Low tech lighting levels

[Ady34]

I stand corrected, the article does indicate a greater plant mass increase due to light over co2. A marked increase is then noted from the addition of both high light and high co2.
I think I'll have a proper read of the article again!
Its too late now though 🙂

 

[Guest]

It's not particularly well written in places and can be a bit confusing😕 ...I guess something has been lost in translation to English🙄 ...

 

[dw1305]

Hi all,
As some will know I'm not an "added CO2" user, but I think an important factor in all of this is that elevated CO2 levels will actually reduce the LCP. Sorry it is a bit of strange link, but it is quite useful: <Teachers' Guide - Plants And Light - Tomatosphere>.

It was because of the CO2 factor that I used a floater for the "Duckweed Index". Because the leaves have access to atmospheric CO2 (at 400ppm) it removes CO2 from the equation. This allows us to just look at the relationship between PAR, nutrients and growth.

I've some-how managed to post the same link twice in my previous post, but the other old thread I meant to link to was this one (from 2010): <Light Compensation Point and optimal PAR levels | UK Aquatic Plant Society>, and particularly this post.

I recently bought a new light (2nd hand via UKAPS) which doubled the light output and one very noticeable effect has been I have a lot more biomass in the aquarium, in this case light availability was limiting plant growth (although I practice nutrient depletion and would have said that plant growth was nutrient limited before the addition of the light).

I can't measure the PAR at the bottom of the tank, but I'd be reasonably confident that I'm now maintaining light levels at the tank bottom (by an occasional thin through of the floating plants and upper canopy stems/leaves) at pretty much the same level as it was before the new light, the only difference is that there is now more energy in the system and this has allowed a thicker canopy to grow.

cheers Darrel

 

[Graham1984]

So, it theory, If i went with a 2lt diy co2 set up with my low light, but circulated the water a bit more, my results will be better, Not show stopping but better.
I know I cant provide anything near enough co2 to grow thick low growing carpets, but at the same time thats not what wanting to do anyway.

for me the idea behind the low tech approach was to maybe to try to avoid getting bogged down in the science bit. Ive been down the high tech/energy path before
and found it to involved for the time/money I have available to me. (im sure others are in the same boat.)

with the t8s, I have 0.9wpg, and with t5sho, I have 1.6wpg and the higher intensity, I know PAR is the better way to asses light these days, but I dont have the equipment to do that.

from what I understand, water from the tap will contain co2, my soil sub will produce some co2, and if I have a diy set up that is well circulated with causing too much surface movement, In "old money" both levels are fairly low, so I should get some sort of growth out of what I have, I dont mind doing a bit more water work to keep things looking good, if providing some co2 and a bit more light will give me better results. (all be it not at the optimal levels)

 

[Ady34]

It's not particularly well written in places and can be a bit confusing😕 ...I guess something has been lost in translation to English🙄 ...

To be honest I think I completely misread it 🙂
The article seems to contradict somewhat the current train of thought regards light and co2, however I'm guessing tests on individual species would be more telling and perhaps more complete an assessment. I will re read it but perhaps more information on the tests would be helpful. Riccia is a floater by nature so perhaps that has something do do with it? Perhaps a new topic of discussion based on that article would be good.

 

[Guest]

Hi all,
elevated CO2 levels will actually reduce the LCP.

And vise-versa...elevated light levels will reduce the CO2 compensation point... from the same paper - 'With more light available, less investment in the light utilisation system is necessary and the free energy can be invested into a more efficient CO2 uptake system so that the CO2, which is present in the water, can be more efficiently extracted.'

At the end of the day all we are trying to do is reduce our plants need to adapt to resource limitation. Adaptation to resource limitation can be very expensive reducing the energy available for growth.

 

[Guest]

To be honest I think I completely misread it 🙂
The article seems to contradict somewhat the current train of thought regards light and co2, however I'm guessing tests on individual species would be more telling and perhaps more complete an assessment. I will re read it but perhaps more information on the tests would be helpful. Riccia is a floater by nature so perhaps that has something do do with it? Perhaps a new topic of discussion based on that article would be good.

