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Discussion Starter · #1 ·
More evidence against using too much light in an aquarium

I have been at 3.5 WPG and have fought algae and burned leaves - even on plants that are listed as "requires high light"

So, one of my 2x65 W ballasts went out on my 4x65 W orbit. I ordered a new ballast, but while I was waiting I didnt want my delicate plants to die off due to the reduced ligh. To help out, I moved the 56W (2x28W) T-5 fixture from my Mbuna tank to join the 2x65 W ballast that was still working on my orbit light over the planted tank.

This gave me 186W over a 75G tank.

The result - MUCH better and faster growth.

By better I mean that the leaves are stronger, brighter, and much less curled. The biggest difference has been with R. Macranda, L. Aromatica, Star Grass. These plants were doing fine in at 3.5 WPG, but are just exploding at 2.5 WPG.

The only plant that looked better before was Cabomba - which is kind of stringy under the lower light.

SO - what to do?????

The answer - I am going to keep one 2x65 ballast dark over my planted tank, and buy another 56W fixture to replace the one over my mbuna tank. Not an elegant solution, but the 56W fixtures are only $50.

Now I only wish I hadnt spent $50 to replace the broken ballast ;)
 

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This would only be evidence if you had the same k bulbs of the same age and the same reflectors.

There are so many variable in your "evidence" that it really means nothing at all.
 

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we had a thread a while back where it was discussed how as tanks get larger, the WPG requirement actually goes down. besides, I'd rather have a little elbow room of extra light as the compact bulbs dim with age. I suppose for your tank it would be best to run it 2x65 all day, but only 4x65 a few hours midday.
 

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Discussion Starter · #5 ·
This would only be evidence if you had the same k bulbs of the same age and the same reflectors.

There are so many variable in your "evidence" that it really means nothing at all.
Rex - I said "evidence" not proof
 

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From Wikipedia

Evidence in its broadest sense, refers to anything that is used to determine or demonstrate the truth of an assertion. Philosophically, evidence can include propositions which are presumed to be true used in support of other propositions that are presumed to be falsifiable. The term has specialized meanings when used with respect to specific fields, such as policy, scientific research, criminal investigations, and legal discourse.
It's not evidence. It's anecdotal at best.
 

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Now it's become a philosophy class, what is truth?


Let's ask a few basic questions.


Spypet said:

as tanks get larger, the WPG requirement actually goes down
The question is __why__ that might be(or not).
While folks enjoy saying stuff, they often take many things for granted and make a lot of assumptions.
We all do it to some degree.

Now about the observation, does good CO2 drive light efficicay, or does more light drive more CO2 uptake and demand?

Basically, was it the light, or was it something else like good stable nutrients/CO2 etc?

I have high light tanks, I can grow things very well in them also.........
So the observation byself itself does not appear to match the observations to me.

You could many things about high light causing X, Y and Z.
Does not mean it's right.

I can have everything in good shape light and nutrient wise, but have a poor CO2 level and have a messed up tank, but many assumed that the high
2.0 ppm of PO4 was causing the algae, not the CO2.

So is it really the light causing the problem?
I do not think so.

Will less light be easier for more folks to manage?
Definitely.

It's easier to hit targets and balance a tank, it's more forgiving, as any method is, with less light(to a point, which tends to be fairly low).

I'm all for low light CO2 enriched tanks or non CO2 tanks, but it's far more powerful to know why a tank does well in a high light, med light and low light situations/treatments.

Knowing how to master each method allows you to better analyze and predict patterns, issues and set up and design test to rule things out.
It's not the method's fault, it's your fault, the method works fine, your ability to balance things and compare them to other systems is quite another matter.

Many face this issue when they add more light, they assume more is better, not really. They had a nice easy to maintain tank, they decide they can have the super tank etc and things will be much better, no, they are just faster and harder to balance.

While such questions and test methods do not really get a pure truth, nothing will really, it is still very very useful and works dang well.

Regards,
Tom Barr
 

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That's very interesting evidence pbohart, something that definitely warrants further research and experimentation.

Some of what's been discussed over at APC has hypothesized that in the traditional "triangle" - light, CO2, and nutrients - light is basically the engine driving growth, and it's possible to drive growth past its physical limits of absorption of certain nutrients (such as calcium), at least within specific species. So while you might have more than enough CO2 as well as micro and macro nutrients, if the lighting is too high, you could actually start to see certain deficiencies in certain plant species (such as calcium deficiency).

