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Follow-Up: Household CF Bulbs, Growing HC, and Non-CO2...

I wanted to follow up to this thread to share some more ideas on lighting with household CF bulbs. AirSong originally had posted asking how much light she should use to light her 2.5gal non-CO2 tank... She was interested in growing HC or other carpeting plants. To her, I answered that she would probably need more than 15 watts. I didn't want to leave it at that however. I set out to investigate and find the right answer. As such, I duplicated her setup: tank size, fixture type, water depth, distance of light from the water, etc... and then took some measurements.

The answer is that you can use anything from 14 watts to 27 watts, and beyond. It all depends on how you set it up...

I personally believe that many hobbyists underestimate the need to accurately quantify their light - especially when they are plagued by unexplained algae or dying plants. The growth in non-CO2 tanks is quite slow and getting feedback takes too long. It's good to know from the start that your lighting is in a good range, so you can eliminate it as a variable if your tank is "less than desirable".

As I discovered, these CF bulbs (14-23 watts) seem fairly tame, but how you use them can mean the difference of not having enough light, and having way too much. And believe it or not, that difference can manifest itself just by moving the light up or down a few inches.

I created a several slides to show what I'm talking about. I hope this will help illustrate how things like reflector type and distance make a big difference, and can't be overlooked - it is also the reason one person's success with a particular bulb may not be your success.

(Hopefully, you've turned off that pesky "image resize" in your user preferences - if not, make sure to unscale for readability. )


Diagram1 - Household CF Bulbs

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Diagram2 - Measuring Household CF Bulbs

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Diagram3 - 19W, 5500K Example

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Diagram4 - Does Color Temperature Matter?

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Diagram5 - 23 Watt Extremes

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Diagram6 - Reflector & Orientation

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Diagram7 - 14 Watt Example

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Cheers!
 

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Wow, very interesting! Thanks for taking the time to do this and share your findings. The question is which setup is minimally needed to grow carpeting plants like HC without c02 or in a non-c02 tank?
 

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The question is which setup is minimally needed to grow carpeting plants like HC without c02 or in a non-c02 tank?
In my non-CO2 tanks, the HC really grows thick in about 60 umols/m2/s of light (PAR) - and that's measured at the bottom of the tank where the HC is growing. So in the graphics above, any setup that shows PAR values in a range of 60-70 should be "sufficient" light. It doesn't mean you can't go higher. But in going higher, you may be over driving your soil's ability to provide enough nutrients. And even if you dose the water column, the higher light will start to give algae a good environment in which to grow.

In my non-CO2 tank with an average of 60-80 umols/m2/sec, I never change the water, I dose nitrates-phosphates-traces each twice a week, I have a soil substrate, and I don't have algae buildup anywhere in the tank.

But that wasn't always the case... During the first two months I had several patches of different kinds of algae. But I just let them run their course without attempting to fight them, and then did a removal when they seemed to be dying off. It's never come back. Also added snails and 5 amano shrimp... I was amazed at how they started to clean up the tank.

Did any of the above answer your question about the minimal setup required?
 

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...Did any of the above answer your question about the minimal setup required?
Yes, absolutley! Thanks for a very thorough explanation. I would never have guessed that 60 umols/m2/s of light would be sufficient to grow carpeting plants like HC. I would have guessed 120-220 minimum. This is good to know. When I test emersed with mineralized topsoil, I am going to go with the 60 umols/m2/s of light to grow HC or dwarf hairgrass after flooding. I did not have a par meter and even if I did, I would never had the experience of growing carpeting plants and measuring the minimal light levels needed to grow them. This helps a lot. Again, many thanks for sharing your experience and findings. And sorry for the thread hijack, but this was just so fascinating I couldn't resist.
 

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...sorry for the thread hijack, but this was just so fascinating I couldn't resist.

Friends don't let friends kill HC.

I don't think AirSong minds you hijacking.


You stated that nutrient deprivation is the biggest reason that people fail at growing HC, glosso, and riccia in non-c02 tanks.

To be clear: light AND nutrient deprivation.

I've seen that many people view low-tech, non-co2 tanks as dark, murky places that have plants with spindly growth where anubias, crypts, and java fern reign king. They are overly cautious about having extra nitrates, phosphates, and iron in the water column. And they gravitate toward plain gravel or other DIY substrates that are essentially inert and don't have good CECs (Cation Exchange Capacity).


But some are brave, and they do try to grow things like HC, hairgrass, glosso, and riccia etc. However, they apply the same low-light, nutrient thin philosophies - because that's what a low-light, non-co2 tank is... right? And when the plants eventually die off, they begin to think that such plants can only be grown with CO2 injection, high light, and heavy dosing routines.


