Need Help Chosing Lighting Fixture for Low Light Setup

Discussion in 'Lighting' started by FishyDMD, Nov 27, 2012.

  1. FishyDMDValued MemberMember

    Hi everyone,

    In another post ( I learned that the plants in my 29g were not thriving due to a lack of sufficient light and possibly a lack of nutrients. As a beginner my goal with this tank is to keep only low light plants and not have to worry about adding CO2 or dosing liquid fertilizers. Right now all I have is anubias and I plan on adding java moss and java fern in the future. I have started dosing with LeafZone weekly with water changes as recommended by a member; however, I'm still having trouble coming up with a solution for proper lighting.

    Right now I am running a single 18 watt daylight T8 bulb. I purchased a dual T5HO setup this weekend at the recommendation of my LFS but quickly found out that it was way too much light for a low tech setup. Luckily, the LFS will allow me to return T5 fixture, but I'm unsure what I will need to keep me in the low light range. There doesn't seem to be a lot of options for my tank between the single T8 and the dual T5HO. Here is what I have found online. Would either one be a good choice? Or should I just stick with the single T8 and hope for the best?

    Single T5HO from Catalina:  

    Aqueon Dual T5 (I'm assuming these are normal output):  

  2. Matt BWell Known MemberMember

  3. AlyeskaGirlFishlore VIPMember

    Not all T5HO fixtures have good quality ballasts. The Coralife T5HO duel fixture would put you in the low/moderate range for the height of your tank. It's not one of the good High output fixtures.

    The Catalina is another good quality high output fixture.

    If you picked up an Aquaticlife duel T5HO fixture that would give you too much light as its a good quality fixture. Each bulb has its own reflector which makes a difference.


  4. FishyDMDValued MemberMember

    Thanks for the input. The height of my tank is 18 inches and I would be using a glass canopy. After studying Hoppy's chart, it seems that the dual Aqueon fixture would most likely place me in the low light category. This fixture is normal output, correct?

    A few more questions:
    Does the Aqueon fixture have reflectors? How high does it sit above the tank?
    How often should T5 bulbs be replaced?
    Are the normal output T5 bulbs similar in output compared to T8?


  5. Matt BWell Known MemberMember

    I have never owned the aqueon fixture but most fixtures will have a reflector of some sort, they vary in effectiveness from what I understand. From the pictures, it looks like it will sit right on top of the glass. A 28w t5 produces about the same light output as a 32w t8 so t5's are more effecient.
  6. FishyDMDValued MemberMember

    Thanks Matt. I have heard that lighting fixtures should never be placed directly on the glass to prevent overheating issues. Is this true?
  7. Matt BWell Known MemberMember

    I've heard that as well, I probably wouldn't do it with a T5HO but I had a 48" dual T5NO sitting directly on the glass for a long time with no problems. I would think the manufacturers take this into account as the only ones I've seen that are made to sit right on the glass are the normal output while every high output I've seen is made to leave a gap if the legs are used.
  8. FishyDMDValued MemberMember

    Thanks again Matt, I really appreciate your help. One last question: the Aqueon fixture comes with a colormax lamp and a 6700K lamp. Should I replace the colormax bulb and run two 6700k lamps?
  9. Matt BWell Known MemberMember

    No problem! I can't find any useful information on the colormax bulb as far as temp or how useful it is to plants. I think I'd try it and see how it goes, you can always get another 6700k down the road if you're not getting the results you want.
  10. FishyDMDValued MemberMember

    I ordered the Aqueon T5 fixture today, thanks again for the advice.
  11. ZiabisWell Known MemberMember

    My tank is 20" high. How do I know if I need lots of light or not. I also use a 1 T8 full spectrum daylight bulb.

    I am using basic plants see signature. Do I need low, medium or hight light. NO CLUE....
  12. Matt BWell Known MemberMember

    No problem, glad to help. :)

    You have alot of low light plants in there but the sword I believe is medium to high, I'm a bit of a newbie to plants myself so I think your best route would be to start a thread of your own, you'll get alot more input that way. :)
  13. FishyDMDValued MemberMember

    Well, I finally got the Aqueon T5NO dual light fixture set up today and it's perfect. Just the amount of light I was looking for! Here are some before and after shots of the tank:

    Single 18watt T8

    18wattx2 T5NO
  14. SiggiWell Known MemberMember

    In the two images, diaphragm (aka /f-stop value) and exposure-times are the same, right?

    That will be quite a shock for the plants...
    Consider using only one of the bulbs for the first few days. Then, before you begin using the 2nd bulb, put in some surface plants, like water lettuce...
  15. AlyeskaGirlFishlore VIPMember

    That looks great! Your plants will appreciate it.

  16. Matt BWell Known MemberMember

    Looks much improved. :;th

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