. Water change once a week or so 30%. Everyone seems to be Ok but I have noticed one of the blue diamond discus is getting fin rot from time to time. I treat with melafix then it goes away, but will keep coming back now and then. My water parameters are all good, ph 6.8 and everything else normal, hardness, etc. The ammonia is fine as is the nitrite and nitrate.

I'm assuming the fin rot is coming back because the water isn't up to scratch. Should I invest in a canister filter like an eheim or is it really not going to make much difference?

I did actually purchase an eheim, but it got lost in the post from what I've now learnt is a disreputable well known online seller, goodbye $300 - but that's another story! I would be willing to part with the money again if it meant discus were happy little campers :)

[ILLUSN]

fin rot is telling me that your nitrates are creeping up between changes, try and keep them below 10ppm (i try and keep mine at 0 for the altums but its near impossible)

the inbuilt filters are ok but they do tend to be nitrate factories with so much aerobic activity if it were my tank id change more water and add on a canister full of biomedia to try and get some anerobic filtration going as well.

[Oonallee]

Thanks for that ILLUSN. Anyone know of a thread reviewing canister filters? & recommend a good supplier? Cheers

[ILLUSN]

cant beat an eheim for reliability age of aquariums has some good pricing