High light vs Low Light?

[John N.]

I'm not sure if you were like me, but when I first got into planted aquariums I ran around different plant shops and online sites getting my hands on as many different species of plants as I could. In the process, I kepted on adding more and more aquariums to the house. However, each tank was not for aquascaping, but instead designed to grow all the different and rare plants out there as quickly as I could.

So I packed 10 and 20 gallon aquariums with over 60-110 watts of Compact Flourescent light to send growth into overdrive. Later I even purchased expensive T5H0 fixtures to get more lighting bang for the buck so to speak. After a period, I learned and could grow almost any plant in the book. From relatively easy stem plants like Ludwigia repens and Rotala species, to more tempermental plants like Pogstemon stellatus, Rotala macranda and the occasional Tonia species.

Now, sure sending your plants to overdrive with high intense lighting will grow plants quickly, but is that what we really want when we begin to get serious about aquascaping?

Sometimes I want the answer to be yes. I don't have the patience to wait around for a month or longer for plants to fill in the aquascape. I want results and I want them now. But the problem is, many plants require and do better in different lightiing conditions. Some start growing too quickly, some plants don't grow fast enough. When you employ a lower lighting scheme you'll have less maintenance issues, trimming won't be as tedious, and best of all, you'll have an aquascape that will develop in balance. Ever try to grow a carpet of Hemianthus callitrichoides (HC) in a 60 gallon aquarium from a small 7x7 inch patch with several fast growing stem species always shooting to the surface?

Overall I think it may actually be better and follow the motto "slow and steady wins the race". You'll get a better looking and harmonous aquascape out of it.

-John N.

[Roy Deki]

I agree John, we all have to do the "high tech, high light" tank at some point in this hobby. I did and found that the plant growth was too fast. The optimum viewing of the tank was a small window. Then a major trim and it looked so ugly. Waiting it out to only have a week of "what you want my tank to look like all the time". I have discovered that a lot of "high light plants" grow well in medium light. Of course I say this with the fact that I use shallow tanks for aquascaping. This is the key for low and medium light tanks. 40 gallon breeders, 20 longs and even a panoramic 60 long are great planted tanks. You just don't need as much light as you think. I also have learned that this technique can slow down plant growth without any adverse affect on the plant. Less ferts are needed as well, not to mention trimming less. I have also notices that these tank seem to "balance" nutrient wise, much faster and easier the high light tanks. Sometimes we can make thing really hard on ourselves by thinking "Bigger, brighter the better". Like you said "slow and steady wins the race"

[George Farmer]

I'm a fan of using the minimum light possible for long-term 'scapes

With good CO2/ferts, 2 x HO T5 along the length of the tank is normally ample for the vast majority.

I've also had success with 2 x T8 @ just 1wpg. 2007 AGA Aquascaping Contest

I'm going through a bit if a mad 'scaping phase in my 80cm ATM, so high light (4 x HO T5) is used to get fast growth, so I can squeeze out as many layouts as possible in the year. The tank isn't in my main viewing area so I'm happy to see it go through the several ugly pruning transistions before it's finished.

Another aspect worth considering. Compact growth. If you want compact growth, say in HC or downoi, is high light necessary?

Cheers.

[John N.]

Originally Posted by George Farmer

Another aspect worth considering. Compact growth. If you want compact growth, say in HC or downoi, is high light necessary?

Cheers.

Though I know people who have been tremedously successful growing these plants under "medium" light conditions, both HC and downoi never really took off for me. Once I began increasing amount of light both in wattage and photo period (8 to 9 hrs) did these plants start to spread and sprout more often. In my experience, these plants require higher light to keep them growing and in a quick time frame where you dont simply give up on it. HC and Downoi remained compact in both medium and high lighting conditions.

-John N.

[John N.]

Originally Posted by Roy Deki

The optimum viewing of the tank was a small window. Then a major trim and it looked so ugly. Waiting it out to only have a week of "what you want my tank to look like all the time". I have discovered that a lot of "high light plants" grow well in medium light. Of course I say this with the fact that I use shallow tanks for aquascaping. This is the key for low and medium light tanks. 40 gallon breeders, 20 longs and even a panoramic 60 long are great planted tanks. You just don't need as much light as you think.

I've had the same experience Roy. Under high light, plants take off so quickly and really you only have about a week to enjoy the full look of the scape, before you go you're forced to do a major trim making the tank look ugly.

This is probably due to my lack of aquascaping skill, but although I do agree with you on shallower tanks reducing the need for powerful lighting fixtures, 20" high tanks don't seem have the same visual impact as a lushly planted aquascape designed with a somewhat roomy top.

-John N.

[Hoppy]

Just to be a contrarian here, I find the thing I most enjoy about a planted aquarium is watching the plants grow. So, obviously, I get more pleasure when that growth is apparent every day. When I ran my 45 gallon tank with only 74 watts I had growth, but my interest lagged because the tank seemed to look the same every day. Now, I am back to 110 watts on that tank, and I am much more pleased with the experience.

