New Filter Question

Discussion in 'Filters and Filtration' started by Francine, Jun 20, 2018.

  1. FrancineWell Known MemberMember

    I apologize if this has been asked and posted but I couldn’t find any direct answer...
    Today I replaced my old filter (was getting old and I didn’t like the set up of it)
    I got the Fluval C4 HOB... my question is... I kept my old filter bags (carbon was already emptied out of them from having to medicate a while ago) and I’m not sure where the best place to put them in the new Fluval would be to try and keep most of my bacteria alive and working... in the back of the Fluval it has a basket that contains carbon (in a sack) I was able to fit (because it’s very large to allow you to customize it how you want)
    Bottom- one old filter bag
    Middle- carbon bag
    Top- second old filter bag...
    Is this the best place to put it?
    The total filtration system works like this
    1st and second stage- is a 2 stage mechanical filtration using poly foam (one side is denser than the other so it technically uses 2 stages... goes through the dense part and then the less dense part

    3rd stage- (this is where I put my 2 established filter bags) this is the carbon filtration part- again I layered them (old filter bag, new carbon bag, old filter bag)

    4th stage- bio pad.. it’s a tiny little pad that the water trickes through to the final stage (this is where they state that the bacteria colonize the quickest... that’s why I put my old established bags before this stage)

    5th stage- c nodes
    I am just worried if the carbon is going to do anything to my old established bags or not...
    I really don’t want to have to completely recycle because it was already finished...
    Any tips or help with anyone familiar with this filter would be greatly appreciated!

  2. AquaticJFishlore VIPMember

    The only thing you need to be replacing is the carbon. The sponges/bio media should never be replaced unless they’re literally falling apart. Instead, rinse them in a bucket of tank water or dechlorinated water. Never unconditioned tap water. It’s also best to just change one piece of media per month. As long as you were able to fit most of your old media somewhere in the new filter, you should be fine. Also, As long as your filter bags were put right back in immediately after removing the carbon. Though I can’t make any promises. Hope I answered your questions.

    Edit: it might help of you could show me what the old media looks like. The trickle system is meant to house both nitrifying and denitrifying bacteria. Denitrifying bacteria actually turns nitrates into atmospheric nitrogen, but can’t live in many filter because of their need for oxygen. That’s why trickle or wet/dry filters usually have lower nitrates.

    Last edited: Jun 20, 2018
  3. FrancineWell Known MemberMember

    What I meant was I got a whole brand new filter... completely different from my old one... so ALL the media is different....
    I know to never replace them but that is not what I was asking as it was not an option...
    I used to have the tetra whisper ex 70 and I hated the stupid media bags... everything is all in one so if you ever have to medicate you have to cut open the filter bags and take out the carbon which is nasty (especially because like I said I am aware not to change that stuff until it’s falling apart) now I have the Fluval c4 hob.... much easier because I don’t even have to have carbon if I don’t want it I can put whatever I want in the basket... Nitra sorb, purigen, etc... plus my other pump was getting old... so my question was:
    I kept my old media from the tetra and was asking if the best spot in the Fluval to put it was (I have 2 old cartridges) one on the bottom of the basket, then the carbon, then another old media bag... my only concern with it being in that spot is will the carbon do anything to my good bacteria or will it just continue to get washed along to the next stages (everything after the carbon will hold good bacteria- the little pad and then it trickles to the c nodes..

    Also the carbon was removed from my old media bags looong ago so I know they are good and it was literally 30 seconds... took out my old media rinsed it in a bucket of tank water.. crammed them in the basket between the NEW carbon bag and hung the filter and primed it and plugged it in.... so the old media wasn’t out of water for at most 1 minute lol


    Last edited by a moderator: Jun 21, 2018
  4. leftswerveWell Known MemberMember

    Never changing the filter bags is not a good idea. The reason: when they do fall apart, you have to put pieces of them somewhere in your new media. As long as you are using pieces of the old bio home and media in the new filter, you're fine.
    In the future, replace the replaceable filter regularly and the BB will grow where is supposed to and designed to in the new filter.

    Caveat: assuming your filter is designed with a separate BB home (op, yours is).
  5. FrancineWell Known MemberMember

    I’ve never replaced my filter material until it was ready to fall apart and then I only change one part at a time... like a month or so in between.. and have always had a cycled tank... everyone does things differently but usually companies that tell you to replace things every month are just looking for more money... but everyone has their own way that works for them...
  6. AquaticJFishlore VIPMember

    Nah the carbon won’t have an impact, as long as you get it in the filter wherever you can. I’d assume your bacteria will be fine switching filters. In theory, when cycling a brand new tank, it’s best to put bio media before carbon. Even then it’s not going to cause you to not cycle. Anyway, you already have bacteria so it’s totally fine if it’s near, before, behind, the carbon.
  7. FrancineWell Known MemberMember

    Thanks someone finally read my actual question and answered it lol much appreciated!
    Do you know how long I should leave it before it will start to colonize on the bio pad and c nodes? Like just roughly... I want to get some of my other stuff back in there but there’s no room with the established filters... I know there’s not an “exact” time but what would you give as a rough estimate... everything is still testing ok... but I know the bacteria can like double in 24 to 48 hours so I was thinking like maybe a week or 2 just to be sure?
  8. smee82Fishlore VIPMember

    Honestly if your replacing the whole filter i would just run the new filter with the old filter for 2 weeks to a month.

