Lighting help

Discussion in 'Lighting' started by angusship, 27 Aug 2008.

  1. angusship

    angusship Newly Registered

    Messages:
    5
    Hi guys

    I have a 1500mm (L) x 700mm(W) x 500mm(H) tank

    I have 4x 54w T5 6500k tubes so far
    I was wondering if I should add some 10000k bulbs or some compact tubes.

    I want a HC carpet with stem plants at the back ,a couple of them will be red.
    I have bottled co2 and loads of filtration

    any suggestions would be gratefully accepted.
     
  2. ceg4048

    ceg4048 Expert/Global Moderator Staff Member

    Messages:
    8,952
    Location:
    Chicago, USA
    Hi,
    You can add as much light as you want to get whatever color rendition you desire, however you will need to ensure proper flow and CO2 injection rates. I would suggest you stick with the lighting you have now and get a handle on CO2 before proceeding to add more light.

    Cheers,
     
  3. angusship

    angusship Newly Registered

    Messages:
    5
    Thanks for your comments
    I have a Ph controller and a redsea vortex 500
    I was debating on getting a second bottle and another vortex 500 to ensure enough CO2.
    I will wire 2 solenoids to the controller.

    They should perform better than an inline CO2 setup.
     
  4. ceg4048

    ceg4048 Expert/Global Moderator Staff Member

    Messages:
    8,952
    Location:
    Chicago, USA
    Hi,
    Yes, evidently the Red Sea unit get good reviews though I haven't seen it for sale here in the UK. The fact is though that no matter how good your diffuser unit is, the CO2 laden water still has to be distributed quickly and evenly into the tank. The larger the tank the more difficult it is to achieve even and high saturation of the water column simply due to the volume, so what is as important as your diffuser is water throughput and circulation patterns in the tank. This means that your filter and/or auxiliary pumping will need to meet or exceed the 10X tank volume per hour rule of thumb. Big tanks suffer more than most from poor circulation due to frictional forces and momentum loss. The deeper the tank the more chronic this problem becomes. If your priority will be carpet plants then the throughput and circulation issue has even more relevance. Carpet plants are the least forgiving of poor CO2 and they wither away without the slightest hesitation. Carpet plants operate at a disadvantage because they are low and are generally the furthest away from the source of CO2 injection. Their proximity to the substrate means that the hydraulic flow rates are at their lowest and that detritus and decaying particles tend to settle in this region and so they have the toughest time obtaining nutrients/CO2 while being typically nearest to the bulk of organic waste produced in the tank.

    For a tank of this size I would very much agree regarding the addition of a second diffuser, the effluent of each to be located at opposite ends of the tank. In this way the distance that CO2 laden water has to travel is less and the concentration more evenly distributed.

    Inline systems can and do work well, so don't ignore their potential. I use inline diffusers in a large tank and I have no difficulty growing carpet plants - however they are part of a system that focuses on high, stable injection rates, high water throughput and careful attention to circulation patterns which takes full advantage of the flow rates. These factors have an identical impact regardless of any diffusion technique.
    [​IMG]


    A pH controller can work and many use it successfully, but the controller cares more about maintaining a stable pH as opposed to a stable CO2 concentration, so we tend to regard the controller more as a fail safe and monitoring device while using a timer controlled shutoff solenoid to regulate injection and a dropchecker filled with 4 dkh water as the main concentration measurement device.

    Cheers,
     
  5. angusship

    angusship Newly Registered

    Messages:
    5
    Thanks for the great input

    I'm still needing help with the fact that the width of the tank is 700mm wide.
    thats a bulb every 17 cm not very much light.

    also 10000k bulbs are used in a lot of tanks in the USA will these help red plants?
     
  6. ceg4048

    ceg4048 Expert/Global Moderator Staff Member

    Messages:
    8,952
    Location:
    Chicago, USA
    Hi,
    10,000K bulbs have as much impact on red plants as 6500K, or any K rating for that matter. I have not seen any relationship between K value and growth of any plant, however, as the K value rises so does the blue content thereby washing out the red in the plant. If you want greater impact of the red then simply use some bulbs that have red in the spectral characteristics. Any pinkish bulb (like Grolux or their clones) or even any low kelvin value bulb will do the trick but don't overdo it otherwise the tank tends to look eerie. You can also strategically locate the bulb directly over where you plant the red plant to maximize is effect.

    Remember that Kelvin values are for our eyes only and have no bearing on plant growth or performance. As discussed earlier you can add more bulbs if you are finding that the pattern you have is a bit on the dim side, but just remember that you will pay the penalty later on by having more stringent CO2 requirements... :rolleyes:

    Cheers,
     

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