Light and UV Filter

corrieberry

AC Members
Mar 8, 2009
288
0
16
London
I got a new fishy book today that had two points which helped me add to my 'wishlist', and I just want to know what people think about each one.

First is the light. In my main tank I have a 42", 26mm diameter bulb that looks yellow to the eye. Having had a look in the equipment section, they say this is 6700K which is too weak, and you ought to have 10000K. The book I have says that you ought to have something that simulates natural sunlight. In my research I've found there are 'freshwater bulbs' which bring out certain colours, and there are sun-glo (or something) bulbs which are said to simulate natural sunlight. Which one is better? I also want a bulb which is OK for low to medium level plants.

I also have an ADF tank which is a 10G and quite heavily planted, but a very small bulb (12" and 16mm, I think) with a blue bulb (oh how I wish I had saved the packaging so I knew what kind of bulb it was). If I wanted to replace it, what type should I use?

Second, do people use UV filters? They are very expensive (wish-list! Birthday coming up soon...hmmmm!) but is it worth it? I'm always looking for ways to improve my water quality (I imagine most people are!) and am just wondering if this is something that is more hype than effective? If it is worth it, what models do people recommend?
 
I believe 26mm is T8 which is not really great for growing plants. If you want to delve in to the world of the planted tank, upgrade your lighting to T5 or Powercompacts for better quality light. I tried looking but I'm not sure what size aquarium uses a 42" bulb. Is that a 55g? If so, there are tons of light fixtures that would work well for that, as its a popular sized aquarium. I just noticed you are in London, so it is possible that your tank is measured in litres which would only change the measurements of the bulbs, fixtures, etc. Do note that the higher your wpg ratio gets, the more you will need to do for your plants. Fertilizer and CO2 supplementation is mandatory for some of the more challenging plants to grow. Maintenance then increases as well, with daily fertilizer dosings, weekly water changes around 50% and trimming the plants when needed. The work is definitely worth it though IMO.

5500K is around the "temperature" of sunlight. Anything between there and 10000K will give you decent results provided you have enough light over your tank. 6500K is popular. My favorite is 9325K.

People used to use watts per gallon (wpg) as a general rule of thumb but that is slowly being phased out as more study is being put into planted tanks. For your 10g tank, a decent powercompact fixture such as this one would work well. I'm not 100% sure if they ship to the UK though.

The blue bulb you are talking about is probably an actinic of one type or another and not useful for a planted tank. You want your bulbs to be "sunlight" or "daylight" etc.

Great resources for planted tank info would be the section on AC about them, www.plantedtank.net, and www.rexgrigg.com. The latter is somewhat harsh at times, but chock full of information.

UV filters are not really necessary for tanks unless treating something such as ick or "green water." Basically they pull in water and blast it with UV light that kills anything in the water (parasites, algae, bacteria, etc.) If you have issues with these, UV lights can handle the problem real quick. They are not really needed though, save the few exceptions. I would recommend you do some hard studying on what exactly you want to do with regards to plants and then go from there.

I hope you can find something useful amongst my ramblings. Good luck and keep us posted!

-Mike
 
By the way, T8, T5, etc refers to the bulb size. T-5s and Power compact bulbs are more powerful and better for tanks requiring brighter lights
 
I've only run T8's...no problems with plant growth. And 6700K is perfectly fine. Plants honestly do not care much about the K rating, it's all based on what you think looks better. 10000K just is whiter light, that's all.

55's are marked as 48" as far as I know.

http://freshaquarium.about.com/od/lighting/l/blfixture.htm
 
Sorry. Let me correct my wording... T8 is not the most efficient way to light a tank. T5/PC are more efficient.
 
Mike & Pappy are right, 67000 are fine for plants but do look yellow to our eyes. Get a 10000k for a whiter look.

UV is definately not needed but can help in certain situations but algae etc has to be in the water column to pass the UV light. It won't help algae on plants, bacteria in fish etc. Spend your money on something else & do more water changes.
 
Maybe try a grow-light? I have two 120W Philips horticultural grow-lights on my 30G breeding tank. The ones made for green houses and regular indoor potted plants.

They are the round floodlight bulbs, because I needed that shape to fit my light housings. I think they also come in tubes that should fit into your tank's hood.

The grow lights are weighted for higher output in the red and blue parts of the light spectrum (what plants like to use the most). They give off a paler looking light, not as "bright" to the eye, so for enjoying the tank, also keep a regular daylight or incandescent - just to turn on when looking at the tank.

My plants respond really well to the grow-lights! I had a struggle getting swords to grow well with other lights, but they've taken off under the grow-lights. A bunch of anacharis has been doubling in size every week. Might be worth a shot! They are pretty inexpensive, too, compared to some of the higher end flourescent bulbs.

For UV, I'm a little biased since I have one for sale in the classifieds, LOL :D, but I basically agree with the other posts. They are awesome when you're thinking that algae might come up. Nukes it fast.

I have used mine for a few hours after every water change, after adding new fish to the tank, or just as a preventive measure. Whenever I think, you know, I've been feeding these fish frequently (fry have to eat a couple of times a day), and there are a lot of baby fry in the tank, the UV will clean up any stray nasties that may be in the water.

For a lightly-stocked tank, I think UV wouldn't hurt anything, but it would be more of a luxury purchase just to have because you want one, not critical to absolutely have "or else." LOL
 
Incandescent Gro-lights are extremely inefficient in terms of power usage. Given a watt of input a NO fluorescent(T8, T12) will produce 3x the amount of light of a Gro-light. Given the same watt a T5 HO will produce almost twice as much light as the NO fluorescents.
 
I dunno, efficiency was never one of my strong points. :D

I tried grow-lights after high output 10K flourescents just weren't doing it for my plants . . . the flourescents gave off more "bright" light, and that looked nice, but the plants weren't growing well. It was driving me nuts! $5 or $10 per plant at the store, tank full of plants, and they were dying off. I probably lost $50 of plants.

Put in the grow-lights, didn't change anything else, and they finally did well. I kept the other flourescent bulbs and just used them to replace old bulbs in other parts of the house.
 
You could try fluorescent tubes designed for plant growth. The color rendition isn't my cup of tea, but the plants will grow.
 
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