View Full Version : enough lighting????

09-01-2010, 12:27 AM
i am about to try plants again in my 150 gallon tank but not sure if i have enough lighting now. i am planning on adding a corallife life 2x96 watts to the tank. the light fixture is 36" long and the tank is 48" long and 30" deep. i hope this works bc i took down my coral reef tank for the tank. the only plants i want it there will be from the Amazon. so mainly Amazon swords

09-01-2010, 09:59 PM
Due to the depth of your tank, I would think the light levels at the bottom of the tank may be too low for swords, yet light levels would probably be enough in the upper part of the tank. The shorter length of the compact flourescents would cause the ends of your tank to be low to very low light. Keep in mind that the spectrum of light produced by the bulbs needs to be 12K or less so the actinic bulbs won't work for freshwater plants.

If you want to grow a few swords in the center of the tank the lights might work, but if you want to grow swords anywhere in the tank, I would recommend a 2 or 3 bulb HO T5 light. Catalina Aquariums has a 48 inch 2 bulb HOT5 fixture for $125, for example.

Hopefully some members with deep planted tanks can weigh in here, as my deepest tank is only 24".

Larry Bugg
09-01-2010, 10:44 PM
I agree on both counts. I have been searching for a large tank to plant the last several weeks and have intentially stayed away from anything deeper than 24". It will take a lot of light to penetrate to the substrate. Once I had the tank set up but hadn't purchased the lights yet I took two 30" lights I had and put them on the tank. Like you this left me with 12" of the tank that wasn't directly covered by the light. It was very apparent that at I wasn't getting enough light in the uncovered areas. Couple that with your debth and I think you have a problem.

09-02-2010, 09:01 AM
Seems that I have read that for that depth you need metal halide lights, which penetrate deeper into the water. Don't know personally though, as I don't have any tanks that depth, because my arms aren't long enough for that deep a tank.

09-02-2010, 12:28 PM
I think HOT5 lights are bright enough to penetrate 30" of water enough to grow sword,s as I can grow high light ground covers in a 24" deep tank, but metal halides will, of course, also work.

09-02-2010, 03:05 PM
ok. thanks for the advice. i will get an even stronger light for the tank. the 30" tank is hard to do bc the light favor and the fact i cant reach the bottom to plant anything. i have to have my brother do it bc he is so freakishly tall. i would also like to do a floating plant from the amazon that is nice. any suggestions there.

Larry Bugg
09-02-2010, 04:09 PM
You are already going to have issues getting enough light to the substrate, adding floating plants is just going to compound the issue IMO.

09-03-2010, 01:27 PM
I agree that floating plants will, not surprisingly, reduce the amount of light penetrating the water. If you decide you want floating plants, I would recommend a 4 bulb HOT5 fixture instead of a 2 or 3 bulb. Also, since floating plants have access to effectively unlimited CO2 from the atmosphere and are close to the lights, they will grow quickly and use up nutrients quickly, meaning that a regular fertilization routine becomes necessary.

Amazon frogbit is fairly easy to manage, as the plants get a couple of inches across, but you would have to thin it out every week or it will cover 100% of your tank surface within a few weeks. The dangling roots produce an interesting effect .They also are quick to show nitrogen deficiency with stunted, pale, new leaves.