[niko]

Did some more digging on T5HO vs. LED. Unless you have a huge LED rig the T5HO still seem to stay ahead.

Here's a video. Don't know how deep the tank is. But if the light fixture is 25 inches long (bulb length 24" + say 1" for end caps) you can judge the depth. I estimate that the water is about 15" deep. Note the PAR at the bottom. At 1:07-1:10 it's about 90. That's with 2x24W bulbs AND not right under the bulbs.

Note that getting close to the front glass actually increased the PAR a little. Also note how fast the PAR on the bottom decreases when he moves the sensor somewhat close to tall stem plants (not even right under them).

So how come carpet plants that grow well in a tank and receive vastly different PAR do grow like an even carpet? How come you don't see areas that look great and areas that look just ok? I have seen an extreme example of that - a tank which had fresh green leaves growing in complete darknes (Java Fern, the back bottom side of the tank was in complete darkness because the thickly growing plant blocked all the light). To this day I cannot really buy the explanation that plants transport and shuffle nutrients and adjust the metabolism so the entire plant gets to live a life full of beauty and joy. Why on Earth leaves growing in complete darkness will be as green as the ones reaching the surface 3" below the light? Bottom line generalization is that when plants grow well they indeed do things that make no sense IF we just look at numbers and look at things from our limited perspective.

 

[niko]

And since we discuss just numbers here it would be good if we note once again that numbers are not everything.

Here's an example from today:
Remember the tank with the 220W VHO bulbs that produced ridiculously low PAR of 45? The one that I installed brand new killer T5HO rig. Using 1x54W Giesmann Midday bulb and 1x54W Giesemann AquaFlora bulb (total of 128W). But the bulbs have brand new Tek reflectors and are driven by a Fulham Workhorse ballast. You cannot stand by the light fixture and have your face illuminated from the side - the light blinds you.

So that is the light I installed on that tank the other day. The color is beautiful. However what I found floating in the water is against everything I believe. N=30 and P=2.5. Thanks to the "fertilizers in the water must be the solution" mentality I now have a tank with super high light, and a nuclear explosion waiting to happen. Guess where I'm headed today with 2 big pails of clean water?

But why is all that interesting? Because IF we look at the numbers only (high PAR, N, and P) we see a disaster coming. I want to hear from the people that will tell me today that the tank will be just fine and I don't need to worry about it. We all know what will happen in the next few days in that tank. But we will all agree that if the tank had been gradually brought to that same state it will probably be bursting at the seams with extremely healthy plant growth. Without any algae. The point is that if we just focus on numbers we WILL BE way off. I say that because it is the rule to see questions and advice about reaching and maintaining certain values (ppm fert concentration, bps of CO2, wpg of light, gph of flow).

And here's a common sense refresher: From what I see now with that PAR meter very much ANY bulb will provide enough PAR to grow any plant you want IF the tank is shallow. 8 to 10" tank and you can use the oldest bulb you can find at a garage sale at a 100 year old estate sale or something. It will still grow plants. Get you a deeper tank - say 20 inches and it looks like you run at the same issue again and again - good PAR is hard to get to the bottom. So the question is - Do you need a super efficient light with super high PAR if you can run the tank in a certain way and lead it to a state in which it works despite what the numbers tell you is way off?

 

[Yo-han]

Note that getting close to the front glass actually increased the PAR a little. Also note how fast the PAR on the bottom decreases when he moves the sensor somewhat close to tall stem plants (not even right under them).

I found the same thing. Guess it is from reflection of the glass.

So how come carpet plants that grow well in a tank and receive vastly different PAR do grow like an even carpet? How come you don't see areas that look great and areas that look just ok? I have seen an extreme example of that - a tank which had fresh green leaves growing in complete darknes (Java Fern, the back bottom side of the tank was in complete darkness because the thickly growing plant blocked all the light). To this day I cannot really buy the explanation that plants transport and shuffle nutrients and adjust the metabolism so the entire plant gets to live a life full of beauty and joy. Why on Earth leaves growing in complete darkness will be as green as the ones reaching the surface 3" below the light? Bottom line generalization is that when plants grow well they indeed do things that make no sense IF we just look at numbers and look at things from our limited perspective.

Asked the same question a few days back. My glosso is growing perfectly healthy substrate hugging in the front. But it sends runners below my wood and crypts and it is still hugging the substrate. I planted a few new pieces of glosso in the dark, not in connection with leaves in the light and will see whether this will grow upwards... (it did before but maybe something changed)

 

[niko]

Talking about plant leaves looking good in darkness or shaded areas... Some years ago a legendary American aquarist visited Amano's house and walked all over the big tank. He said that at that time there were Rotala stems in the back of the tank. Tank is what? 5 feet tall? He said that the rotalas were about 4 feet long if I'm not mistaken. Ok, good, amazing allright, whatever. But what he saw was that every single leaf on these stems was perfect - starting from the leaves by the AquaSoil. Try that at home if you can.

