How long does it take to build up beneficial bacteria

Hello , I set up a 55g aquarium about 3 months ago with a penguin 150 filter (rated for 30g) . I only had a betta a few black neon tetras . So 3 weeks ago I bought a aquaclear 70 for the tank and was wondering how long should I wait until I can remove the penguin 150? or if I should remove it at all ? . I have aded some more fish (6 rummy nose ,6 neon tetras and a blue phantom pleco) and my amonia leves have been very low nitrates at around 20-40 with weekly 20% -30% water changes .

If ammonia and nitrites are zero ppm, then adequate bio-filtration. At some point you may remove Penquin or leave it with Aqua-Clear on this tank.
Regarding nitrate levels, I prefer to keep at 10 ppm or less. IMO nitrate at 20 ppm and higher will stress fish. Nitrate is controlled with water changes. If nitrate does not .drop to desired level, then increase frequency or percent total volume of water changed.

Six weeks minimum for new tank for biofilter to be effective. But adding Aqua-clear with fully functional Penqin would be fully functional in much less than 6 weeks.

Thank you , I will do a 40% water change next time and see if I can drop my nitrates below 10 and keep them that way. I have also read that extra filtration won't hurt it's just that I don't like my tank looking ao crowded with wires in the back. Thanks again for the reply.