To me, a low-light tank is this: It's a tank in which the natural, biological nutrient supply is able to keep up with the demands of the plants, and that demand is driven by the light. Nothing more, nothing less. It's a tank that relies on biology to create CO2... and these bio-chemical rates, albeit slower, are able to keep up with the plants. Surely there is a range of light intensity that works well... and how do you know what the top-end of that would be?


You can't guess this range just by making sure that you have 1-2 watts per gallon. I have disliked this rule-of-thumb ever since the first day I got into this hobby. It never made sense to me - Photosynthetic energy is what is important, not watts. I've seen people trying to grow various plants in a 20 gal tank, a gravel substrate, and a trusty bottle of Seachem Flourish; And I measured their PAR values to be around 15-25 umols/m2/s (far from 60-70 umols/m2/s). To me, it's no surprise why they are having trouble: insufficient light, and no viable nutrients (and maybe a lack of CO2 generation).


Even when they kick up the light a notch, it's not enough to fix the problem. In a non-CO2 tank, you still need CO2 and a consistent nutrient supply. To my knowledge, that CO2 comes from a robust substrate that's filled with healthy soil bacteria.


I've read so many times that you'll never see "pearling" in a low-light, non-co2 tank. This is another one of those "things" that is simply not true. The Riccia and HC in my non-CO2 tanks pearl quite a lot at the height of the day. How could this be without CO2 injection and high light? Well, it's because of a strong, healthy environment, good substrate, and sufficient photosynthetic energy. And maybe "low-light" can be higher than you previously thought... or were conditioned to think by other hobbyists.

And this is all without algae. If you really assess your lighting, and you really assess your nutrient supply, and you have a viable substrate, algae problems really become minimal.


However, IME I have seen riccia grow like a weed(even when tied to rock) in my high tech and low tech non-c02 tanks, but in the same tanks Hairgrass has died off and HC has failed to grow at all(even with ADA Aquasoil II and water column dosing). What is your explanation for this?
Well, to start, I would put Riccia in it's own class since it strictly derives its nutrients from the water column. Riccia is generally undemanding and if you're dosing the water column in both cases, I would expect it to do moderately well in both cases.

HC and Hairgrass, however, interact heavily with the substrate. My guess is that you can't just dose the water column and expect these plants to ignore the biology in their root system. Question: In the non-co2 tank, is the substrate able to generate the kind of bio-chemical activity that's needed to support the rooted plants? Sure, it's "ADA AQUASOIL:icon_excl", but how do you KNOW what it's capable of? What's it's CEC? What is the ratio between sand/silt/clay? How rich is it? What were your PAR values?

I know you don't have a PAR meter. I'm just saying that these are the things you CAN know and remove them from the "variable" list. Personally, if I really wanted to use ADA's Aquasoil, I'd pay the $50 and send it off to a lab to have it analyzed.

That's where I'd start: Determine your photosynthetic energy, and provide a substrate of known quality and content. Only then can you begin to say anything about the success or failure of a particular plant.


I have reservations about shining too intense light on a tank. Even experimenting with a 10 gallon where c02 tested ideal, water parameters were ideal, fert dosing was ideal, and even plant growth was explosive with only 30 watts fluorescent lighting(6500K daylight) that tank was literally raped by just about every algae imaginable. BGA, followed by black brush, followed by clado, and even green dust algae. The single biggest change that resulted in the algae disappearing was a reduction in light intensity from 30 watts total to 20 watts(6500K daylight)
Here again: phrases like "too intense", "only 30 watts", "30 watts total to 20 watts"... they are all ambiguous. They say nothing about actual photosynthetic energy that you are supplying. Small tanks like 10gal, 5gal, etc are tricky because it's so easy to screw up the light, either high or low. If anything, this is what I wanted to illustrate with the slides I created earlier in this thread. Overall they show how a simple change in the distance and reflector type can make huge differences in the photosynthetic energy. And if you don't know what you've got, it's setting the stage for failure (or algae, if you equate the two).

Also, another factor is the life-cycle of the tank. In my experience with using a soil substrate, all new tanks experience some form of algae as the bio-chemical processes are kickstarted after you set it up. This period can last several months. But it goes away as the plants take hold and the substrate kicks into high gear.

If you KNOW that the photosynthetic energy of your lighting is in a good range, and you KNOW that you have a robust substrate, then you can have some confidence in allowing algae to move through it's life cycle without trying to fight it.

But if you don't KNOW those things, you may be consistently supplying an environment that benefits algae and not plants. And then it will never go away. You'll be scraping and removing until the end of your days.

Just my thoughts.


Cheers!
 

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excellent data! :thumbsup:

Agreed! This should definitely be a sticky!! Mods???

Just a few questions i4x4nMore if you don't mind.

(1) You mention fine gravel as cap over the soil. Could you post pictures to give an idea of grain size of the gravel you mean. Have you ever experimented with different caps and noticed any positive or negative experiences or one working better than another. For instance, pool filter sand, Schultz Aquatic Soil, Soil Master Select, tahitian moon sand vs pea size gravel.

