Emersed growth lighting

The friendliest place on the web for anyone with an interest in aquariums or fish keeping!
If you have answers, please help by responding to the unanswered posts.

fish_4_all

Aquarium Advice Addict
Joined
Mar 13, 2005
Messages
1,864
Location
Aberdeen, WA
Does anyone have any information as to how muchlight certain plants need when grown emersed? I am really beginning to think that lighting plays almost as much of a role in emersed as it does for submerged. Some plants like Anubias probably only need minimul light, let's call minimul 5 watts per swuare foot just for a reference. I would then think that a plant like Bacopa Australis may need 10 watts per sq.ft. That would lead to a plant like HC possibly needing up to 20 watts per sq.ft. I know this is all guess work but is the best way I could put it to get my point across.

The real question is, those that have emersed setups, how many watts are you using, how far away from the setup is it, what is the dimensions of the setup and maybe even the dimensions of the lighting would be helpful. I think we can get something figured out that will help others to grow emersed plants without the normal failure rate associated with first attempts.
 
Well, we all know that light intensity is a function of the distance between the source and the plant. Air has much less affect on lowering the light intensity, but more importantly algae really is at a disadvantage for growing, so even minor deficiencies won't be as damaging. CO2 will also likely be in a much more consistent and higher level, which helps in that aspect as well. Light level is normally the least important thing with growing plants, that is it is truly the perfect limiting reagent. Not enough light and the plant shuts down, choose any other growth factor and you get seriously bad results.

I'm on a lawn care/gardening forum and always tell them, "you think this is tough, try growing plants under water!". :D
 
All too true. I know i can grow plants in the sun and in a fish tank but taking them from a fish tank to emersed has just baffled me. Again though I was using only 25 watts to light an entire black seedling tray and it wasn't the best quality. I do see a lot of setups that use alot more light that I do and of course have much better sucess than I do. I guess I will just have to get a setup with more light and see if it makes a difference with all of the other things I am going to try that may be the true effect on my success.
 
fish_4_all said:
All too true. I know i can grow plants in the sun and in a fish tank but taking them from a fish tank to emersed has just baffled me. Again though I was using only 25 watts to light an entire black seedling tray and it wasn't the best quality. I do see a lot of setups that use alot more light that I do and of course have much better sucess than I do. I guess I will just have to get a setup with more light and see if it makes a difference with all of the other things I am going to try that may be the true effect on my success.

What is the quality of the light? How old is the light? You might just be using a bulb that is no longer outputting the proper wavelengths of light. The other thing is most emersed setups keep near 100% humidity as these plants are aquatics and do require moisture to keep the leaves from drying out. When you tried this before was it open air or sealed well enough that it was very moist?
 
No clue how old the fixture was but the bulb was newer, about 6 months worth of use on it from when I got it. The fixture on the other hand was well over 5 years old and could be the cause. The containers were show boxes with clear plasitc vinyl lids and there was always condensation on the top so I think it had plenty of humidity. All of them were air tight and air was allowed in for daily.

My HC never did anything more than melt except for a couple ittle spots that would grow a little then turn yellow. My crypts turned to mush, Wendtii and Lucens. Wisteria always melted and turned to brown goo as did most of other stem plants I tried.

I was using Shultz Aquatic soil and adding tank water that had EI dosing to it the day beofre a water change so there was a lot of nutirents but not a full dose.
 
fish_4_all said:
No clue how old the fixture was but the bulb was newer, about 6 months worth of use on it from when I got it. The fixture on the other hand was well over 5 years old and could be the cause. The containers were show boxes with clear plasitc vinyl lids and there was always condensation on the top so I think it had plenty of humidity. All of them were air tight and air was allowed in for daily.

My HC never did anything more than melt except for a couple ittle spots that would grow a little then turn yellow. My crypts turned to mush, Wendtii and Lucens. Wisteria always melted and turned to brown goo as did most of other stem plants I tried.

I was using Shultz Aquatic soil and adding tank water that had EI dosing to it the day beofre a water change so there was a lot of nutirents but not a full dose.

You seemed to have done everything right? 8O
 
The only thing I can think of was the lighting and how far away it was but it was only 8-10 inches. I even had the HC much closer than that. I did find that I can grow HC floating in my tank. I never thought it would because it wants a nutrient rich substrate but at least it grows for me.

That is why I have decided to try and grow the plants from submerged to emersed letting them grow right out the top of the tank and placing them on some egg crate to support the plant structure. I figured since I can grow floaitng plants I might have better luck just letting them grow right out the top. The only problem I have been dealing with is how to provide enough humidity to keep the tops from turning brown and crispy without blocking light.

Oh well, sooner or later I will figure it out and also figure out what way i can actually grow emersed plants. I really want them to flower and go to seed but I have to get them to grow first.
 
I'm currently just using natural sunlight from a window that is excellant for growing African Violets. I get slow but good growth.

Most commonly I see it suggested to just use a double shoplight fixture over emersed setup. Should be plenty of light for most plants. Just like in the aquarium the bulbs should probably be changed every 6-9 months.

I've found that about 1/3 of my crypts will melt at least a bit when moved to the emersed setup. Of these, only two melted and never came back. If the rhizome is still firm, you can try floating it in your aquarium until it startes getting leaves and roots again. Once it's got 2-3 leaves you can try moving it back to your emersed setup.

You might try having a lid that isn't quite as tight next time. When I was setting mine up I was told not to go for a perfect fit as a little bit of air movement is a good thing and it will help prevent it from getting too humid. You also need to avoid cooking the plants with too much sunlight.
 
Back
Top Bottom