co2 circulations?

Discussion in 'Carbon Dioxide (CO2)' started by mfcphil, 24 Nov 2009.

  1. mfcphil

    mfcphil Member

    Messages:
    426
    Forget the lack of plants as I am trying to get the flow correct before adding more plants

    Full Tank

    tank-full.jpg

    Tank Right

    Hydor Koralia used to send the Co2 on its way araound the tank....The Juwell filter is to be removed and I have bought a Eheim Compact 2000 to place in that corner

    tank-right.jpg


    Tank Left

    I Had flow problems around this area so I have added a Spray bar to my Fluval 305 to give a little better circulation around that side...the fow seems to be better going in a loop all the way around.

    tank-left.jpg


    I will always listen to your advice :)
     
  2. andyh

    andyh Member

    Messages:
    1,933
    Location:
    Derby
    Hello

    Looks good in principle and you are right to be concerned about flow in a planted tank.

    However, at this early stage its relatively easy to get the flow/co2 traveling round your tank, its once you fill it with plants, rocks and whatever else takes your fancy, that the challenge really begins as all these things will inevitably will reduce flow.

    I normally have my external filter return say in the back right blowing from right to left, then my powerhead on the front left blowing left to right. This creates a good circular flow as a start point, however may not be ideal once you have tall stems in.

    You will be constantly tweaking it, to eliminate dead spots :crazy:

    Hope this helps :?: ;)

    andyh
     
  3. ceg4048

    ceg4048 Expert/Global Moderator Staff Member

    Messages:
    8,953
    Location:
    Chicago, USA
    I think it's a really bad idea to mount a spraybar vertically. Looks like you got BGA up front except along the axis of the spraybar. Flow from the bar on left conflicts with flow from the right where the Koralia is. Try mounting the spraybar horizontally along the back and play with the Koralia's position so that it's flow is either additive or at least complimentary. Are you dosing enough NO3? What total flow rating to have relative to tank size? How much light do you have?

    Cheers,
     
  4. mfcphil

    mfcphil Member

    Messages:
    426
    What do you mean by
    Tank Juwel Vision 180 litres bowed front

    Potassium Nitrate & Potassium Phosphate (SAME BOTTLE)
    Potassium Nitrate 39g to 500ml for the solution
    Potassium Phosphate 30g to 500ml for the solution

    dosage = 25ml 3 times per week

    Trace
    18g to 500ml for the solution

    dosage = 25ml 3 times per week


    Mon – Trace
    Tue - Fert
    Wed - Trace
    Thur -Fert
    Fri – Trace
    Sat - nothing
    Sun - 50 % water change THEN Ferts


    Light 2 times Juwel T5 about 8 hours a day...Co2 on 1 hour before lights come on and goes off 1 hour before they go off.


    As I said I am listening to all your advice so I will move the spray bar. Thounght it was moving the Co2 away from the plants and there was a dead spot in the bottom left front corner
     
  5. ceg4048

    ceg4048 Expert/Global Moderator Staff Member

    Messages:
    8,953
    Location:
    Chicago, USA
    Well, additive means the the two sources of flow are pushing in the same general direction so that their energies combine to move water in that direction. If one is pushing water to the right while the other is pushing water to the left, you just have a collision and the two flows tend cancel each other's energy out, so they subtract from each other. You want to create a flow like that in a river, where the majority of the flow is along the same direction.

    In the case where you mounted the spraybar vertically, can you imagine what happens when the water impinges on the front glass? Some flow squirts out to the left and stalls against the left wall, some squirts out to the right, but it collides with the flow from the Koralia and stalls. Some flow squirts above or below and collides with the flow coming from the holes above and below. So in general the movement of water coming from the vertically oriented bar is incoherent, because water squirts out in every direction and weakens the total energy, especially if it conflicts with the movement coming from the Koralia.

    A better idea is to aim for uniform flow, where all the energies are headed along the same path. If you mount the bar horizontally and point the holes level or very slightly down, you are creating flow distributed along a greater section of the tank. The water impinges on the front glass and most of the energy heads downward to the bottom. A little escapes off to the left and right but generally in the same direction from each hole. The downward flow the hits the gravel and has a greater tendency to be deflected to the back. Again, you do lose some to the left and right, but that's OK. If the flow is strong enough it then hits the back wall and rises up along the back wall.