(2) What photoperiod do you run your lights and have you noticed any positive or negative effects on plants or algae with different photoperiods. If so, what photoperiod would you recommend.

(3) How long have your tanks been running? Have you noticed and effects of substrate nutrient depletion(via plant nutrient deifciency symptoms) and the need to add more water column ferts over time.

(4) Do you follow the 1 inch per gallon rule of stocking when it comes to fish/snails/shrimp. Do you generously stock your tanks or keep stocking to a minimum? How frequently do you feed your fish?

(5) Finally, what is your water change schedule like and how much(% of total tank water approximately) water do you change?

Thanks.
 

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(1) You mention fine gravel as cap over the soil. Could you post pictures to give an idea of grain size of the gravel you mean. Have you ever experimented with different caps and noticed any positive or negative experiences or one working better than another. For instance, pool filter sand, Schultz Aquatic Soil, Soil Master Select, tahitian moon sand vs pea size gravel.
Here's an image comparing the different gravel caps that I've used. I have not used any of the ones you mentioned. For me, as long as the gravel size is paired well with the root size, I'm not too critical about it. I have never gone below a gravel size of 1-2mm in size.


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(2) What photoperiod do you run your lights and have you noticed any positive or negative effects on plants or algae with different photoperiods. If so, what photoperiod would you recommend.
Nothing special here... 12 hours. I have not experimented with different intervals.

(3) How long have your tanks been running? Have you noticed and effects of substrate nutrient depletion(via plant nutrient deifciency symptoms) and the need to add more water column ferts over time.
Most of my tanks run for a year or more. Not that they couldn't run longer... I just want to try new things. I did experiment with running a non-co2 tank at about 100 umols/m2/sec of light and it did great for about 10 months without algae - then, all of the sudden at the 10 month mark, it totally went south. All the plants turned pale and algae became dominant. I attributed it to the soil finally giving out - but can't say for sure.

With my current non-co2 tanks with soil substrates, I have been dosing using EI. I dose it the same way as I do my CO2 tanks, just less frequent. It's too early for me to tell how this will extend the life of the soil.

(4) Do you follow the 1 inch per gallon rule of stocking when it comes to fish/snails/shrimp. Do you generously stock your tanks or keep stocking to a minimum? How frequently do you feed your fish?
I keep stocking to a minimum. In general, I prefer relatively few fish, with heavy plants. I feed them only once a day, and sometimes skip a day. I only feed them live or frozen foods. No flake foods.


(5) Finally, what is your water change schedule like and how much(% of total tank water approximately) water do you change?
In my non-co2 tanks, I never change the water. Periodically, I check the nitrate and phosphate levels to modify my EI dosing routine.

On the CO2 tanks I change 50-70% of the water every 1-2 weeks.



Cheers!
 

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thanks Jeremy for the very informative reply. i also think it should be made a sticky.

one final request, if i may. could you provide lighting data for the three tanks. that is, how are your bulbs oriented/kind of reflector, types of bulbs, wattage, k, distance from light to bottom of tank, size of tank. i think it would be instructive to look at. thanks.
 

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milesm said:
one final request, if i may. could you provide lighting data for the three tanks. that is, how are your bulbs oriented/kind of reflector, types of bulbs, wattage, k, distance from light to bottom of tank, size of tank. i think it would be instructive to look at. thanks.
Yes, I can do this once I'm back in town... currently traveling.


wow, this truly gives a whole new meaning to a non co2 injected tank, So I have to ask, were all three tank pics non co2? Amazing..
I was wondering when someone was going to ask that... The top and bottom tank were run as non-co2, the middle tank was co2 injected (as is evident from the drop checker hanging on the side of the tank <wink>).

The bottom tank has a CO2 system, but I only used it in the beginning of that particular setup. I found that it was growing way too fast. I couldn't keep up with the plant trimming. So, I slowed the growth rate down... Since it has a soil substrate, I stopped the co2 and reduced the light from 120 umols/m2/s down to 60 umols/m2/s using a photographic neutral density filter on a piece of glass directly below the lights. That's another way you can control your lighting if removing a bulb is not an option or if you can't change the distance.


The reason I showed all three tanks together was that I wanted to illustrate that a non-co2 tank doesn't have to be the ubiquitous anubias/crypt/javafern style tank. I prefer brighter, sparkling tanks with verdant growth ;-)

My successes are modest, and I'm not claiming to be a master of this. But I hope to attract others with the same mind set and share our experiences and methods.


Cheers!
 

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Hey Jeremy,

Any way we could get shots of the reflectors used in your tests? ie: The one for the vertically mounted bulb and the horizontally mounted bulb. :)

Thanks.
 

