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Lighting for a high tech planted tank?

Jason Burk

Jason Burk

Member
Joined
10 Oct 2014
Messages
87
Hi there lovely people of ukaps

Ive got a 94litre Askoll XL aquarium - it comes with a 36W bulb that im hoping to replace. I am able to disconnect the lighting unit from the hood, or remove the hood of the tank alltogether, so any above tank lighting might be an option too.
- The underside of the hood where the lighting unit fits measures 26 inches
- The width of the whole aquarium is 30 inches

My problem is I dont think im getting enough light in there, its on for 8 hours a day by the way.

Im dosing EI (micro and macro) appropriately and have an injected co2 ppm of about 26, - with 2 powerheads - so ive put my problem down to poor lighting. The problem is that my plants, especially Eleocharis acicularis and Staurogyne repens just aren't growing as they should be after 4 months or so - and are - especially the eleocharis - going browish in some areas.
I also have some Aponogeton crispus red, that really isnt showing any signs of redness in the leaves - ive put all this down to poor lighting.

Anyway, what im hoping for is some lighting advice or suggestions from anyone who might have a solution for me :)
Ive had a look at some of the Arcadia J5 Pro Plant lights, I wonder of theyll be any good?

Im hoping ideally for some lighting with a better wattage, and a good PAR (Photosynthetically active radiation) level.

Thanks!
 
Your 94l is 21US gals so with 36W that's 1.7W/G so approaching high light, assuming T5. So I don't think lack if light is a problem.

You haven't stated type of light T5 etc, I assume a 36W coiled fluorescent tube type, so maybe medium light then.

Anyway the chart below from http://www.plantedtank.net/forums/showthread.php?t=105774 is a rough handy guide to light level.

PARvsDistVariousBulbs2.jpg


So even if you are in low light, your plant issues are not due to lack of light. Plenty of people have nice slow growing algae free tanks running in low light region.

I would suspect CO2 issues, where are you guessing your 26ppm CO2 from, as I suspect you are being completely mislead on your CO2 levels. What does Mr Drop Checker say? :D Does he say the same all over the tank during the lights on time ? :D
 
ian_m said:
Your 94l is 21US gals so with 36W that's 1.7W/G so approaching high light, assuming T5. So I don't think lack if light is a problem.

You haven't stated type of light T5 etc, I assume a 36W coiled fluorescent tube type, so maybe medium light then.

Anyway the chart below from http://www.plantedtank.net/forums/showthread.php?t=105774 is a rough handy guide to light level.

PARvsDistVariousBulbs2.jpg


So even if you are in low light, your plant issues are not due to lack of light. Plenty of people have nice slow growing algae free tanks running in low light region.

I would suspect CO2 issues, where are you guessing your 26ppm CO2 from, as I suspect you are being completely mislead on your CO2 levels. What does Mr Drop Checker say? :D Does he say the same all over the tank during the lights on time ? :D
Click to expand...

Hi, thankyou very much for the response and help :)
- The bulb is a dual Askoll
- Ive gotten the figure of 26ppm by using the drop checker all around the tank, and also by using the ph/kh relation chart. I have a Kh of about 5, and a Ph of 6.8

Thanks :)

ceg4048 said:
You should put your problem down to too much light and not enough CO2.

Cheers,
Click to expand...

I have only just increased the lighting, it has been on for an hour less every day for months. Also, with my co2 of about 26ppm, Ive been careful not to add too much co2 because I havent got many plants - mostly because the whole floor that isnt taken up by rocks (about 50%) is planted with eleocharis that wont start sending off shoots, so its still quite bare. And obviously with not much plants I dont want too much co2 added because the co2 levels reach around 30ppm just before lights are turned on, and levels over 30ppm are harmful to shrimp

Thanks for the response!
 
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Jason Burk said:
I have only just increased the lighting, it has been on for an hour less every day for months.
Click to expand...
No Ceg is talking about brightness, not length of time. You are providing too much light and not enough CO2 for that level of brightness. You need to improve your CO2 or more easily lower the light level.

You can reduce the light level by running one tube, putting darkened plastic sheet under the lights, removing reflectors, rotating reflectors round to block the light, putting foil strips around the tubes, raising the tubes etc.
 
Jason Burk said:
Ive gotten the figure of 26ppm by using the drop checker all around the tank, and also by using the ph/kh relation chart. I have a Kh of about 5, and a Ph of 6.8
Click to expand...
This is all an illusion. No one has any idea how much CO2 is in their tank. The DC is used strictly as a proxy which give you a general idea. CO2 distribution in a tank is not homogeneous and 90% of what you are measuring escapes the tank before it ever gets to the plants. The data from the tables always overestimates the CO2 level in the tank. Always.

