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Thread: 20 gal high lighting help
10-06-2012, 02:53 AM #1
20 gal high lighting help
Hey gang. My wife and I want to have live plants in our aquarium but we have no clue what to do for lighting. We bought the tank as a starter kit and it came with a hood that had a marineland led light built in. We replaced that with a hood that has a 15 watt fluorescent bulb and added some whisteria and anacharis. But now we are reading that even that isn't enough light.. We also have a marineland hidden led light that I use for the lunar light. Would it help to use that light on the white light setting along with the 15 watt bulb? Would that be enough to keep the plants doing well? We would like to add more plants of different varieties but want to make sure they have enough light, within a tight budget. Any thoughts on what we need? Do they make a stronger fixture that will fit onto my existing hood?
P.s. sorry for the wall of text
10-06-2012, 04:35 PM #2
It depends on how much your budget is, and how involved you want to get.
In terms of lighting, plants require two things: sufficient output, and the right spectrum. Output is how intense the lighting is, often expressed in watts per gallon (WPG). (The watts refers to the total watts of high-output fluorescent bulbs above your tank; the gallons is the size of your tank in gallons, of course.) WPG isn't a perfect measure of output, but it's convenient and good enough for most purposes. Note that WPG doesn't work with LED light fixtures, which have higher light output with much lower watt rating.
The spectrum refers to the colors emitted by the bulbs. Any fluorescent bulb emits lots of different colors--reds, blues, greens, yellows, etc., each in varying amounts, depending on the bulb. The human eye sums all of these individual colors together and perceives the bulb as a single color, which is the color rating of the bulb, expressed in Kelvins (K). Bulbs that are overall "warmer" and redder are lower Kelvin, while bulbs that are overall "cooler" and bluer are higher Kelvin. So what do plants like? Plants do best under bulbs with colors of 5000-6500K, which mimics in some respects what the sun provides. However, the bulb also needs to be "full-spectrum", meaning that the individual colors emitted (not perceived by the human eye) are suitably high in specific parts of the spectrum needed and utilized by plants. These parts of the spectrum are determined by the spectral absorbance of plant pigments, chiefly chlorophyll, but others as well.
Here's my setup: I also have a 20G tall, and my hood has two high-output T5 fluorescent bulbs, each 24 watts. So, my WPG is 2.4. WPG of 1-2 is considered low, 2-3 is medium, and above 3 is high. So with a WPG of 2.4, I can grow most medium-light plants fine, but not some high-light plants. (You can find lists of low, medium, and high light plants in many places online.) The bulbs I have are from ZooMed, called Flora Sun and Ultra Sun. The Flora Sun bulb is 5000K and has a spectrum specifically designed for plants; on its own, it has a somewhat reddish/purplish color. I combine it with the Ultra Sun bulb, which is 6500K and balances it out to a more natural-looking illumination while still providing some additional lighting useful for plants.
Let's look at cost. The hood I have is this one: http://www.drsfostersmith.com/produc...m?pcatid=16770 (product number CD-29698, cost $74.99). If you want to go this route, investing in a high-quality hood for the bulbs is necessary, so expect to spend $50-100 on that. (Note: this hood also came with its own bulbs, which is good for initially saving some money; I think they're OK, but I preferred to swap them out and use the ZooMed bulbs.) If you're buying bulbs, such as the ZooMed ones, they will cost $10-20 each, depending on where you get them and the exact brand. Just be sure to get full-spectrum bulbs, 5000-6500K, even better if they specifically mention plants. Also, keep in mind bulbs wear down over time and need to be replaced every 8-12 months. The spectrum will degrade, even if it looks fine to the human eye.
You currently have 1 15-watt fluorescent bulb. That puts you at less than 1 WPG, which is decidedly low light. You would be able to grow some low light plants, like Anubias and Java fern, but not much else. I don't know the spectrum or output of your LED fixture, so I don't know what it would add, but my guess is it would not change your current situation from being a low light tank.
Oh, and one final thing. Light alone will not grow plants. But it will grow algae, and lots of it. Growing plants is all about balance. Besides light, plants will also need a nitrogen source (can be fish waste), carbon source (CO2 or similar), and various other fertilizers (phosphorus, potassium, certain metals and trace elements). All of these things need to be in balance to ensure optimal plant growth. If you add a lot of light but the other things are lacking, your plants won't grow well, and you'll just end up with a lot of algae.
10-06-2012, 05:55 PM #3
The light fixture we have now came with the perfecto hood that we bought for the tank. Do you know if that fixture you linked to would be able to be swapped out with my fixture and fit in the same place on the hood?
10-06-2012, 07:39 PM #4
Thanks for the educational post!
Thanks for all that information, Biotsrama!
I, too, have a 20-gallon-high which is currently low-to-medium light. I'm growing java ferns, anubias, one medium-sized Amazon Sword that seems to be tolerating the light well, a jungle val and some small crypts. I use Flourish Comprehensive and non-copper root tabs for ferts, and I leave the light on from 7 a.m. to 7 p.m. It's on an automatic timer, so I don't manually turn it on or off.
My research told me the type of crypts I have will take medium light. The jungle val, I'm not so sure, but I have it placed in a position in the tank where it can get the full benefit of the lighting I have. I have removed most of the floating plants so more light gets through to the bottom of the tank.