Maybe the current train of thought is wrong...or alternatively - like a lot of planted tank paradigms - it's just been misinterpreted and/or misunderstood. I think that forums like ours sometimes get caught in a bit of a bubble and we tend to create our own paradigms that become entrenched beliefs even though they were originally based on nothing more than aquarium folklore. The problem then is that it's often difficult to accept an alternative, or more accurate, hypothesis even though supporting scientific evidence is staring us in the face; it's often considered heresy. It's nothing new the Catholic Church have been resisting paradigm shifts that question their dogma for centuries...hence the various inquisitions...DAHHH...NO ONE EXPECTS THE SPANISH INQUISITION!!!...😱

 

[dw1305]

Hi all,

for me the idea behind the low tech approach was to maybe to try to avoid getting bogged down in the science bit. Ive been down the high tech/energy path before

I think your right, personally I stick any available light over the tanks (most of my tanks and lights are "pre-owned" or DIY), use whatever substrate I have to hand, plant heavily, maintain a large plant mass and then feed (if necessary) via the "Duckweed Index" <Low maintainence, long term sustrate | UK Aquatic Plant Society>. It is a KISS solution.

If I wanted to go even lower maintenance I'd go for a wide shallow tank with a large surface area to volume ratio, the advantage of this is that a larger gas exchange surface means quicker diffusion of CO2 and oxygen both in and out. I think tank architecture is part of the reason why "BigTom's" "Bucket of Mud" has been so successful, and if you read through his journal <Tom's Bucket O' Mud - new vid page 28 | UK Aquatic Plant Society> you can see it is an absolute triumph.

At the end of the day all we are trying to do is reduce our plants need to adapt to resource limitation. Adaptation to resource limitation can be very expensive reducing the energy available for growth.

This is true, but I think resource limitation can be a useful tool. I'm not aiming for optimal plant growth, quite the opposite, I'm aiming for a low level of sustainable growth. This might seem a strange aim, but there is a reason for it.

I want plant growth to be limited by the availability of nutrients, my principle aim is to have the plants mop up as much of the available nitrogen as possible. Plant - microbe biological filtration is extremely efficient, which allows it to deal with large bio-loads in sewage treatment systems etc., but it also means that you can use them to maintain very high water quality.

cheers Darrel

 

[Ady34]

There's always more to anything that meets the eye, but I'm for sure not going back to more light is best! The problem is all things are relative and whilst light can yield better results in that particular test, in our home tanks many fail due to over lighting and under feeding, hence why co2 is such a hot topic. People have felt the need to use very high lighting in an attempt to succeed and have ended in failure due to not paying attention to other important factors like co2 and distribution which is proved along with light to yield the best overall results. The ideal scenario is to have unlimited everything 🙂 limiting light is safest due to the implications of over lighting. matching co2 and lighting is much better than limiting one or the other, more often than not it is the co2 that is limiting and not the light as that's easy to plug in over the tank. Co2 is much more tricky to get right. I think what is clear is that if you want to grow fast then co2 is as important as the light.

So, it theory, If i went with a 2lt diy co2 set up with my low light, but circulated the water a bit more, my results will be better, Not show stopping but better.
I know I cant provide anything near enough co2 to grow thick low growing carpets, but at the same time thats not what wanting to do anyway.

for me the idea behind the low tech approach was to maybe to try to avoid getting bogged down in the science bit. Ive been down the high tech/energy path before
and found it to involved for the time/money I have available to me. (im sure others are in the same boat.)

with the t8s, I have 0.9wpg, and with t5sho, I have 1.6wpg and the higher intensity, I know PAR is the better way to asses light these days, but I dont have the equipment to do that.

from what I understand, water from the tap will contain co2, my soil sub will produce some co2, and if I have a diy set up that is well circulated with causing too much surface movement, In "old money" both levels are fairly low, so I should get some sort of growth out of what I have, I dont mind doing a bit more water work to keep things looking good, if providing some co2 and a bit more light will give me better results. (all be it not at the optimal levels)

Hi,
If your trying to avoid being bogged down in the science I'd say stick to the t8 lighting and go low tech. Don't even think about co2. If you have good success with the t8s and want to try for more growth add higher light and see what happens, if the plants react badly then you'll know you need to either reduce light intensity again or provide additional food.
Cheerio
Ady

 

[dw1305]

Hi all,

water from the tap will contain co2, my soil sub will produce some co2, and if I have a diy set up that is well circulated with causing too much surface movement, In "old money" both levels are fairly low, so I should get some sort of growth out of what I have, I dont mind doing a bit more water work to keep things looking good, if providing some co2 and a bit more light will give me better results.

Should also have covered this. You can ignore the CO2 from the tap, it will equilibriate with atmospheric CO2 levels pretty quickly once the water isn't under pressure. The production of CO2 from the substrate and bio-load respiration may be quite high, but levels will build up mainly at night and this means that you run the risk of asphyxiating your fish before the lights come on.

So, it theory, If i went with a 2lt diy co2 set up with my low light, but circulated the water a bit more, my results will be better, Not show stopping but better. I know I cant provide anything near enough co2 to grow thick low growing carpets, but at the same time thats not what wanting to do anyway.