In my humble opinion I look at it as a sound working hypothesis.
 

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Anecdotal evidence derived from watching plant growth in your aquarium and the conditions associated with poor vs. good growth is certainly evidence. While anecdotal evidence may not hold the same persuasive power as scientific evidence, controlled experiments in aquariums of the sort that we are probably all interested in are rare.

In my observation of algae-related posts on this forum (not a scientific study, of course), folks with "too low" light often have problems, but so do people with "too high" light. The "too high" people, as Hypancistrus said, seem to develop problems when their fert regime and/or their CO2 can't keep up with their high tech lighting. It is undoubtedly more difficult to balance things in a high tech aquarium.

Before the OP made this observation, it seemed like moderate light had advantages over high light in tanks because of a reduced likelihood of algae. I hadn't thought that some plants might actually grow better (even in the absence of algae) with less light. I'm interested in other thoughts or experiences with this issue.

Karla
 

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So is it really the light causing the problem?
I do not think so.
It is not about how many nutrients we can throw at the light, but using the light to grow nice healthy plants, it does not take massive amount's of electric sunshine to do that.
To many problem are associated with using to much.

Aquatic plants in the wild do not get blazing sunshine 10/12 hrs a day 7 a week.

The best way I know how to tell people to grow healthy algae free plants is to reduce the lighting, Tom, not throw more stuff into the tank, some folks just need to slow it down a bit so they can see how the plants respond, not add more frustration on them by telling them to add more of this and that.
Once they see how the plants do in a reduced environment then they can begin to experiment with a little more lumens if they so chose.... eh

I know it can be frustating, I have been there.
I as many others here on the forum appreciate your involvement.
 

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I am thinking of reducing the light on my 45 gallon tank from 110 to 72 watts, just to get a slower process going. I note that the 110 watts, when I had it on a 29 gallon tank, led to lots of algae problems that seemed to pop up overnight. But, on the 45 gallon tank it takes a couple of nights:hihi: So, my logic is that a 72 watt intensity might allow me the working room I want.

The anecdotal evidence of this thread is encouraging me:biggrin:
 

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You guys are missing ther point, plants in natural systems do get blazing sunshine, about 4 to 10X the highest lighting most aquarist ever keep.
Most aquatic plants grow out in marshes, along river banks where they get full sunshine, they also grow underwater in deep sections with lower light.

In tropical systems they have higher light from about 1 hour after sun rise till 1-2 hours till sunset, or about 10 hours based on a 12 hour day average(which is the tropical standard). Buy a PAR light meter if you don't believe me and go there and measure it. I have. I did niot enjoy being there at 5 am till noon taking measurements every 15 min:angryfire

I do not see anyone actually giving any sort of light quantities here.
Talking about too much, too little etc without testing/quantifying any sort of measure for that seems a little bit running blind.:proud:

Some believe it's Ca, or other practical physiological limits that make a tank with say, 5-8 watts/gal, an issue.

You discuss the plant's ability itself, not the issue of management (our ability to keep up). Those are two different issues.
This was discussed many years ago, long before this site, APC etc was even around.

It's not the plant's fault, it's our fault.
I guess some like to blame plants for their issues in horticulture?
It seems like an impossible feat till you learn how, just like riding a bike was before you learned how. Years ago we assumed that we just could not grow certain plants that today we have no issues with at all, growing plants submersed seems impossible for many aquarist and has for many years till the last 10-20 years.

I have no issue growing plants at 5.5 w/gal, or 450 micromols of lighting, I have an easier time maintaining things at 220 micromols of light though.
One client has 800 micromols of lighting, plants grow like weeds. Again, takes more work, but it's far from impossible and the plants have show no physiological limitations of any sort........
That's far more light than anyone on any list I've seen yet. No Ca issues etc.

But in both cases, it's not the plant's fault, nor the method or internal physiology of the plant, it's my own fault and trade off.
More light = more work= more growth etc if things are kept up on.
Managament issue, not a plant issue.

The lower end is an interesting area.
CO2 allows you to grow plants even lower.
Good nutrients as well.

Lower light allows much more flexibility for our habits and abilities, methods, nutrient locations, nutrient levels etc, than higher lighting.

But there is that drop off point, shading issues also, we want some growth, more managable growth etc, but not hardly any growth or slow death due to not enough light.

I've grown Gloss fairly well at 25 micro mols, Hydrilla will grow at 1/2 that, 12 micro mols.

