'Splain me lighting options please

hollyfish2000

hollyfish2000

Members
I confess that I still don't quite "get" which bulbs are best for planted tanks. Am going to try -- again -- a low-light set-up. I'm really good at high light/co2, but don't want to do that.

So looking at new fixtures and am confused.

Is 10K daylight a suitable bulb for a planted tank?
What about 12K super dayllight?
Or should I only use specific plant grow type bulbs?
Do actinic provide anything of value to plants?

thank you!!!
 
L

ltrepeter2000

Members
The 10K and 12K would need to be used for very limited amounts of time if you are going for a low light setup. Usually "low light" means standard aquarium fixture with a T8 bulb. You would be best off going lower on the Kelvin scale if your goal is low light. Definitely below 6700K. Actinic do not do much for plants as the light is pretty far beyond what plants utilize. What kind of light fixture are you planning to use? If its compact fluorescent, than a 5400 or 6700 bulb would probably be best.
 
hollyfish2000

hollyfish2000

Members
Fixture is a Deep Blue T5 HO with two bulbs of 39 watts; it comes with a 10K and an actinic.

For a low light to moderate-light set up (vals, crypts, anubias) what light bulbs would work best?
 
Andrewtfw

Andrewtfw

Global Moderators
Low light generally refers to under two watts of light per gallon, and is a very basic way of estimating the correct amount of light without getting into lux and PAR. Color spectrum of the bulb, so long as it is not actinic, has more to do with what is pleasing to the eye than in terms of actual plant growth. Actinic has a color spectrum that is far too much in the blue/green range and not enough in the yellow/red range for plants to benefit.
The fixture you have is a "high output" T5 fixture. You could certainly do lower light demanding plants with this fixture, but you will not want to run both bulbs. The hight of the tank also comes in to play here. Assuming that this is your 40 breeder, a little light will go a longer way than in a taller tank. Since there are almost no t5HO bulbs in the 8k spectrum available in the US, I would personally reccomend one of the following: Power Glo or Life Glo (both by Hagen) or Flora Sun or Ultra Sun (both by Zoomed). Again, you will only need one bulb.
 
hollyfish2000

hollyfish2000

Members
Thank you all!

I'm now rethinking and cancelled the order for the light I was thinking about and for which I'd need new bulbs. Currently, I have a Coralife powercompact on the tank. One bulb is actinic (I use it like moonlights) and one is a 6700 96 watt (might be 98).

So if I just use this one bulb with the light about 2" above a 40 breeder, I'm in a low to medium place, I think . . .

Tony -- I"m trying to duplicate your 45 tank with the nice anubias growth and no algae.

I'm thinking not to put the light on for too long -- maybe six hours? Should I dose with Excel just for giggles?

I have anubias, java fern, vals and crypts. I do have two small swords. If they don't do well, I can move them to my other planted tank. I may get a few more crypts to found out the foreground.

Any thoughts on this new plan??
 
Andrewtfw

Andrewtfw

Global Moderators
Holly,
I am currently running one 65w pc bulb on top of a 29 gallon. The tank has a glass top, so some of the color spectrum is being lost due to diffusing through the glass and then through the water. Regardless, I have a flame sword that is growing just fine and a bunch of anubias that is also doing well. Being that a 29 is much taller than a 40b, I think one pc bulb will certainly be adequate for what you want to accomplish.

I dose with excel and have noticed a difference in terms of algae reduction and plant growth. Planted tanks usually have a photo-period of 8-10 hours per day. That being the case, I would start at 8 hours and cut back as needed.

You may also want to get a sample of Tony's water and test it for phosphates and nitrates. My guess is that if he has a lot of plants in the tank, and changes water like he does on his other tanks, both levels are low.
 
hollyfish2000

hollyfish2000

Members
Good point. This PC light is also through glass . . . I'll boost up to the hours a bit and see what happens. Can dose with Excel as it won't hurt anything. Don't really care about growth, just want stuff to live and fight off algae. My water changes are probably similar to Tony and water is probably also the same source (as we live three blocks from each other).
 
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