Compact Fluorescents

[ddoan]

I'm thinking about retrofitting my 30 Gallon hood with compact flourescents (The spiral ones you buy from Walmart). I am looking at 4 x 13 watts in the hood or 4 x 23 watts. I will be putting in a reflector to maximize the light distribution as well.

Do plants respond well to this type of lighting? Or should I just refit with a single CF kit from www.ahsupply.com?

-Don

[TFo]

I don't have any info on the spiral bulbs, but you can't go wrong with AH Supply if you decide to order a kit.

They gave me truly awesome customer service when I upgraded my light strip a month ago. I had an unusual circumstance partially created by me that I will speak of no more. :) Suffice it to say, they hooked me up.

[adblair]

I use a compact flourescent on my small tank. It works great..... my plants are healthy and growing like mad. I would think the wattage you select would depend on the kind of plants you want to keep.

[ddoan]

I have a dollar store here that sell CF bulbs, 11 watts so I can probably shove 8 of these into the hood. I was thinking also if i needed to upgrade the lighting it would be easier since I would not have to purchase ballasts because they're built in. I was just worried on whether plant growth would be satisfactory...

[Hound]

Just a couple of questions. First do you have a 30g acrylic tank or a 29g glass? Second what sort of lighting do you have now? Third what kind of plants are you looking to grow?

[ddoan]

1. I have a 29 gallon glass tank.

2. I have 1 20 watt full spectrum fluorescent bulb

3. Looking to grow low to medium light plants

[Hound]

Ok, that's what I was thinking. Bigalsonline.com (http://www.bigalsonline.com) has 30" light strips that hold two 24" bulbs. That would give you 40 watts on a 30g which should be adequate for a variety of lower light plants. I mention it just as an option to what you are looking to do since they cost just under $40 and you won't have to spend time on labor.

[ddoan]

I also heard that CF are more efficient than regular fluorescent bulbs. With the price of electricity going up in Ontario, I want to get the most bang for my buck even if it means refitting my hood.

Plus I estimated that I can do all this for under $20 and still get more than adequate lighting and room for expansion.

[Hound]

Gotcha. Keep in mind when you have more bulbs you also have to change more of them at once. I will agree that CF are more efficient, but would say four 11 watt CF bulbs use more or less power than two 24" flourescent? Not really a question I can answer myself. Also are those 11 watt CF bulbs full spectrum? If they are then as long as they keep carrying them that will be cheaper when you need to replace bulbs.

[ddoan]

That's another thing I wanted to get at. The full spectrum concept. My gf's 10 gallon tank had two incandescent bulbs, 15 watts each. The watersprite in there grew like crazy and had to be trimmed once a week. I put in two of the 11 watt CF bulbs and growth slowed down a bit, but nonetheless there was growth. I know for a fact these bulbs are not full spectrum, but there was decent growth.

Is the fact that the CF is full spectrum or not will have any bearing? I read somewhere that the 2-3 watts/gallon rule doesn't apply well to CF because they're so efficient compared to regular fluorescents.

Hypothetically, if I go the CF route and put in 4 23 watt bulbs, that would give me 96 watts, but there is no mention whether these are full spectrum. So assuming they're not full spectrum, would I expect a decent return?

[Hound]

I have a 50g tank that is lightly planted. I seem to be doing well with a Philips plant and aquarium bulb (not sure the spectrum) and a Philips daylight deluxe bulb (6500k). That gives me 80 watts vs 50g or about 1.6 watts per gallon. I also have low to medium type plants. I believe that 40 watts of good lighting would be better than 96 watts of questionable lighting. Of course it will also help if some of the true plant experts would chime in. :) If you are looking at the screw in type flourescents I would almost think that most are of the soft white (3000k or so) variety that just won't due I don't think.

[aquabillpers]

As I understand it, the "magic" of CF bulbs is that since they are smaller. More of them will fit under a hood or reflector than can tubes.

A single 20 watt CF will not generate more light energy than a 20 watt tube, all other things being equal, not will it cost more or less to operate. It will cost a lot more to buy.

The spiral "CF" bulbs available in chain stores are not the same as those that are designed for aquarium use. They produce less useable energy. They are a lot cheaper, though.

I hope this illuminates things a bit.

Bill

[ddoan]

Isn't it true that what is stated on the CF bulb is the actual wattage unlike the tube where there is somewhat waste.

I read somewhere that on a 20 watt tube, you don't actually get the true 20 watts because of the ballast. With a CF bulb it has the ballast factored in so if it says 23 watts, then 23 watts is what you should get.

What I see is that I can get 4 x 23 watt bulbs for about $14 CAD. Some wiring and modifications and that's another $10. I'm looking at most $30.

The hood at Big Als cost roughly $40 and can have at most 40 watts with 2 tubes. I'm getting double the capacity for less.

[aquabillpers]

Hi,

Watts is a meaurement of the energy required to operate the appliance, in this case a bulb. It has nothing to do with the output of light energy. Watts is what you buy from the electric company.

However, it can be a useful guide for comparing light alternatives,
within reason. I think lux would be better, but it is not generally available.

"Full spectrum" refers to the Kelvin temperature of the light. In the tropics the noon sun is about 5500 Kelvin.

Many experts (I am not one) consider light intensity more important than the spectrum, within reasonable limits, as far as growing aquatic plants is concerned.

Bill

[Hound]

I prefer to look at light spectrum myself. Not that intensity shouldn't have anything to do with it. From my understanding a pair of 20 watt flourescents would use 40 watts plus whatever it takes to power the balast. I know Ddoan is talking about using CF rated at up to 23 watts. Four of them for a total of 92 watts if I'm keeping up to all this. He also mentioned somewhere in here electricity usage is an issue. My feeling is that if he used 2 flourescent bulbs, say a 5500k and a 6500k together he should have adequate lighting for lower light plants and keep his bills somewhat down. The four 23 watt CF bulbs by all rights should use up more energy and I would think he'd want to buy bulbs at least in the 5500k spectrum or higher. I'd hate to see what my plants would do if I stuck a pair of soft whites in my strip producing 3000k lighting or so.