    As for the order mechenical 1st then bio and chemical last.
  9. FrancineWell Known MemberMember

    I would have but my lids only have the spot for one hob filter... the other lid doesn’t have the cut out and I don’t want to be left with a big hole afterwards... and I can’t take it off completely because I have kids and dogs and it would end up with more crap in there then should be lol... plus my lighting is attached to the lids and I have a planted tank so I need the lights... seems to be working fine the way I have it so far so let’s just hope... all my tests are fine and my nitrites are back down to 0
  10. smee82Fishlore VIPMember

    If you cant run them together your mechenical filtration doesnt matter as much. If it doesnt fit the new filter and you have separate bio media you can toss it. Add all your old bio media to the new filter and if you still have more room add more new bio media. Also make sure any carbon, purigen or chem media is last.
  11. FrancineWell Known MemberMember

    Yes thank you... someone actually read my question and answered it... everyone else isn’t even reading my question... all I wanted to know was if it was ok to put all my old bio material in the carbon basket with the new carbon because it’s the only place it would fit... and they say it’s ok... because the rest of my bio material (new stuff) is right after that... so my bacteria will just wash down into my pad and c nodes and settle in there within time... now all I need to know is how long it will take for the new bio material to get enough bacteria in it... like how long should I leave my old bio material in there?
  12. bizaliz3Fishlore LegendMember

    You've said that a couple times now....I think everyone read your question and was just offering other suggestions to consider. I don't see anything wrong with that. Me personally, I like having more than one filter. So I would run them both permanently. So this wouldn't even be an issue. But you said you can't do that due to your lid. Which is understandable.

    I would wait like a month before removing the established media.
  13. FrancineWell Known MemberMember

    It wasn’t so much your reply as some of the others lol such as telling me how often to change my media and things like that... I know all that stuff... I just wasn’t sure how the carbon would effect the old “good” bacteria is all... and yes I know you were just trying to give me some added advice and I would have done that to begin with if I had the choice but unfortunately I don’t... I wish I did... I can’t even find the proper lid of course the only one I can find is the side that doesn’t have the cut out... go figures... and thank you for your advice on running it like this for a month...
  14. bizaliz3Fishlore LegendMember

    I like using glass lids. They leave an opening in the back so you can put whatever you want. And then they come with a plastic piece that can cut and attach tightly to the glass lid in the areas between the filters or whatever you want to have have back there. That way there are no openings.
    But those glass lids require a separate light...I don't know what you can afford.

    But that isn't the subject here.
    When I add media to a new filter to cycle a QT tank or a hospital tank, I always situate it so that it is the first thing the water hits...I don't know if that is the "right" way or not. But that's how I do it. And I have done it many times.
  15. FrancineWell Known MemberMember

    Thanks I have mine right after the 2 mechanical filtration parts... so it would be basically the same I think because all the mechanical filtration part are is a dense foam and a less dense foam that traps bigger and smaller particles... then I have it in the first stage of the biological filtration where there are 3 stages (carbon, bio screen thing, and c nodes)
    I plan to eventually take the carbon away anyway because I never usually use it and replace it with some denitrate or purigen or something else.. I’m also going to add some other bio filtration I’m with the c nodes as that basket is fair sized too... I just don’t want to go messing around with too much until I get everything stable again.. and make sure it stays that way...
    The way my lids are is half glass half plastic and they are for some reason an odd measurement... I’ve though about going to one big lid instead of 2 or trying to switch them as I HATE them... but one thing at a time... lol if you have any brands of tops that you like feel free to send them my way
  16. smee82Fishlore VIPMember

    Carbon isnt bio media its chemical media and should be last in your filter after your bio screen thing and c nodes(i dont know wjat eithe rone of them is).
  17. FrancineWell Known MemberMember

    And I wasn’t meaning that carbon was bio media... I know it’s not
    Hmm. Not in the Fluval... they don’t have it designed that way...
    It goes:
    foam pad thing- it counts as 2 stages- because it has a dense side and then a less dense side
    Then the carbon
    Then the bio screen
    Then the c nodes
    Then back into the tank..
    That’s how they have their system set up
    My sons canister filter for his 70 gallon is the same way (he has the Fluval 406)
    If you look at the attached picture it shows how the stages of the one I have (C4) works

    Attached Files:

  18. leftswerveWell Known MemberMember

  19. FrancineWell Known MemberMember

    Yes... I already said that my question was answered...
    And then someone started talking about different types of lids and I hate mine so then I asked if they had any brands that they know are good I would appreciate the recommendations... that’s all... no need to be crabby... my goodness... when I was talking about people not reading my question is was more directed to the people that were telling me to change my media every month and so on and so forth... that’s what I meant about people not answering my question... I know how and when to change media I have just never changed pumps on an already cycled tank... and all I was wondering about was if the carbon would effect my good bacteria materials... that’s all I wanted to know.. and as for putting the carbon last... I don’t (as a lot of people) even use it unless they want to remove medications or something... but I put it in just because it came with it and it’s not going to hurt anything by having it in there for a couple weeks until it exhausts....

    Oh nvm you got rid of your post I guess....
    Last edited by a moderator: Jul 9, 2018

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