Thus far, everything is flourishing except for the jungle val. It hasn't died back; it just sits there.
Most of my plants now have leaves that are covered with diatoms, which are also on the glass, and which I (gently) scrub off with each water change.
I'm thinking of upgrading my lighting so I can have a wider variety of plants, and your information has provided exactly what I need to know, especially where the specifics are concerned! So, thanks again!
--mermaidwannabe20 gal. high: planted; 7 white cloud minnows, several RCS, 2 blue shrimp, 5 Amano shrimp, several snails; Azoo air. 65 gal: planted; 7 rosy barbs, 3 yellow glofish,, 3 zebra danios, 5 white cloud minnows, 3 dojo loaches, 6 crimson spot rainbow fish, 12 large Amano Shrimp, several snails; AC110.
10-06-2012, 08:36 PM #5
Bolsen27: I'm unsure of exactly what you're asking. Are you asking if the Nova Extreme light fixture that I linked to will fit above your tank? My answer to that is yes. Assuming your tank is a standard 20G high, its longest dimension is 24", which one of the fixtures matches. If your tank is a different length, you will have to buy a different-sized fixture, naturally. In addition to the fixture, you want a glass panel that fits underneath to separate the lights from the top of the water. The glass panel also has a hinge that lets you open it and feed your fish. I got this one, called "Versa-Top": http://www.drsfostersmith.com/produc...fm?pcatid=3790 Again, you want to select the one that's the right length, most likely 24". To summarize, the glass panel goes directly on top of the tank, then the light fixture goes on top of that.
Also, I want to clarify that the Kelvin "color rating" I referred to is technically called "color temperature". That can get confusing though since it's unrelated to physical (thermodynamic) temperature. Due to physics reasons, "color temperature" and physical temperature are both measured in Kelvins.
Mermaid: I'm glad the information is of some use. I'm not sure why your jungle val isn't taking off, while your other plants are flourishing. Jungle val's light needs are fairly undemanding. It's possible you may be missing a micronutrient, or potassium or calcium, although if your other plants are doing fine I would be cautious about changing parameters too much.
I too had a diatom problem recently; I think I solved it by doing a massive water change, then running Seachem PhosGuard in the filter for a few days to remove silicates, before resuming dosing with phosphate.
10-06-2012, 10:24 PM #6
I bought a marineland 20 gallon high, and am still using the light that came with it. for the most part it works well with plants. just not high demand plants, such as dwarf baby tears, or any red/purple plants.
current list of whats in there:
Riccia riccia fluitans.
not the most demanding plants, but with a bit of ferts they are all doing increadibly well, in fact the anubias just flowered.
you can try a "Life-Glo Fluorescent Bulb, 15 Watt, 18 Inches" as i have heard good things, its in-expensive and will fit the fixture that comes with it. (check the inches req should be written on the bulb that came with the tank.
Basicly my point is this. with what you currently have, you can have a fully planted, carpetted tank, that will look great, it just takes some determination, a bit of fert, and trying out several plants to see which ones thrive and which die off. though you will be limited to what plants you can have, it is an option that will save you some money.
Just my 2 cents
10-07-2012, 12:07 AM #7
Biotsrama: I bought a glass canopy tonight. And I am looking into buying a new light fixture. I was researching the one you have and found somewhere on these forums where someone said that particular fixture would make a 20gal high tank into a high lighting tank and that i would be forced to inject Co2. I linked a quote to his response which was in response to a question which had a link to your fixture and asked about having to inject Co2
Originally Posted by MCHRKiller
Basically I am ready to buy a new fixture I am just not sure which route to go.
10-07-2012, 02:02 AM #8
I think I am leaning toward that nova extreme slr 48 watt t5 and getting the zoo med bulbs like you have (flora sun and ultra sun)
10-07-2012, 02:43 AM #9
The point about CO2 injection is valid. As I mentioned earlier, lighting is just one piece of the puzzle, and all plant needs should be in balance or you will have problems. Personally, I don't think 48W of T5HO lighting over a 20G high tank necessarily makes it a high-light tank, nor will you be "forced" to inject CO2. I have never injected CO2 in my setup. However, it's true that I have battled various forms of algae in the past (fortunately it is now under control), and currently I regularly dose Seachem Flourish Excel, which is an alternative carbon source to CO2.
Again, it depends on how much time, effort, and money you want to spend, and what kind of results and plants you want to have. Are you OK with buying Flourish Excel (as well as other fertilizers) and dosing it regularly, AND do you want to grow plants that have higher light demands? If so, go with the 48W setup. If your goal is lower money/effort (lower tech) and less demanding plants, consider a lower light setup.
One other point: If you do get the 48W setup and find it's too much light, but don't want to inject CO2, you can get floating plants that grow at the surface (duckweed, water lettuce, and others). These will reduce the amount of light that reaches the tank bottom, helping to curb algae growth and giving plants down there more of an equal footing. At the same time, plants that float at the surface can utilize CO2 directly from the atmosphere, and thus won't be CO2-limited.
10-07-2012, 03:54 AM #10
Thanks for all the info! I'm gonna order the nova extreme now.