I grew pearl weed at 54 w (PC lighting) /60 gal cube tank 24" depth quite well using CO2 and little ferts +fish waste.

Most plants do pretty well at 100 micromols (about what folks used 10 or more years ago, 2 w/gal ranges using T12 FL's), only a very few plants may, and stress the may part, appear to need more to be healthy looking.
The CO2/nutrient issue and adapting to a stable lower light,good CO2/nutrient regime is critical when looking and isolating one treatment like lighting.

Aquarist most certainly can do it, but they will want to make sure and try and rule out alternative issues like the nutrients/CO2/start with a stable system prior etc. You need to have some degree of control and the method/ability to make a measurement.

Light meters are much cheaper these days than in the past, PAR meters from Apogee are fairly reasonable.

If you are going to do any research, even if it's non scienctific/pilot study, you will need a way to measure the light consistently and with respect to the plant's needs/demand. That way you can find and measure the min light with a wide range of lighting types and the predictive valve is extremely high when approaches this way.

That is rather obvious and many enjoy speculating about lighting...... without ever trying to measure it:icon_idea

How many on this list or elsewhere have ever even used a PAR meter?
Define low light or high light. What quantative measure is low light?
I'd say 25-80 mic mols. Med light 80-180, High light 180-350. VHL, 350-500, Extremely high light: 500 and above.

Regards,
Tom Barr
 

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I think both Wö£fëñxXx and Tom Barr present two sides of the "balancing your tank" discussion.

To pbohart, your problem was that your tank wasn't really balanced to start with. To fix it, you had two options:

1) Add more fertilizers/nutrients & CO2 to your tank. <- Tom's take on this.
2) Reduce lighting so that the existing nutrients and CO2 you have are now sufficient to support the amount of light you have. <- Wö£fëñxXx's view.

Since you had no choice and fate decided to burn out one of you ballasts, you took the second route and noticed better growth.

Lots of people out there, me included when I just started out, think that "more is better...more lights!" and are hesitant to believe that using less lights and using a shorter photoperiod could actually be better for plant growth. So that's where Tom's argument comes in...

I actually kept the lighting I had, pumped up my EI dosing and my CO2, noted great growth...and also noted my trimmings went from once every two weeks to once every week and this tired me out. I then cut my lighting in half and dropped the photoperiod. Now I trim once every two weeks and everything is working out nicely. =)
 

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Its "whatever works for you" is the lesson here. George Booth has never advocated more than 2 watts per gallon, but he also advocates much lower C02 levels than you do Tom, and he is also the only person in America still pushing substrate heating cables and the Dupla "Ten Golden Rules" I don't think his WEB site has changed in ten years, and if you have not been in the hobby for more than 8 years, you have never heard of George Booth.


Most aquatic plants grow out in marshes, along river banks where they get full sunshine, they also grow underwater in deep sections with lower light.
The majority of the plants we use grow in very shallow water, most six inches or less, a foot at the most. Very few grow totally submersed, and most grow above water or across the surface. So, yes, many grow under full sun, but also under much less water which diffuses the light. This is why some plants struggle more without more intensive light. Glossostigma grows like gangbusters in 12" or less depth, but in a depth of 30" it needs MUCH more light
 

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I took the in between route. When I first started my 20 gallon, I had my 65W PC light right on the glass top and DIY CO2. I started having algae problems as the plant grew. I got bulk ferts. I started having algae problems again. I took a suggestion to raise the light on legs. Algae problem lessened to a manageable level. I went pressurized, and now, my tank is finally very low maintenance except bi-weekly prunings.

So as others have said, the answer is balance, but it's the path to get to that balance that is different for each person.
 

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Its "whatever works for you" is the lesson here. George Booth has never advocated more than 2 watts per gallon, but he also advocates much lower C02 levels than you do Tom.
True, I used more light(3.8 w.gal at the time) and found I had less issues with most species using more gas, the idea George suggested was higher CO2 was bad, 10-15ppm was the standard 10 years ago, although many Germans and others had long suggested 40ppm or more as deterimental to fish, while helping to improve plant growth.

My advocation of using more CO2 was based on experience with higher light, assuming that the higher light, higher uptake rates of CO2/nutrients would be useful applied to lower light tanks, essentially providing much more wiggle room for those parameters.

This proved to be very useful and shows a fairly simple concept in high vs low light tanks and gradations in between, more light= more CO2 uptake, more nutrient uptake/demand.

