1. Fishfry Initiate Member

    Hi Everyone,
    Need your help! I have a 35 gallon tank with an Aquaclear 50 filter, I would like to use a cannister filter on this tank. What is the safest way to change filters without losing anmy fish. In this tank I have 2 gouramis, some neon tetras and a few rasboras.

    I tried adding the sponge and the bio portion of the filter when I did this change with my 35 gallon cichlid tank and lost most of my fish...any suggestions?
  2. pirahnah3 Fishlore VIP Member

    Just add the new filter to the tank, leave the old one in place for at least a month. That way the bacteria get a chance to grow into the new filter without causing harm to the cycle of the tank. I would also leave the old filter on the tank just in case of a failure. It would also give you a filter ready to go if you want to instant cycle a tank.

    What I also do for the instant cycles is I try to stick to one type of filter for HOBs that way I can just buy a new filter and put the new pad in the HOB on the running tank and take out the seeded pad for the new tank. Also keeps things easy for stocking parts for them as well.
  3. Fishfry Initiate Member

    Adding new cannister filter

    Hi pirahnah3,
    I don't have enough room on the back of the tank as where the HOB Aquaclear is. That's where I was hoping to put the hoses from the Eheim cannister?
  4. Lexi03 Well Known Member Member

    You should have no problems if you move the media from the hob and put it in the canister. But to be on the safe side, after the switch, test your water everyday for a week, and if the ammonia or nitrites rise, do daily water changes until you get 0 readings again.
    And I would not add any new fish to the tank until two weeks after you are sure the cycle is stable in the new filter.
  5. pirahnah3 Fishlore VIP Member

    I see, as stated I would put the pad from the HOB into the canister then. Depending on the canister i would likely recommend replacing the top filter sponges or pads with your HOB pad and put the bio media where it belongs. After a month or so you should get enough growth on the new media to remove your old pad and put the usual filter pads in. Testing during all of this is important to ensure that you don't unknowingly cause a mini cycle.
  6. Fishfry Initiate Member

    Thanks for all your advice. I bought an Eheim Professional 3 Ultra G65 Cannister Filter and hopefully will set it up tomorrow afternoon. Point taken on checking daily. I converted one of my other tanks to the same cannister filter but was not as careful about water testing and lost all of my fish.
  7. pirahnah3 Fishlore VIP Member

    some of the best advice is learned thru mistakes.
  8. Fishfry Initiate Member

    You are not going to believe this but after watching after 12 and 24 hours and not getting a terrible ammonia spike...reading after 24 hrs was 0.5. The water got a bit cloudy...anyone know why?

    Unfortunately I accidentally pulled the plug on my heater and the temperature dropped about 10 degrees and I lost a lot of my smaller fish. My gouramis and loaches are still okay.

    What a dumb mistake!!!
  9. Lupinus Member Member

    Probably a bacterial bloom. Is it kind of a white milky cloudy of different colored?
  10. Fishfry Initiate Member

    It is a white milky cloudy colour. What caused that? What can/should I do to fix...or do I just wait and it will go away on its own?
  11. Lupinus Member Member

    That's a bacterial bloom due to increased bacteria in the water column. It will settle itself out.