 

[dbot]

Aquarium size: 3.5 Gallon - 34.5 cm x 20 cm x 23 cm (L x W x H)
Type of light fixture AND reflector: Finnex FugeRay: Ultra Slim LED + Moonlights 12"
Number of lamps, bulbs, or tubes, and wattage: 1 lamp, 3*16 LED
Age of lamps, bulbs, or tubes: 1.5 years
Other information: 7000K bulbs + moonlights
Distance from light fixture to surface: 2"
Distance from light fixture to substrate: 8.5”
PAR VALUES MEASURED AT UNDER WATER SURFACE: 100
PAR VALUES MEASURED AT SUBSTRATE: ~50 +/- 5

Aquarium size: 2 gallons - 18.4 cm x 22.9 cm x 25.4 cm (L X W X H)
Type of light fixture AND reflector: Finnex Energy Saving Epoch Cliplight + Moonlights
Number of lamps, bulbs, or tubes, and wattage: 1 lamp, 26W, 1 bulb, 3 tubes
Age of lamps, bulbs, or tubes: 6 months
Other information: 30,000k - 10,000k, 3U Type, Energy Saving Blue/White bulb, 2 LED Spot Moonlight
Distance from light fixture to surface: 10.2 cm
Distance from light fixture to substrate 26 cm
PAR VALUES MEASURED AT UNDER WATER SURFACE: 75 +/- 5
PAR VALUES MEASURED AT SUBSTRATE: 20 +/- 5

Aquarium size: 2 gallons - 18.4 cm x 22.9 cm x 25.4 cm (L X W X H)
Type of light fixture AND reflector: Fluval LED
Number of lamps, bulbs, or tubes, and wattage: 1 lamp, 31 LED
Age of lamps, bulbs, or tubes: 7 months
Other information:
Distance from light fixture to surface: 8.3 cm
Distance from light fixture to substrate 23.5 cm
PAR VALUES MEASURED AT UNDER WATER SURFACE: 40 +/- 4
PAR VALUES MEASURED AT SUBSTRATE: 5 +/- 2

I have one last tank to test it on but I haven't filled the tank...need to drill some holes...

 

[niko]

I played with two kinds of bulbs - a 100W halogen bulb and a 100W Mercury Vapor bulb. Measured PAR with a meter that doesn't belong to the club.

Readings for the 100W halogen where mind blowing:
250 PAR at 3-1/2 ft. (air only)
110 PAR at 4 ft (through 14" of water)
Super high PAR. No LED or Fluorescents come even close.
Shocking shimmer when the bulb is 3 ft. above the tank.
Rated for 4200 hours only. Runs hot but not hotter than a powerful LED.
Color of the light was beautiful - very natural.

Readings for the 100W Mercury Vapor where mind blowing too:
Barely PAR 20 at 3 ft. through air. But you could not look at the bulb, it is so bright.
Apparently quite a bit of the light these bulbs produce is in the UV spectrum or something like that.
There are no ballasts being sold for these bulbs any more. Bulbs yes, ballasts - no. Either way - super bright with a super low PAR.

 

[Michael]

We are still trying to define "high light" and "low light" in terms of PAR measurements. Here is an interesting tip from George Farmer that originally appeared in an article in Practical Fishkeeping http://www.practicalfishkeeping.co.uk/content.php?sid=5633:

"As a tip, buy or borrow a PAR meter to measure your current lighting levels. If it's over 50 µmol at the substrate you'll need CO2 injection and regular fertiliser additions. If you have suspended lighting raise or lower the unit to adjust the intensity. Lighting over 100 µmol at the substrate will demand high CO2 and nutrient levels and is only recommended for experienced plant growers."

This advice gives us a possible criterion for the CO2/no CO2 decision.

 

[niko]

"As a tip, buy or borrow a PAR meter to measure your current lighting levels. If it’s over 50 µmol at the substrate you’ll need CO2 injection and regular fertiliser additions. If you have suspended lighting raise or lower the unit to adjust the intensity. Lighting over 100 µmol at the substrate will demand high CO2 and nutrient levels and is only recommended for experienced plant growers."

That advice should also make you ask yourself 3 more questions:
1. "Can the substrate help in any way in feeding my plants?"
2. "Do I want a tank that is stable and low maintenance or not?"
3. "Is more always better?"

 

[BriDroid]

I'm not using glass tops and I'm using a Toms surface skimmer to keep the surface clean.

PAR DATA COLLECTION
March 31, 2013

Aquarium size: 72 bow front
48"L 12"W on the ends 18"W at the middle and 24"D

Type of light fixture AND reflector: Finnex Ray 2 DS 48" 7000K LEDs

Number of lamps, bulbs, or tubes, and wattage: 384 LEDs, 39 watts

Age of lamps, bulbs, or tubes: about 4 months old

Other information:

Distance from light fixture to substrate: 22"

PAR VALUES MEASURED AT SUBSTRATE: Directly under fixture, 43 par
6" off from center, 33 par

Comments:
Directly under light
At surface, about 1.5" under light 630 par
6" 200 par
12" 100 par
18" 68 par
22" at substrate 43 par

6" out from the center of the light
At surface 35 par
6" 73 par
12" 77 par
18" 47 par
22" at substrate 33 par

I'm now running this light over my 33 long. I'm getting about 100 PAR at the substrate. I think I'm going to raise it up a few inches just to get myself into the 80's.