That's a fairly easy concept to understand.

But many folks think more light is better:angryfire

The majority of the plants we use grow in very shallow water, most six inches or less, a foot at the most. Very few grow totally submersed, and most grow above water or across the surface. So, yes, many grow under full sun, but also under much less water which diffuses the light. This is why some plants struggle more without more intensive light. Glossostigma grows like gangbusters in 12" or less depth, but in a depth of 30" it needs MUCH more light
Very true. I wish more would realize that.
Amano seems to suggest otherwise, I know aquatic plants in natural system and what's been said by him is not correct, I've done that work(not particularly fun either) in the field in marshes, venral pools and forest swamps. I think he might say this to get folks to use less light, so the goal to use less light is for the right reason, even if the advice's reasoning is wrong.

About Gloss: I grow it at 25 micmols of light in 28 inch deep water, it grows slower, but nicely manageable (tank had about 1.5 w/gal). Jeff grew it with 15w on a 10 gal 16" High tank quite well. Steve grew it wonderfully with 2w/gal in the 24" deep tank. Not many folks have 30" deep tanks or more.
I'd call it a lower light plant really, does very well at those lower ends.
HC is less light tolerant by comparison.
I have not pushed the limits, but I'd say 50-80 mic mols is it's limit.
But that's more of a guess.

So does Gloss really need much more light, or is the rate of growth always assumed to be best when it grows like gangbusters?
I do not care for fast Gloss growth personally, and over time few do.

Using less light to control growth is the best option as it downregulates CO2 uptake and nutrients uptake. It also means less light for algae.

So if you like less CO2 for some reason, that will help, if you like fish waste only for nutrients, that will help, if you like substrate ferts only that will help, if you prefer to run the tank nutrient lean, then this will help , if you do not like CO2, then this will help.

If you go the other way, adding more light, management options become increasing limited, but you find what the optimal ranges at high growth rates this way, then that information is useful for maxmizing the lower light tanks as well.

When we want more mangable growth, more wiggle room for whatever method we use, less lighting is most often the best method to reduce growth rates/ nutrients/CO2 demand.

You can use plastic sheeting and scuff them up with sand paper etc to various degrees to reduce the light on many hoods, the plastic is relatively cheap, get plastic that can handle the heat without melting etc.

I can reduce the light intensity by 50% pretty easily this way and have the PAR meter to check and make sure I'm not below 25-50 mic mols.

Algae management is also much easier and methods for removal are much more successful. Larger tanks have less light for this reason, management of growth and reduced algae issues, as well as angles of strike on the leaves of the plants. There's more diffusion of the light in larger tanks as well in nature.
the sun moves around, our lights really do not unless you use the dawn to dusk patterns etc with a series of lights or use a tracking motorized light bar.


Regards,
Tom Barr
 

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wow what a great thread. im a newb but this has shown me some insight as to how the 'triangle' works. thanks guys. a good read that was!
 

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I think Karen Randall has a nice diagram(or other folks) that uses 3 circles, one nutrients, one light and one CO2.

Balancing Lights, CO2 and Fertilization

Basically if you have 3 elements meet in the middle, you will have good growth, if you neglect any one or combination, they will cause issues.

It's not on/off, black and white either, there are definitely gradations as you move away from optimal ranges. Less wiggle room as it were.

My generalized advice focuses on getting as close to that optimal range for each as possible, then varying one element to see what type of response it produces.

Lighting is great because you can do so many things with it and it's relatively easy to work with.

I often suggest an optimal range where a parameter will be most effective.
It's not a discrete point and is slightly different for each organism.

Lighting has a pretty wide range that's optimal, but it might not be so optimal for us if we prefer slower manageable growth.

A little patience can be very rewarding and last a lot longer than the full blast higher light methods. Removing the CO2 next allows even less work.

I think folks should try more lower light CO2 or go non CO2 and see. You can keep the high light CO2 tank and have the other's less maintenance, which reduces the work load but you can still play with the high light.

Regards,
Tom Barr
 

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I think folks should try more lower light CO2 or go non CO2 and see. You can keep the high light CO2 tank and have the other's less maintenance, which reduces the work load but you can still play with the high light.

Regards,
Tom Barr
This is great advice, Tom. Some of the most fun tanks are a non CO2 tank that's balanced - that every once in a while you toss in a little trace or some Excel.:proud: You don't even need to be super regular on water changes. If its balanced with a lighter fish load.
 
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