I also have a 10 gallon tank that has only 28 watts of screw in CF bulbs and no CO2. It is intended to be a low light tank. And, it bores me to death! I can look at it once a week and still hardly notice the plant growth.

The definition of "high light" isn't a clear one. I have been referring to tanks that have enough light to grow almost every plant, and need CO2 to do that, as "high light" tanks. But, you don't need much more than 2 watts per gallon to achieve that. Many people are using 3 to 5 watts per gallon - are those the "real" high light tanks?

[kakkoii]

I believe it really depends on a few things, such as plants, water chemistry, depth of the tank, watts, etc.

It is very hard to tell what a high-light tank is, so I take all the specs from the tank and see if it is high-light or not. I guess It really depends on how you look at things.

[kakkoii]

Originally Posted by Roy Deki

I agree John, we all have to do the "high tech, high light" tank at some point in this hobby. I did and found that the plant growth was too fast. The optimum viewing of the tank was a small window. Then a major trim and it looked so ugly. Waiting it out to only have a week of "what you want my tank to look like all the time". I have discovered that a lot of "high light plants" grow well in medium light. Of course I say this with the fact that I use shallow tanks for aquascaping. This is the key for low and medium light tanks. 40 gallon breeders, 20 longs and even a panoramic 60 long are great planted tanks. You just don't need as much light as you think. I also have learned that this technique can slow down plant growth without any adverse affect on the plant. Less ferts are needed as well, not to mention trimming less. I have also notices that these tank seem to "balance" nutrient wise, much faster and easier the high light tanks. Sometimes we can make thing really hard on ourselves by thinking "Bigger, brighter the better". Like you said "slow and steady wins the race"

well said, Roy! you took the words out of my mouth!

[chillaquaplants]

I also have to agree with Roy. I enjoy my 40 breeders more than any other tank I've owned. I have 4 tanks with three different light schemes (different wpg and different bulbs). The surface area is enough to plant several species and create a nice layout although a little smaller. I like the shorter height to get more light to the plants. I keep most of my colorful plants in these tanks because I can achieve the color results I want better than in my 75 gal tank. I think I've learned more in the past few months with my 40 breeders than I have through the last 2 years in this hobby.

[Orlando]

Originally Posted by George Farmer

I'm a fan of using the minimum light possible for long-term 'scapes

With good CO2/ferts, 2 x HO T5 along the length of the tank is normally ample for the vast majority.

I've also had success with 2 x T8 @ just 1wpg. 2007 AGA Aquascaping Contest

I'm going through a bit if a mad 'scaping phase in my 80cm ATM, so high light (4 x HO T5) is used to get fast growth, so I can squeeze out as many layouts as possible in the year. The tank isn't in my main viewing area so I'm happy to see it go through the several ugly pruning transistions before it's finished.

Another aspect worth considering. Compact growth. If you want compact growth, say in HC or downoi, is high light necessary?

Cheers.

I agree 100% on the least amount of light as possible.
I have less issues with algae..

[trenac]

I don't like slow growth, but I don't want fast growth either. So finding growth rate between the two extremes is what I strive for. Not only is the light choice important but also the plant choice.

The best combo I've found for myself to acheive this is a 50G with 96 watt of PC light with no stem plants. The growth rate is manageable, where pruning is not chore.

[plantbrain]

Originally Posted by John N.

Sometimes I want the answer to be yes. I don't have the patience to wait around for a month or longer for plants to fill in the aquascape. I want results and I want them now. Overall I think it may actually be better and follow the motto "slow and steady wins the race". You'll get a better looking and harmonous aquascape out of it.

-John N.

Amen!
I decided to find a way around that.
And I think ADA has as well as other folks.
You can use low light, but add a burst for 2-3 hours etc.

Similar to low light, but still gets enough high light for other species to look decent.

Requires a two or multi part light system(the trade off).
But more light is still deemed as "better" by most folks on line.

One way to get around the initial grow in phase was the Dry start method:



And 7 weeks later:


No work involved and very easy to plant.
Also, having suspended lights allows you to raise and lower the light.

This is really highly effective at reducing the light and therefore the CO2 demand, nutrient demand and the growth rates. Knowing how to grow plants well at both higher rates of growth and at lower rates is key to this approach.

That is essentially the goal and ability you seem to desire.
Grow it in fast, then slow things down..........
Light and varying the intensity is the best way to do that.
You can use the dry start method to get some of the desired plants a head start, after all, who has trouble growing a mass of fast growing stem plants vs a large rug of HC?

The focus is on the harder to fill in plants.
So you can have your cake and eat it too without much work.

After the layout grows in, you raise the light, or reduce the time, or turn off the MH's(or reduce the hours they are on etc), or turn off a few of banks of the T5's etc.