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I think this is one of the most helpful posts I've read on here. I read it before lights on on my 2.5g tank, that's had somewhat of a halt on the HC growth, and the leaves were starting to get a little pale. I raised the light 1.5" before lights on and it looks nice and green like it should again! :D
 

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That is some really great PAR data for power saver bulbs. I plotted the data on log log paper to see what kind of relationships are there. It looks like the light intensity drops a little faster than if it were just an inverse square drop off. I'm not at all sure why that would be. Also the relationship between intensity and bulb wattage isn't quite linear, with the intensity increasing a bit faster with power than if it were linear. That is understandable because there is more area radiating light with the higher wattage bulbs and less dark area of tube. Also, at equal distances between the light and the sensor, the vertical mounted bulb gives about 55% more intensity than the horizontal mounted bulb. That is probably from less restrike.

The data also has a lot of practical use for guesstimating how many of what wattage bulbs will give a 100 micromol (for example) intensity at the substrate for any given tank size.

Thank you very much for doing this.
 

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I really enjoyed those illustrations too. Made it easily understood to a non techy person.
Cool, I'm glad. That's what I was aiming for. Was quite fun to do. If we all talked in terms of PAR instead of watts, it would eliminate a lot of variables in diagnosing setups. I do wish the meters themselves were cheaper, I know that is the main barrier for hobbyists.

That is some really great PAR data for power saver bulbs.
I also was a little surprised at how useful they could be.

I plotted the data on log log paper to see what kind of relationships are there. It looks like the light intensity drops a little faster than if it were just an inverse square drop off. I'm not at all sure why that would be.
Raising or lowering the reflector over a small tank like that is going to change the light distribution and also reflect off the side glass differently. That divergence from the inverse square relationship basically indicates how the reflector shape and material comes into play. Additionally, the water itself absorbs the light in addition to the inverse square law, no?

Also the relationship between intensity and bulb wattage isn't quite linear, with the intensity increasing a bit faster with power than if it were linear. That is understandable because there is more area radiating light with the higher wattage bulbs and less dark area of tube. Also, at equal distances between the light and the sensor, the vertical mounted bulb gives about 55% more intensity than the horizontal mounted bulb. That is probably from less restrike.
I also think that restrike is a huge factor in limiting the radiating light in the horizontal configuration. But that's what is great about using the PAR meter... if you reconfigure your lighting, you can see in realtime what the effect is going to be in terms of photosynthetic energy for the plants. That 55% increase is not very noticeable to the naked eye, yet it is there.

The data also has a lot of practical use for guesstimating how many of what wattage bulbs will give a 100 micromol (for example) intensity at the substrate for any given tank size.
Yes, a virtual PAR meter of sorts. The thought had crossed my mind... but without accounting for reflector types, light distribution variations, water depth, turbidity, and brand of bulb, you're still back to not knowing exactly how my photosynthetic energy you really have.

Thank you very much for doing this.
You bet.

Any way we could get shots of the reflectors used in your tests? ie: The one for the vertically mounted bulb and the horizontally mounted bulb.
Sure, however, there's not much left to the imagination concerning those two fixtures shown in the diagrams. The metal dish reflector is the exact same material on the inside. The desk lamp is simply painted white on the inside. However, I can photograph the interiors when I get back in town.

I think this is one of the most helpful posts I've read on here. I read it before lights on on my 2.5g tank, that's had somewhat of a halt on the HC growth, and the leaves were starting to get a little pale. I raised the light 1.5" before lights on and it looks nice and green like it should again!
I have no doubt that raising your lights caused a visual difference to you, but the real question is "what was your photosynthetic energy before you raised the fixture, and what was it after?" Such a change in the lighting would take a bit of time to see the results in terms of the growth of your plants - especially with non-co2 - probably on the order of weeks. By raising the light a couple of inches, you are effectively reducing the photosynthetic energy being supplied to the plants... that will, in turn, reduce the demand for nutrients. If there is less demand for nutrients, then your substrate may have a better chance at providing them through normal bio-chemical reactions.

By using this PAR meter, the idea here is to remove the notion of "how much light/watts do I need?" Instead, we focus on how much photosynthetic energy (PAR) is being supplied to the plants. This is not something you can determine just by looking at the setup, or knowing how many watts you have. Maybe you were overdriving the bio-chemical system in your tank, maybe not. A PAR reading would give us a better answer.

If you were already in a good range, then maybe your paling HC is because of a lack of nutrients overall. Do you see how this conversation would be a lot different if you said "I am providing X amount of photosynthetic energy to my plants, but the HC hasn't been doing well." ? Then we could immediately know if your lighting was at fault or not, and then move on to other factors.


yeah I must of not seen that drop checker..lol..I was so focused on checking out those foreground plants...lol, will the tanks by be small...I still love the meaning behind them, it's nice to know something like that is possible
Yes, I understand, totally :)


Cheers all!
 
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