Because of the toxicity of CO2 it is necessary to do a better job of distributing the flow of your filters/pumps, and as Ian mentions, you need to reduce the intensity of the light entering the tank.

People always think they need more light, when in fact they need LESS light and more CO2. Light causes algae and CO2 causes plants. So you must concentrate on finding a better way to send the CO2 that you re injecting into the plants while at the same time reducing their need for CO2 by reducing the amount of light reaching the leaves. This is a very difficult lesson for many people because they have been programmed to think just the opposite while at the same time they are being fooled by the charts.

Cheers,
 
ian_m said:
No Ceg is talking about brightness, not length of time. You are providing too much light and not enough CO2 for that level of brightness. You need to improve your CO2 or more easily lower the light level.

You can reduce the light level by running one tube, putting darkened plastic sheet under the lights, removing reflectors, rotating reflectors round to block the light, putting foil strips around the tubes, raising the tubes etc.
Click to expand...

ceg4048 said:
This is all an illusion. No one has any idea how much CO2 is in their tank. The DC is used strictly as a proxy which give you a general idea. CO2 distribution in a tank is not homogeneous and 90% of what you are measuring escapes the tank before it ever gets to the plants. The data from the tables always overestimates the CO2 level in the tank. Always.

Because of the toxicity of CO2 it is necessary to do a better job of distributing the flow of your filters/pumps, and as Ian mentions, you need to reduce the intensity of the light entering the tank.

People always think they need more light, when in fact they need LESS light and more CO2. Light causes algae and CO2 causes plants. So you must concentrate on finding a better way to send the CO2 that you re injecting into the plants while at the same time reducing their need for CO2 by reducing the amount of light reaching the leaves. This is a very difficult lesson for many people because they have been programmed to think just the opposite while at the same time they are being fooled by the charts.

Cheers,
Click to expand...

Okay, thanks

So I need to go out and get a light which isnt so intense?

Hmm, interesting, weird that because its basically the askoll stock light I'm using, youd think they would provide a less intense light wouldnt you

I'll increase the co2 as well then

Thanks :)
 
Jason Burk said:
So I need to go out and get a light which isnt so intense?
Click to expand...
No, that is not necessarily what I'm saying. What I'm saying is that you should not worship light or automatically assume that more light fixes your problems.

The object lesson is to realize that the more light intensity you have, the more CO2, nutrients and maintenance is required. Fix your CO2. Fix your flow and distribution. if you are concerned about toxicity of CO2 then you should pay much more attention to your filters flow throughput. In your opening post you mentioned nothing of this. Every paragraph was derived from a mind set of wanting more light. Do you have 10X total flow rating? Are your distribution methods excellent? Is your gas dissolution technique adequate? The timing of your CO2 is suspect. Have you performed a pH profile during the photoperiod to determine the effectiveness of the injection? This is a completely different technique than reading a single pH value and using it in the chart. Read the thread http://www.ukaps.org/forum/threads/melting-marsilea-hirsuta-staurogyne-repens.28996/ and follow the advice presented in it.

You need to pay much more attention to this and address these items. The you will see that you might be able to inject LESS CO2 and still deliver more CO2 to the plants as a result of increased efficiency. Plants grow because of CO2. Light forces them to uptake CO2 faster. Focus on gas exchange in plants instead of light and you will have fewer problems.

Cheers,
 
Okay, thankyou very much Ceg

But,
I didn't automatically assume anything, after trying for half a year to get my plant growth how I want it, I've in fact tested many of the things you've just suggested and also tried different approaches to fixing my problem, I was thinking I needed more light because of what hadn't worked previously, and also what I had been told before by many people and websites. I didn't feel It was vital that this was mentioned in my original post.

I asked the questions in order to get help, which is what you've given me and I really appreciate it Ceg.
In the future though, please try to deliver your responses - as Ian did - in a more friendly manner.
You don't need to put things like 'Every paragraph was derived from a mind set of wanting more light' its quite a rude way of examining someones question. I mean after all it was a question, if I just wanted more light id be out there trying to track down an active volcano to stick above the unit.

You're clearly more knowledgable about the topic than I am, and that knowledge as I said is really appreciated, so thankyou.. Just please don't make others feel bad because they seem to not know what to do in the situation.

Also, I quite like 'worshipping light', It passes the time

Cheers
 
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ian_m said:
Its a conspiracy between the light manufactures and plant suppliers. The excess light kills the plants forcing you to continually by more plants. :D
Click to expand...

Really? Id never heard of that before, makes sense though I guess doesn't it..

Thanks so much Ian, wish id known years ago!
 
Found a good light now
Its like the sun but better
 
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