Now how do you compare such light valves amongst tanks to get comparable values that you can share data with other aquarist?

A PAR light meter.
Reef folks have been using them for decades, planted aquarist?
Maybe I am the only one?

Well, this way you can know if the HC is gettign enough light in that one corner, or at that light distance from the top of the tank, or if the light is higher than needed(excess light) for a certain species if you do not trim it more often.

After all, as plants grow, they get much closer to the light, so trimming them often keeps them in a much more stable environment.

Some grow 1-2" per day, so in 2-7 days, they can have the light intensity change by 200-500% easily. At a lower light value, perhaps 50% to 100% more light. Then CO2 and nutrients are much easier to manage.
You can go weeks without water changes also(if that's a goal), without much effort or testing, if any.

Folks talk about balance all the time, yet few bother to consider what they do is really industrial style agriculture with little organic input, high light, amplified with 10X CO2, liquid ferts and enrich sediments.

Hardly a balanced natural system.

If that's the goal(natural and balanced), then a non CO2 approach really is far more suited. But few are patient enough. In the past before Dupla promoted CO2 gas enrichment heavily, folks did not have a choice...........
even though I have magazine references from 1962 about DIY CO2........

But a non CO2 approach can be tweaked and scaped every bit as much as a CO2 enriched system. Just few try........

no water changes, allows the bacteria and critters to cycle the waste and inputs to equal the demand from the plants due to lower rates of growth from CO2 and light limitations.

Is a high light, very expensive ADA set up, with liquid ferts, enriched sediments, all sorts of who knows what being added, rich CO2 injection, 50% weekly water changes,nature or natural, balanced?

Here's a nice low light tank, not a water change for month, hardly anything added from AF(1.5 W/gal):



A few months later and benign neglect and sorely in need of a trim:



The hairgrass is maintained nicely by mowing it every so often and it stays nice a short, same with HC, Gloss, and any other weedy foreground plant.

More light = more work.
So learn to modify and use it to your advantage.
Be able to crank it up and increase dosing/CO2 etc to get ready for a contest or a photo shoot.
Do 2-3x a week 50-70% water changes.
Then garden and grow and work.

Then after you get that picture, then you back off and reduce the light, reduce the work loads etc.

Otherwise you end up having to work hard all the time, and most folks can do it for awhile, but after a few months, years, THEY GET BURNED OUT.
We all do.

This hobby and any artistic interest has it's ups and down periods.
We all are human and slack off.

Modifying our routines and choosing the best trade offs to meet our goals is the best option based on our lazy habits.


Regards,
Tom Barr

[Pat7676]

Tom great comment about this and well put. I love your tank you should start a thread over here with it.

[George Farmer]

I'm a big fan of using as little light as possible these days.

With good CO2 and other nutrients, you may be surprised how little you can use.

2 x HO T5 the length of the tank is fine for most set ups. 8 hour photoperiod. I've grown glosso, HC, red stems etc etc. In 30cm, 60cm, 80cm and 120cm set ups.

[alper]

Is it possible to express any correlation between light intensity and dissolved CO2 level? That is, how much CO2 is ideal for 4wpg (or 2wpg, 1wpg, etc.)?

[nico]

i have to agree with George as i dont think that using a huge wattage is the key to have a nice and healthy plantation , i guess that the key is to keep a good balance between ferts, CO2 and wattage , as for myself i rarely use more than 0,6W/Liter (goes down to 0,3 for my low tech tank) , still the plants growth is good (not maximum speed though) and plants are very healthy

[plantbrain]

It really depends a lot on what the aquarist goals are with light/the tank etc.

Some want fast growth for various gardening purposes, or perhaps they are more a grower, but for scaping, the slow steady and careful pruner will get much more out of the less is more concept with respect to light.

I find it really odd, and rather backwards thinking to limit nutrients to do this when light is the gas pedal when it comes to growth.

It's also really ironic that many go to nutrients so very often when not one of them have ever even bothered to test light in a meaningful manner or get really good CO2 measurements over time.

How does a plant behave as it grows towards the light?
How does this change through time or in response to frequent vs sporadic pruning?

I'll tell you a story about L pantanal............120 micro mol after initial plant, 2 days later, 200, 5 days later, 350, 7 days 550 micro moles.

That's just one week.............

HC seems fine at 25-30 micro mols at the min range.
Gloss? Even less, same for Hair grass.

High light plants?
Hardly.........

Weeds when give high light and intense growth that destroys any scape after a few weeks. Unlike CO2 or nutrients, the light can be adjusted and stabilized far more than any single parameter we have, and it controls algae when reduced better than any other parameters.

Some have the goal of having lower nutrient levels in their water column, then less light would make that or less CO2 much more manageable.

While inherently obvious, I still get folks that seem to think they should have high light.


Regards,
Tom Barr