Persistent old leaf problems.

[clonitza]

I don't think you'll get accurate results without a PAR meter or without someone having the same lamp telling you the PAR readings. Anyway I think with a single lamp without reflector you'll be in the 50-75 range which is really fine for any plant. You can also try and hang your luminaire and raise it 30-40cm more.

Algae issues won't go away very soon but with a little bit of patience, tweaking your flow and CO2 distribution you'll get your tank stable.

Mike

 

[ceg4048]

Golly, it would never occur to me to imply that some are anointed with supernatural plant growing powers while others are simply hapless bozos intent on self destruction. I do apologize if that's how it was interpreted. We all start any hobby by having limited knowledge, and our success depends on how much we learn and how we are able to implement the principles that we learn. Undeniably, there is some degree of luck as well as some innate ability involved as well, but as you quite rightly mention, it is the application of the principles that has the greatest impact. Hobbyists suffered algal blooms for many years thinking that nutrients in the water column were the root cause, until it was discovered that the truth was actually just the opposite. Many who continue to fear nutrients and who try to eradicate them from the water often meet with failure, while those who learn that nutrients are essential often have better fortune. It's a similar story for flow/distribution, CO2, lighting and cleanliness. While there are many ways to skin the cat, as long as the basic principles are adhered to the hobbyist will have a better chance of success. I'm probably one of the worst offenders of the excessive PAR rule, but I also have a firm grip on how to mitigate the dangers. As I mentioned, significantly improving all the other items on the list first, and bringing the plants back to a state of good health, will then enable you to increase the energy levels.

The chart shown can be used as a guide. The curves drawn are for single bulbs. PC refers to Power Compact bulbs. So if you have two of these bulbs, then 12 inches down from the surface of the bulbs the PAR is approximately 2 x 50 = 100 micromoles. You really should aim for a total of about 40-50 micromoles. Now that's only at the substrate level. Higher up in the tank, since the distance from the bulb is shorter, the PAR levels rise adding even more stress.

Here is L. glandulosa under a 4 PC fixture approximately 20 inches from the bulb surface. No problems. The leaves are flat and clean.

This is the same specimen after it had grown to within 6 inches of the bulbs. You can see how the leaves are crinkled and distorted. Under this lighting stress, the amount of CO2 necessary to flatten the leaves out again was simply uneconomical.

The only real way of knowing what the PAR levels are is to directly measure them with a PAR meter. As you deduced, this illustrates that X wpg in one tank is rarely the same as X wpg in another tank, because there are some influential variables. The wpg rule totally breaks down in very small and very large tanks because the energy levels are a partial function of distance from the bulb. Having total control of lighting, as well as of flow/distribution/CO2 is in a way a sort of Holy Grail.

Cheers,

 

[CrispyCod]

Hi Ceg,

Thanks for that, very informative images as well, it is clear that i need to reduce my PAR, and that the results achieved by others at 3WPG, likely had a significant difference in PAR to myself, that was the point I missed and thanks for setting me straight.

Just a comment, it is interesting to note that the tutorials on here regarding EI and C02 discuss the lighting aspect in WPG, And state the tests were conducted at a maximum level of 5-6WPG. That can be misleading (it was for me!) What was that in PAR? Quoting it in PAR, and in conjunction with the chart above, could be a much more useful way of gauging levels within a system?

Hope that makes some kind of sense!

Just to clarify, I have an Arcadia Luminaire with 2 T5Ho at 54Watts each, so probably higher than the 100 level (oops, highly ridiculous levels, now that I know.)

Thanks

Chris

 

[ceg4048]

Hi Chris,
Tom Barr did the experiments and he hasn't supplied any PAR data. That's a good question though and I'll have to see if he recorded the data. The thing to remember though is that Tom was already an expert at growing plants. Understanding the physiology of plants is his vocation, so in the tanks he would have already implemented the very same principles of high flow good distribution and excellent CO2, so that light would not have been that much of an impediment. He made the flow, and \co2 adjustments as he increased the intensity levels. In fact, in my tutorial, near the bottom, I alluded to this by inserting the following paragraph:

Won't all these nutrients cause algae?
It's important to be aware that there are a variety of factors that can bring the onset of algal blooms which are not related to the dosing scheme. The following are typical causal factors:
1. Poor CO2 injection methods
2. Poor flow distribution within the tank.
3. Poor tank maintenance, i.e. not cleaning filters or detritus buildup in tank.
4. Overfeeding.
5. Excessive disturbance of the substrate.

The object lesson was that the nutrient dosing program can never save you from all the other mishaps of poor plant husbandry, and that these issues can occur regardless of the lighting or the nutrient dosing. EI only addresses plant health issues due to nutrient defficiency, so that was the focus of article. It's difficult to cover every single aspect of plant husbandry in any one article, so lighting has it's own article, as does pruning, tank setup and CO2 application.

Again, remember that we are not saying that you can't successfully implement a 150 micromole tank, only that you need to rigorously address the flow and CO2. The EI tank used in the article had half a Kilowatt of T5 PC over 150 USG, and the tank was in almost full sunlight sitting in a conservatory that had daytime air temperatures exceeding 40 degrees C, which added even more energy, but I did not start the tank out that way. I started with low energy, got the plants super healthy, maximized the flow/distribution and CO2 and then ramped the lighting up when I knew the tank could handle the excessive lighting stress.


Cheers,