Photometer - Light Meter - Anyone used one?

Discussion in 'Saltwater Beginners' started by lorianne621, Jul 23, 2014.

  1. lorianne621

    lorianne621Valued MemberMember

    Well, I am still researching for my SW tank and learning a LOT!

    But I kind of got sidetracked when it came to lighting... I was reading how lighting became much more critical if I decided to branch out from FOWLR to REEF and I am pretty sure that I will after a year or two and I want to be sure whatever initial fixture I purchase will accommodate any future bulbs I may need.

    So I was researching the different types of lighting options and discovered how quickly the different types of tubes such as the metal halide tubes lose their efficiency. There seems to be some debate on exactly how long they keep their full lumens with some reef keepers saying they use them a couple of years and others saying they change them every 12 months or more often to be safe.

    I know I want to be safe but I also don't want to throw away a perfectly good light bulb. On the other hand, according to one article I read. If I did go with MH bulbs. Those bulbs continue to use just as much electricity even after they lose the ability to deliver the amount of lumens they did when new. So for example, if they are old enough to only be delivering 50% of the lumens, or light they did when new, they are still using the same amount of electricity to do it. Of course, I should notice if they were that dim and replace them, but would I notice at 10, 20 or even 30% if the change were gradual over time?

    So, I began to look for a way to test the lights and found out about the photometer and this youtube video..

    I can get a photometer on Amazon for under $50.00... even as low as $15 but I have not researched to see if they are good or not... I can do that later once I get some feedback here.

    I know that if this worked well it would be great for my planted tanks too and would give me peace of mind that I had used my bulbs to the end of their life span.
    Does anyone else use this kind of equipment? Or am I over thinking this?
    Surely you don't wait until the corals and other life in REEF Tanks start looking a little sad to decide if the lighting is at fault?
    Please educate me on how you know when to replace older bulbs...

    Thanks to all who are willing to share their knowledge with a newbie like me

    Blessing to you all
  2. Aquarist

    AquaristFishlore LegendMember



  3. OP

    lorianne621Valued MemberMember

    thanks for the bump... I am still interested in some feedback here.
  4. Slug

    SlugWell Known MemberMember

    I would like to piggy back on this and ask, at what % does the lighting degradation start to harm the life in the tank? Is there even a guideline for this? Maybe this is something that needs to be found out as well in addition to what you are looking for.

    Also, I would think it would help to have a water proof meter and to take readings of PAR and/or LUX from inside the water. You can't account for the true light being reflected in the water, off the walls, sand, etc if you take readings outside the tank. IMO. I think by taking readings outside of the tank will show degradation in your numbers, but I'm not sure it will be entirely accurate as to what light you are getting inside your tank. Is the glass, sand, water doing enough to compensate for that 10% loss out of the water leading to a bit longer use of the bulb? I don't know personally, just something I would ask myself when testing this.
  5. OP

    lorianne621Valued MemberMember

    I also thought about a water proof meter to test lights inside the tank... but then thought... that work has been done for us by all the reef keepers who have researched before us... we have lots of information about which lights (how many lumens) to use for which tank depths and for which corals (or plants if FW) - Also, in my research I could not find a single lux photometer that was water proof or water resistant to any depth other than just to get rained on. But if we could use a photometer to test our bulbs... say, at the 6 month mark when some reef keepers advise to throw them out and replace them and see if they really have degraded to a degree to make them detrimental to our reef tanks.
    I also thought we might be able to find out which brand of bulbs lasted longer over time... that kind of thing.
    Since I thought of it... I wondered if anyone else was doing it...
  6. Mike

    MikeFishloreAdmin Moderator Member

    Do a google search for terms like "par vs lux vs pur reef tank" and it should return some good articles. I know many reefers use the apogee meter for measuring PAR which is a more useful measurement than lux when it comes to coral growth.

  7. OP

    lorianne621Valued MemberMember

    Thanks Mike,

    I knew I could not have been the first person to think of using a meter for measuring light on an aquarium... I was just thinking of the wrong kind of meter...

    thanks for pointing me in the right direction, I will continue my research.

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