 

[Michael]

Of all the ready-made LED fixtures, the Finnex ones seem to be consistently useful for planted tanks.

 

[Zapins]

Out of curiosity what is the PAR value at noon on a sunny day?

 

[Michael]

See post number 8. Noon in June in Dallas: 1,700 umols.

 

[Zapins]

Wow, and what would you consider high light for aquatic plants? I know there seems to be some debate on this topic, but roughly?

 

[BriDroid]

How accurate is that 1700 Michael? The Apogee sensors are calibrated for either natural sunlight or electric light from the factory. I'm assuming the clubs meter is for electric light? If so, I wonder how far off it would read under natural light?

 

[Michael]

Zapins, that is what we are all trying to figure out! Here's my subjective opinion, and I am inviting scorn from all corners with this. But I can take it, LOL! All numbers refer to PAR at substrate.

20 umols is low, below this only the most shade tolerant plants will grow well. 40 umols is medium--a very large variety of plants will grow well. 80 umols is high and will grow almost anything. Much above 80 umols at the substrate you are driving the Ferrari on an icy mountain road, and had better know what you are doing.

Something I think is important is photoperiod, and how long the light is at what intensity. Again, my subjective opinion is that the "midday burst" schedule most closely resembles nature, and you may be able to flirt with high PAR using that method. This comes partly from my observations of sunlight in my own ponds. Except at midday, surface reflection greatly reduces the amount of light received by submerged plants.

BriDroid, our meter has both electric light and sunlight settings. The outdoor readings were taken with the meter in sunlight mode. However, the manual says that if you use the wrong setting the error is only 5-10%, I can't remember up or down. You can get that much change just by moving the sensor a fraction of an inch in a planted tank, so I regard it as insignificant.

 

[Zapins]

Interesting. Those values fall roughly into the same value difference I see between hydroponics values and aquatic plant values. It seems like aquatic plants need between 10-20x (closer to 10x) less nutrients than hydroponically grown plants. So it doesn't surprise me that from 1700 to 80 PAR makes sense, that is roughly 20x less light, which is inline with 10-20x less nutrient requirements. Obviously light drives the entire process, so if you need 20x less light you should need roughly 20x less nutrients on average.

 

[niko]

Michael is right - PAR of 50 is all you need. Everything above that puts you in a situation where you need to raise the CO2 and run all day after nutrients. Most people will say that works but it really does not because there are interactions between the basic fertilizers that happen when the CO2 is to high. These interactions are not what we normally discuss (like P and Fe for example). Basically you can be starving the plants from ferts that you assume you have enough of because you add a lot of them (K is one example).

Once again ADA seems to have figured all of that out more than a decade ago - pH=6.8 and medium light. Providing most of the nutrients through the substrate can be seen as a stable way to provide them. If you rely on ferts floating free in the water who knows what happens when you over or underdo this or that other factor. That's where we have been swimming for the last decade.

High PAR can be provided in many ways but you better understand what happens if you actually provide it. It looks like the experiment that the club started 3 or so years ago have given numbers that start to make more sense now. Another experiment that I hope will materialize is finding what is a "proper" COD (organics loosely put). JeffyFunk is trying to find that out. Once again - ADA has had their eye on that too and even sells a seemingly toylike test kit for it. I am glad that we are talking about all these things, despite the funny time stretch from the "Amano Revolution" in the late 90's until now.

 

[Zapins]

While Amanos setups do seem to match some of the ideal values we are discovering I am not convinced they knew about these values first and then designed their products to match. I think they just happened upon a formula that seemed to work and stuck with it.

 

[niko]

Checked the PAR of two common bulbs - a parabolic one used to light up the driveway and a kind of bulb that is meant to be used instead of an incandescent but it has a halogen setup inside. The PARs where pretty much mind blowing:

Driveway bulb: PAR120 at 3 feet.
The driveway parabolic is 100W.

Halogen "incandescent": PAR100 at 1 foot (and that is without any reflectors, just a bare bulb shining in all directions. With a reflector the PAR will be spectacular for sure).
The halogen "incandescent" is 72 watts. /u

Everybody will say that both bulbs run too hot. But try to get the same PAR from the same distance using LEDs - you will have to have serious cooling. T5HO on the other hand are tubes - they will run cooler but you cannot focus the light over a smaller tank for example. And don't forget that with the parabolic driveway bulb you can make shimmer. Same for the "incandescent" if you use a tight round reflector.

Both bulbs can be found in any hardware store. Very cheap ($3 and $10) and can be screwed in any incandescent bulb socket. I do think that both of them bend the rule "You can't have cheap AND great". The bulbs are the the rock bottom cheapest light setup one can get. And the performance kills both LEDs and T5HOs because there are no special ballast, drivers, etc.

The color of the light from both bulbs is about 5500K - not reddish at all but not stark white.

 

[Michael]

Is the driveway bulb a halogen also? I see a trip the hardware store in my near future!