More flow is very relevant, mainly because it increases the gas exchange surface, if you are adding CO2, it means it will be lost more quickly, but if you aren't adding CO2, as the gas exchange surface becomes larger the levels of CO2 in the water and atmosphere will reach equilibrium more quickly. In most situations this is a "win win" situation as both dissolved oxygen and CO2 are constantly replenished.

cheers Darrel

 

[roadmaster]

Well, not entirely as the article shows that co2 grows more plant mass, light dictates the speed at which they try to grow. Small foreground plants need more light to grow faster to fill in the space faster, we are impatient in the most part so it is desirable to have high light to speed up the process and get a 'carpet'.....however without matching the co2 to the light we end up in trouble. In your instance without co2 addition the plant will require less light to succeed but will grow at a much slower rate.
It is safer (plant health wise) to add more co2 and less light as that way you run into fewer issues either algae or melt.

I think folk's are impatient period..

 

[Guest]

There's always more to anything that meets the eye, but I'm for sure not going back to more light is best! The problem is all things are relative and whilst light can yield better results in that particular test, in our home tanks many fail due to over lighting and under feeding, hence why co2 is such a hot topic. People have felt the need to use very high lighting in an attempt to succeed and have ended in failure due to not paying attention to other important factors like co2 and distribution which is proved along with light to yield the best overall results. The ideal scenario is to have unlimited everything 🙂 limiting light is safest due to the implications of over lighting. matching co2 and lighting is much better than limiting one or the other, more often than not it is the co2 that is limiting and not the light as that's easy to plug in over the tank. Co2 is much more tricky to get right. I think what is clear is that if you want to grow fast then co2 is as important as the light.

I'm sure you're right, and the main gist of the Tropica paper supports your view...really all it's saying is what we already know - light is of key importance to plant growth and health but you can have too much of a good thing...

I think that perhaps where we maybe going wrong is to assume that CO2 is a panacea at the expense of providing adequate lighting...all parameters have role to play - especially light - and we need to balance them according to our goals, whether it's a supercharged injected tank or whether you want plant growth to be limited by nutrient availability like Darrel.

 

[roadmaster]

I was called away from my computer before I could finfish my thought's.
I think if low tech,or low energy,low maint,is ones goal then they should choose that method and someones advice and follow it.
I chose Tom Barr's NON CO2 method and have no complaint's.
I also enjoyed Troi's tutorial on soil based tank's, particularly the CO2 he mentioned that can be generated from the soil.(So I added soil base).
This along with CO2 as by-product of fish respiration,is what it is in my tank's.I add dry fertizer's as per Tom's method and that leaves only the lighting to worry bout or adjust. Ten hour's of my present lighting bring's hair algae, Seven hour's is all I can use at present.
Plant's grow slowly and it took two year's for growth seen in my avatar.
Hardest part for me,,was waiting for the puny sprig's I purchased to fill out in 300 litre tank but it gave me more time to study/learn from folk's here.
I think many folk's grow tired of the waiting,but now,,when I need to place plant's in another tank or move plant's about to create new look,,I have mature specimen's to quickly fill in where i need them.No waiting for mature plant's to reach good size,,no melting from transistion from emmersed to submerged..and no constant battles with algae from desire to flood the tank with more light than the low energy method can tolerate.
I very much like the discussion's in these type thread's and have learned a great deal.
Am never as amazed by that which I don't know,,as I am by that which I thought I did know.😀

 

[Ady34]

Agreed Troi.
Trouble is always that both co2 and light are lowest at the substrate level. To get higher levels of light down there then the upper regions will automatically be exposed to 'megawatt' proportions of par. In that respect increasing distribution of co2 to get it down there may be better for the overall health of the tank being as co2 can reduce lcp? Just a thought....

 

[Guest]

And it's a thought that makes perfect sense...and is in total accordance with my previous comment...it's still all just about balancing the right light levels with other parameters - CO2 or otherwise.

 

[bridgey_c]

Im new to this game with about one years experience of co2 injection. I might be wrong then but thinking more about Troi's points, I think it was such a hurdle in the past to convince people that more light, 99% of the time is not better, that it took a sledgehammer to smash the nut, so to speak. When the beginner walks into a fish store and walks out with a tank with T5 lighting they will not have too little light. I guess then that in 99% of the problems, too little light is not the answer. Getting people away from thinking they need more light was such a tough sell in the past that the mere thought of it ever being advised again probably sends shivers down the backs of the 'heretics' who first proclaimed it.