Will This Lighting Be Enough For Coral In 2g Reef Jar?

Discussion in 'Saltwater Aquarium Lighting' started by ParrotCichlid, Apr 17, 2018.

  1. ParrotCichlidWell Known MemberMember

    Gathering the materials together for my next build a reef jar with a volume of about 2g.

    I was pretty stuck on lighting with it all being so small and made out of plastic.

    Picked up a desktop lamp and 12w LED bulb which is 6500k spectrum and 1500 lumens. Its the equivalent to a 100w normal bulb apparently. I'm just a little concerned about the 6500k spectrum?

    Will this lighting grow coral?
  2. stella1979ModeratorModerator Member

    Hrmmm, wish I could answer your question, but I couldn't be sure. The light would probably support coral, but I'm unsure if it would grow well or produce the best coloration. I think we need to ask @Lorekeeper about this. :)
  3. JesterraceWell Known MemberMember

    Tough call as it wouldn't take much for the light to penetrate. I wish Kessil's A80 Tuna Blue was cheaper as it is a great nano light. Personally I wouldn't use a desk lamp for coral growth but then again it is only a 2 gallon jar. You could try this:

    The advantage there is you would be getting closer to a full spectrum light and corals tend to do better under full spectrum IMHO.
  4. LorekeeperWell Known MemberMember

    A lumen rating would be nice (might be on the bulb's base somewhere).

    On my jar, I used a 4 watt 300 lumen LED bulb and was able to grow some zoas and gsp a bit. But, colors were pretty bland and growth was minimal. If it were me, I'd order a cheap PAR 30 from eBay. I'm using one on my 5.5, and ordered another to go with it. They're about $4 a pop for the 15W version, and will offer a nicer spectrum
  5. ParrotCichlidWell Known MemberMember

    Very interesting. The bulb i have is 12 watt and 1500 lumen rating. But the spectrum is 6500k? What was the spectrum on the 4w LED you used? If you don't mind me asking.

    Thanks for replying though :) I'm just really clueless with coral. Had plenty of saltwater tanks but not so much coral.

    Nice find thanks. But if the led bulb isn't good enough then i will probably build a small panel as its very cheap to put one together or even one of the PAR 30 as @Lorekeeper said. Was just hoping the bulb option would work.
  6. LorekeeperWell Known MemberMember

    My bad, I thought I mentioned it in my first post! I was half asleep, lol.

    It's a 5000K bulb. Corals do fine under warmer lights (5000k+), you just won't get the same color out of them. In short, you can totally use that bulb, you're just going to have to understand that most corals will end up fading to an ugly mix of brown under it. They'll be healthy, just not pretty.

    Since that bulb is so bright, I'd be careful. 1500 Lumens on a 2 gallon jar will be far, far too much with the lamp just above the surface of the water. My bulb was pretty weak, but even a 600 lumen bulb that I tried caused my zoas to recoil for a few days. If you do use that bulb, try to start off with it as far above the jar as possible, and then you can consider moving it downwards.

    Here's the bulb I used over my jar for a few weeks before moving it to my 5.5 - E27 15/21/27/36/45/54W PAR30/PAR38 LED Coral Reef Plant Grow Light Tank Aquarium | eBay

    Good color, cheap, and has lasted me 2-3 months so far. Doesn't get hot. That'd be enough to keep softies, LPS, and some SPS in the top quarter of your tank, imo. Only downside is that it takes about a month to get into the states, since it ships from Hong Kong.
  7. ParrotCichlidWell Known MemberMember

    Thanks Lorekeeper :)

    I've decided that I'm not going to use the 12w LED bulb, getting decent colouration out of the coral is far more important.

    It looks a great bulb that you got I'm just hesitant on 1 month shipping.

    Do you think something like this could work?


    Although it would only cover about half of the jar. So it would only make use of half of the LED lights on the unit.

    Or even something like this?

  8. LorekeeperWell Known MemberMember

    Both of those would work, IMO. If you're willing to spend around 10-15 pounds, why not go ahead and go for an ABI par38? Pretty much name brand of the Chinese bulbs. I've heard good things about them, and they just screw into a lamp.
  9. ParrotCichlidWell Known MemberMember

    I've had a look on ebay and amazon and can't seem to find any ABI Par38 bulbs of correct spectrum in the UK.

    Do you think the 3w of led would really be enough for a 2g jar? Just seems very low powered.
  10. LorekeeperWell Known MemberMember

    If its 1500 Lumens, then yes, it'll be plenty.
  11. LorekeeperWell Known MemberMember

    To give you an idea of my 300 Lumen bulb, here it is about 8" above a 3 gallon rubbermaid "lagoon". Not really any corals in here (well, there's some GSP and a zoa, but neither are happy due to a peroxide dip a few days ago), but both the caulerpa and the chaeto are doing fine under it. Granted, there's only 5" of water in the tank, but it penetrated fine in my jar as well.

    FTS 4-20-18.jpg
  12. ParrotCichlidWell Known MemberMember

    Very interesting thanks Lorekeeper. I like that rubbermaid lagoon the bulb definitely is bright.

    The particular LED units i linked to above are not 1500 lumen. They don't list the lumen outputs on the listing. What is concerning me is that the LED light i was considering is 3w and made up of 48 LED bulbs. The lower the wattage of each LED the less the penetration if i remember correctly?

    The lower the watt the lower the effectiveness of them? This is what i have found with LED grow lights anyway.

    For example the PAR38 bulbs are so effective because they are made up of 3w LEDs. The bulbs in the unit I'm considering wouldn't even be 0.1w each.

    Do you think something like this would be better?

    Each LED is 3 watt contains 10 of the LEDs total lumen output is 1500. I would only be able to get the jar under about 4 of the 10 LEDs on the unit though.
  13. LorekeeperWell Known MemberMember

    I think that any of the above lights would work. You kinda have to take a chance when ordering from a chinese manufacturer (there aren't always reliable reviews), but most of the time they'll do their job.

    I'd honestly be looking for a par 30 or par 38. That's going to alleviate any overhang issues, and allow you to get as much light as possible INTO the jar. The last fixture you listed would be fine, you're just looking at a massive amount of overhang.
  14. ParrotCichlidWell Known MemberMember

    Well i kind of got a crazy idea. Why not do two or three jars? I was thinking that i could possibly do two marine and one freshwater planted jar under that 18" light posted above.

    Something like this

    Jar 1 (Reef)
    Jar 2 (FW Planted)
    Jar 3 (FOWLR Small Fish)

    Do feel free to tell me if I've completely gone nuts.
  15. LorekeeperWell Known MemberMember

    You're nuts, but I love it!

    Nah, I actually did something similar a month or two ago. Had a 12" LED strip, and had macroalgae in one jar, some brackish shrimp in another, and some basic plants in the third.

    Only thing that I'd be concerned about is the FOWLR - If the jar is still 2 gallons, you'll be able to get away with a single clown goby, or maybe an equivalent tiny goby. There's a species of Neon Goby that stays a bit under an inch. And with those fish... I'd honestly just add them to the reef jar, and use the third jar for something else. As long as you stay on top of water quality, you shouldn't have any problems.

    You might consider a planted marine jar. Use maybe a tiny chunk of LR, and 1-2" of sand, and plant the jar with some caulerpa and other hardy macros. It's a unique look that I personally love.

    I've got an 800 ML jar with some Caulerpa Prolifera sitting on my windowsill with no flow or heat, and it's thriving. Hardy stuff!
    Last edited: Apr 21, 2018