trying to grow frogbit

[johnm]

Will a t8 8000k 15w fluor be sufficient to grow frogbit, anubias, java moss and java fern or should I use a 15w aqua-glow that came with the hood. Appreciate any help.

[pcsb23]

frogbit needs moderate to high light and nutrients in the water, it makes a very good nitrate/phosphate sponge ime. When I have used it with stronger lighting I end up throwing bucket fuls away (on the compost heap).

I don't know the spectrum of the aqua glow, so it may just be a case of suck it and see (sorry :o) if the frogbit is going to grow you will see results in a wek or so.

The annubias and mosses will be fine with almost any sort of lighting with frogbit on the top.

[johnm]

i ended up picking up an aqua rays fresh/salt fluor bulb 15w 9325k, might this do the trick?

[bs6749]

It's doubtful that the new bulb will be any better. All you changed was the temperature of the bulb (the spectrum) and it will just look different under the newer light. Plants can grow between 5,000-10,000K. What you need to look for in a good bulb is one that puts out a good number of lumens along with the spectrum of the bulb. The 15W is just how much power will be required to run the bulb. You could have a compact fluorescent bulb with more lumens and less watts needed to power it (hence it is more efficient). The compact fluorescent bulbs are in fact much more efficient. Ever notice how hot normal bulbs get? That's because a great deal of the energy used to run the bulb is wasted as heat. The CF bulbs get warm, but not hot and are much better IMO. T5 bulbs are something to look into as well. Actually I'd recommend those instead of a PC/CF setup. What size tank do you have and how long is the tank?

[johnm]

its a 40g about 24in deep. has been up and running for 3-4 yrs. Also the hood is equipted for only a single t8 bulb. i went with the aqua rays as drs foster and smith say it it good for plants with high light needs

[bs6749]

I just looked at the bulb and I wouldn't expect many positive results. It states that the 18" bulbs put out approximately 675 lumens. An equivalent would be if you hung an incandescent bulb with a rating of 50W over your tank. Actually the 50W would put out slightly more lumens (700) than the bulb you purchased. Frogbit floats, so that will help some with it being at the surface. However, your tank is really deep and if you wanted additional plants later on you would be better off going with a T5 setup as it can penetrate much further into the water with better quality light. A T5 fixture for your tank would probably run around $35-40, including the bulb.

[philip69285]

I would suggest T-5's if trying to grow out frogbit along with a not high flow rate on the surface of the tank (frogbit hates it). I actually did mine to get rid of it and push it away from light because otherwise it overgrows the tank and starves other plants of light and nutrients. My friend had gotten just a little bit of it with plants under T-5 lighting and it weeks he had a tank full and was taking large portions and throwing it away. Make sure to get bulbs with around 5000k-6700k In the Kelvin rating.... thats what does best for plants and have been proven. Higher kelvin ratings nornally burn plants that close to the surface and its not good at all (not the right spectrum either normally). I use PC on my 120gal and they do great and are 6700k bulbs. My plants thrive in it even the ones at the bottom and my tank is a good 2feet tall (past 2feet PC lose their power and are useless). In short go with a nice Nova Extreme Satalite fixture with T-5 lighting and your frogbit will do amazing. My friend had I think 6 watts per gallon. Hope this helps out a little.

[bs6749]

Anything around and above 3 watts per gallon equivalent (based on normal output bulbs) and you will want CO2 injection or supplementation with something like Flourish Excel. This may not be completely true for floating plants, which may be able to take in CO2 from the air directly through their leaves (not sure to be honest). Anything over 3 wpg equivalent and it's just a waste without CO2 as there won't be a balance in nutrients and lighting. "6 wpg" of T5's would be equivalent to about 10.5 watts per gallon of normal output bulbs and is far more than anyone would ever need. This is based on the comparison of the lumens produced per watt of each type of bulb.

