light question...

Edicson · 01-27-2010, 03:20 PM

I have been looking for a 60w 36" lightstrip. i was told that they dont come in 60w, that the most they come in is 30w. now my question is, if i get a 30w light strip that holds two bulbs, as far as plants are concerned, does this count as a 60w light?

peanutbowl · 01-27-2010, 04:47 PM

In a word, Yes. Check out the fishneedit lights. These T5 fixtures seem to be the best deal on the market and anyone I've talked to that uses them, love 'em. Also, one thing to consider is to perhaps get a 4 bulb fixture and either only use two bulbs for the whole photoperiod or use all four for a short 3 to 5 hour burst. Spacing two bulbs out in the fixture will give you better light spread in the tank and less of a "hot spot" in the middle. The ho t5's that come with the fixture are 39 watts each and can be replaced with normal output bulbs if you want to back off the wattage a little.

Do you plan on using pressurized CO2?

Edicson · 01-28-2010, 01:59 PM

no, no co2. i plan on keeping my tank low tech. thats why i want to go with 60w (2w per gallon), which brings me to another question, if i use 2x39w bulbs(78w) does that bring me to strong light (over 2w per gallon)? in other words, would i need to use co2 injection at that point?
i looked at the T5-ho 3ft 2 lamps and it is much cheaper than the one in stores.
1 more thing....if i do go with using two bulbs, should they both be white, or should i go 1 white 1 blue(i read somewhere that blue stimulates plant growth, if i remember corectly)

peanutbowl · 01-29-2010, 08:59 PM

Quote:

no, no co2. i plan on keeping my tank low tech. thats why i want to go with 60w (2w per gallon), which brings me to another question, if i use 2x39w bulbs(78w) does that bring me to strong light (over 2w per gallon)? in other words, would i need to use co2 injection at that point?

That wattage with t5's is going to put you into the higher light range. CO2 isn't absolutely needed but will be easier and cheaper in the long run than excel. You'll need a carbon source for sure. IMO, pressurized will help keep the tank more stable. The "watts per gallon" rule was developed a long time ago when t12 fixtures (shop lights) were the norm for lighting tanks. t5's are a lot more efficient and produce a considerably higher amount of PAR (photosyntheticly active radiation.) 50-100 moles/sec at the substrate is considered the difference between low and high light nowadays, though without a PAR meter to take a reading that is not of much help.

Quote:

1 more thing....if i do go with using two bulbs, should they both be white, or should i go 1 white 1 blue(i read somewhere that blue stimulates plant growth, if i remember corectly)

You will have to experiment with different colors to see what YOU like. Plants respond to light in the visible spectrum and are very adaptive to what's available, just like in nature. Plants contain more than one type of chlorophyll, each of which respond to different wavelengths of light. So where there may be a shortage of say chlorophyll b due to a lack of bluer wavelengths, there will be more chlorophyll a present and responding to redder light. There has been some research that suggests plants grow more "stemmy" and long under red light and more compact under blue light. As long as you stick with bulbs that are in the range of 5000 kelvin and 10000 Kelvin, you will provide energy for photosynthesis. Many will suggest 6500 kelvin bulbs for plant growth, but they tend to be really green IMO.

freckles · 02-03-2010, 08:57 PM

I have a Plant Bulb that I use for light on my 1 aquarium Plant

How long does it need to be on ?

I was wondering

Jay · 02-19-2010, 03:22 PM

Quote:

That wattage with t5's is going to put you into the higher light range. CO2 isn't absolutely needed but will be easier and cheaper in the long run than excel.

I agree with peanut, carbon is going to be essential at the higher light. There is only about 5ppm of C02 available in aquarium water far short of what is needed by plants under high light.

Hey Freckles...a little more info about the tank...size etc. would help

Jay

Donabate Gav · 02-21-2010, 03:03 PM

Quote:

Originally Posted by peanutbowl

The "watts per gallon" rule was developed a long time ago when t12 fixtures (shop lights) were the norm for lighting tanks. t5's are a lot more efficient and produce a considerably higher amount of PAR (photosyntheticly active radiation.)

This is interesting. I have a Fluval 190 (L) tank which I think equates to 50 US gal - I'm in Ireland. The light hood has 2 x T5 strips which are rated 24watt which is precisely half the 2 w per gal rule. On the basis that lighting is more efficient now do you think this is ok for a planted tank? Would it be possible to put higher wattage bulbs into the hood? I assume Fluval know what they are doing even if I don't!

I have just gotten rid of Ciclids in favour of more peaceful Tetras (Neon x 10 plus Pristella x 5) and one Common Pleco to start with.

My current lights are 24 months old so need to be changed any way. I am also going to give a DIY CO2 system a go in the next couple of weeks.

Any thoughts would be helpful please.

Jay · 02-21-2010, 06:45 PM

I am not familiar with that light fixture, but my instinct tells me that you may be a tad light (no pun intended

) on the PAR or WPG for us old timers. You can always experiment with low light plants like "Anubis sp" and see what happens.

IME I think a diy CO2 setup is going to be hard pressed to provide adequate CO2. That said, under minimum light, it will not hurt you. Under high light and a good nutrient dosing program a diy will cause you a world of problems in a tank that size.

Jay