    It's by no means perfect and you need a strong flow rating from the filter but you can, for example mount the Koralia on the back wall pointing diagonally or pointing forward in the same direction. If your filter is strong enough you can add a second bar to give greater coverage along the tanks length and this will lower the velocity of the jets as they exit each hole.

    You really have to play around with positioning of each pump/filter outlet, and don't forget that you should experiment with different placement of the diffuser, depending on aesthetics as well as effectiveness. If this is a 180L tank then the 10X rule says you need 1800LPH of flow "rating" ideally.

    I've never had a bow front so I can't say how this affects the flow distribution. The bottom line with flow is that a majority of the plants should gently sway in the current. As biomass increases the flow becomes more critical.

    Shouldn't the dosing be 40 ml 3X per week? You may want to double check that.

    Cheers,
     
  6. mfcphil

    mfcphil Member

    Messages:
    426
    Thanks very much for the great input I will change it around before I get any more plants.

    The Ferts are at 25ml 3X per weeks...this was taken on advice also, do you thing I should up them to 40 ml 3X per week?

    I would like to keep the ferts at 25ml simply because its easier...so what do you think would be the recomended amount of powders to the 500ml bottle?
     
  7. mfcphil

    mfcphil Member

    Messages:
    426
    Juwel corner filer removed joint spray bar added horizontally.
    Eheim Compact Pump arrives this week and will be added for more flo, although not sure where to put it


    tank-2.jpg
     
  8. ceg4048

    ceg4048 Expert/Global Moderator Staff Member

    Messages:
    8,953
    Location:
    Chicago, USA
    Well really, you know, you ought to get more plants in there as quickly as possible instead of waiting for everything to be just right. Waiting for things to be just right is really is having the cart before the horse. More plants help to stabilize the tank faster. If the dosing strategy is easier for you then stay with it but watch out for deficiencies. Since you're still playing with the flow we might assume for now that the BGA is flow related but if it continues after that then you have to look at increasing the NO3 levels. I see dark spots on two leaves of the foreground crypt. Is that algae or just debris?

    I think the mixture is OK since we can call this a 40G so that's double the reference tank dosing numbers. It's just that normally, for EI, that 500ml should be for 12 servings, so 500ml/12 is around 40ml per dose.

    Cheers,
     
  9. mfcphil

    mfcphil Member

    Messages:
    426
    Ok will up the dosage to 40ml 3x a week ;)

    My Eheim Compact 2000 Pump has just arrived any nice tips as where to put it?

    Oh and just waiting for plants to come
     
  10. Mortis

    Mortis Member

    Messages:
    355
    Point the Koralia down a bit so that when it pushes the CO2 bubbles left, it also pushes them down so that they take longer to reach the surface, giving them more time to dissolve
     
  11. mfcphil

    mfcphil Member

    Messages:
    426
    moved it to the corner is that better

    tank-3.jpg
     
  12. ceg4048

    ceg4048 Expert/Global Moderator Staff Member

    Messages:
    8,953
    Location:
    Chicago, USA
    Yeah, that looks like a good baseline configuration. Play with the angles; straight ahead, slightly down, slightly inboard and so forth. Make sure all the plants sway a bit. Leave it for a bit and make another change. We can only tell you theoretically what ought to be. The solution in that particular tank might be different in the end. I'll crumble up small amounts of flake food, throw them in, and see how they particles move and where they end up. That helps you to visualize the flow if you get cross-eyed watching the bubbles. :angelic:

    Cheers,
     
  13. mfcphil

    mfcphil Member

    Messages:
    426
    One alteration needed!

    The Fluval 305 really was not working with enough pressure to use the full length spray bar so I replaced the normal Fluval end and added the Eheim Compact 2000 Pump and attached the spray bar to that

    I will work on the flo direction as you advised.

    Many Thanks again :thumbup:

    tank-4.jpg
     
  14. mfcphil

    mfcphil Member

    Messages:
    426
    Think the new flow is a big improvement...Still getting the smelly Blue-green Smear algae in the substrate :(
    I am picking it out before water changes....on-going battle!
     

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