[philip69285]

Well, yes I found it over kill myself for him but the proof is in the pudding as they always say. All he had was a nice plant bedding (not any of your normal brands... was bought from a plant website) Very nice stuff and the lights. No CO2 or anything else and his plants florished like no other. Now mine on the other hand I have a little over 2 watts per gallon and I have to dose with Flourish excel daily to keep them looking healthy and growing crazy. So I guess it all just depends and maybe the frogbit helped shade his other plants from the intense lighting and grew that way as well.... Not sure but the frogbit did amazingly well. I took two giant bags from him and he still had tons left. I put it in some test tanks to see how easy it is to grow and it all melted away and died within a week or 2. Was worth a try for free LOL.

[johnm]

so basically the light i have there now wont grow anything other than java? Any floating plants you can suggest?

[bs6749]

The lighting that you have right now is very minimal. You may be able to grow some crypts, mosses, and anubias. For floating plants there really aren't many that I like other than frogbit. You could say that guppy grass is a floating plant and that might do okay. I'd stay away from duckweed as it is very difficult to get rid of once you put it in the tank and it always plugs up nets and gets all over arms when doing tank maintenance. I like the idea of frogbit, you just need more light in my opinion.

[snoopy65]

The plants you have listed that you want to grow to include the frogbit can be grown in 1-2 wpg without co2 or ferts. I have all of the plants you have talked about in 1.5 wpg with no fertilizers or co2.

The bulb you have for your tank is actually less than 1/2 wpg. It will allow the java fern to stay alive but it will not give it enough light for it to grow. In order to have even low light plants flourish in your tank, you will need to add another light fixture or alter the hood you have to allow for another bulb to bring your wpg up to at least 1 wpg.

hth

[johnm]

what if the 15w was over a 10g tank? That would give it 1.5w/g with the same light. What is the difference?

[johnm]

Do you have a link for the t-5 fixture with 18" light

[snoopy65]

It is the amount of light over the whole tank. A ten gal tank is much shallower and smaller than a 40 so the light just doesn't go as far.

[bs6749]

Please measure the actual dimensions of your tank (length X width (front to back) X height). You must have really weird dimensions on a 40g tank if it is 24 inches deep and only 18 inches long. That means it's about 21 inches wide. Is the tank more of a cube than a rectangle? I don't know if I have seen an 18" T5 light so it might take some looking around to find one. The smallest I could find right now was a 24".

http://www.bigalsonline.com/BigAlsUS/ctl3684/cp18360/si1379084/cl0/coralifefwt5aqualightdoublestriplight24

[johnm]

it is a hex. I saw an 18" t5 light for saltwater, however only available in 10000k and actinic. 2x20w

[bs6749]

The 10,000K bulbs are fine, the actinics won't help the plants at all as you may already know. If you can't find the ideal 6700K bulbs you could always get two of the 10,000K bulbs.

[johnm]

would i be bettor off getting the t5 with 2x20w 10k bulbs or a single satellite compact fluor 1x40w 6700k/10k combo? all i am planning to grow are low light plants with the frogbit on top. Which lights would bring out the colors on the discus best also, orange/blue/red

[scottishbloke]

I used to grow frogbit in my 22-inch tall planted 55gallon using a Hagen T5 HO fixture (54w 6700k bulb, it puts out over 4000 lumens; I now have a double fixture as well). I started with about 3 small plants, then went away on vacation for 9 days; on my return, the surface was so thickly covered with new plants (they could have filled an entire grocery bag!) that all the light was reduced to a feeble green glow that only barely reached the bottom. For a 40g, you could try the 24'' or 36'' size fixtures, depending on the dimensions of your tank. I agree with the other posts: 6700k light is better, and frogbit is excellent at removing excess nutrients from the water column, it grows at an incredible rate in good light- too quickly even for me, and the LFS I sold it all to every month eventually stopped buying it, I was almost bankrupting them.

Just my 2 cents,

Colin