Plant Coloration Strategies

OK so I figured that this should be in the advanced strategies section because I hope that this thread will eventually be a strategy to bring out plant color.

My favorite genus of plants is Rotala............. currently I have two 10g tanks devoted just to these plants. Both tanks have aquasoil as the substrate, use a drop checker to show CO2 levels and have 36watt AH supply light systems with 6700K bulbs. Additionally I use RO water on both tanks (50% WC weekly with 1/2 tsp GHbooster). The diferences between the tanks are the fertilization methods used and the filter. On tank number 1 I use a canister filter and ADA products and on tank number 2 I use EI dosing and a hang on back filter. I don't think the filter matters except that tank number two uses more bubles per second to maintain the proper CO2 level so the only difference between the tanks is truly the fertilization method used. For the record the aquasoil is several years old so I doubt it has any nutrients left in it (well at least in the ADA dosing side)......both tanks are fish free also so no nutrients go in except what I dose.

So with all that stuff out of the way I would like to share my experience and follow with a few questions. Tank number one has super red plants and slower plant growth. Tank number two has way faster plant growth but alot of the plants show way less red / orange coloration. I assume this to be because I am severly limiting the nitrogen supply to the plants in tank number 1 (I only give the tank 2 pumps of Lights 3x weekly which equals about 1-2ppm weekly). This is most evident with the wallichii and the sp. colorata. In the nutrient limited tank 1, the colorata is super pink / red while in the EI tank the new growth is completely green while the older growth has some red coloration but not very intense (I will post photos sometime this week if I get a chance).

So here is my question.......how can you increase red coloration of plants while still using the EI method????? Is this even possible?

My assumtion(s) here (which could be completely wrong) is/are that red coloration is due to the accessory pigments that collect light and these pigments are produced to either 1) collect more light in lower lights systems (light limited) or 2) collect light when chlorophyll cannot be made (nutrient limited).

If this is true is there any way besides either starving the plants or reducing light to trick the plants to produce more of these accessory pigments?

Isn't it a myth that adding more iron will increase coloration?

What about adding Ca or Mg.........would increasing GH help coloration?



This was posted by tom a while back:

"Not sure about individual coloration with respect to each , Mg and Ca.

But with both, it seesm higher GH's seem to help.
Likely due to enzymes that make the red colored pigments.

In ADA soil and soft water, the plants are nice and grow well, but are pale.
I get blood red color with less light and more GH."




Thanks in advance for any help / discussion,

Ken T.

 

Hi Matt,

First let me correct something that you posted. Tank 1 is nutrient limited and slower growing.....tank 2 uses EI and is faster growing.......maybe that was just a mistype on your part

As for your thoughts:

Thought 1) I do not know if plants turn more red the closer to the light they get.......that would indicate that the more light the plant gets the redder it gets which I personnally thought was a myth.....maybe someone else can answer that. I have never let the plants get to the top of the tank because I usually trim them to keep better circulation. Maybe that will be the next thing I do. I somehow doubt this will be the case, however I will let the the plants in the EI tank (tank 2) to grow all the way to the top in the next week or two to see if they becomoe more red. (good idea on your part). I can tell you that when the plants are towards the bottom of the tank and toward the middle of the tank the nutrient limited plants are way redder (is redder even a word????)

Thought 2) I thought I read in a post by tom that new growth is usuall pale in faster growing plants......or maybe it was the other way around....I have been looking for that post for 2 days now and can't find it. I cannot answer that question.......I was hoping it would be brought up though and I thank you for reminding me about it............Tom any answers????

Ken T.

 

Since my GH is only 1-2 max I will increase it to 4 or more and see what happens. If more red colors come out then we can definitively say that a higher GH is better for coloration (at least I will believe it )

I will let every one know in a few weeks.....I will increase the GH after this weeks' waterchange (this Sunday).

Maybe I should take before and after photos......I will take some before photos tonight and maybe post them tomorrow.

Anyone know how to post photos?????

 

colorata photos

OK so here are the photos.

The first photo is from Tank 1 (the ADA, nutrient limited tank):



This second image is from Tank 2 (the EI tank):



The photos were taken with the same white balance (fluorescent) and no colorchanges were done in PS.....just some cropping and changing image size. The lighting on both tanks are 6700K made by the same company and use AH supply reflectors (basically the light source is the exact same as far as I know.......no scientific instruments used to measure however)

These photos also do no justice to the plants themselves. The red is much more vibrant in Tank 1, and the green of the plants in Tank 2 is about the same colora as Rotala sp. green. Oh yeah, both plants are Rotala sp. colorata, just grown in different tanks under different nutrient conditions.

These photos are just to show the current coloration differences. I will also try to post an after photo in a few weeks of the plants in Tank 2.........after I add more GH and if there actually is a color change.

Ken T.

Did I forget anything????

 

Hey Tom,

In the EI tank I already dose what I would consider heavy dosing. I dose CSM+b plus extra iron (a mix that Greg used to sell pre-mixed and that I actually just recently emailed him about to find out what was in it because I am running out of it and need to make more..........that is unless you magically release your trace mix this week ). sorry to go on a tangent there........I dose 1/16 tsp 3x weekly (dry) as well as 2ml Flourish 3x weekly. Would you consider this heavy micronutrient dosing????? If so the only 2 real variables, since all nutrients should be in excess (macros and micros), is the lighting amount and the GH. If I raise GH to your recommendations and the plants still do not become red than we can eliminate it down to the Light......in which case a 36W bulb with AHsupply reflector over a 10g tank would be too intense lighting to allow the reds to develop. Would you agree????

Laters,

KT

 

Hi Tom,

Actually and suprisingly yes....the ADA aquasoil is from the same bag so it is the same aquasoil.......both are about 2 1/2 years old......the differences being the method of dosing.

You are correct however, I am assuming that the plants from tank 1 are nutrient limited.....I haven't actually tested it. I am basing this assumption on the fact that I sincerely belive that Aquasoil in no way shape or form has enough nutrients in it to grow plants for 2 1/2 years.

A good test for this however would be to start EI dosing on Tank 1......if the plants start to grow green than we can once again assume (without testing) that it was due to nutrient limitation.

The plants are both located directly under the light in the middle of the tanks. Your are correct however, I do not have a light meter so I do not know for sure that bothe lights are identical......they do however use the same bulb with the same reflector. I will admit however the bulb used in tank 2 is about 3 months older.

As for the plant health....once again the photos do no justice. The plants in Tank 2 are way more healthy, never stunt or show twisted leaves and grow about 3-4 x faster. On the other hand the red plants in Tank 1 will stunt once in a while namely if I don't give them at least a few pumps of macros a few times a week. These plants grow extremely slow.

For the record, I am not condoning the use of limiting nutrients to promote red coloration. I simply would like to know if there is a way to promote it without having to limit it.

Ken T.

P.S. If you look real closely in the photo of Tank 1, you can see some algae........a clear indication that the conditions in tank 2 are better

 

Hi Tom,

I don't know if you understand what I am saying.

What I am saying is that the tank to which I dose EI (tank 2) has no algae growth and great plant growth......NO TWISTED LEAVES. It only has less intense red coloration. I think this is due to one of two things.........Too much light, or too low GH. If a add more GH than it is because the light is too intense.

The tank to which I limit NO3 (well actually all macros....Tank 1) has stunted leaves, algae, slower growth but is more red. I think this is due to nutrient limitation not CO2.

CO2 should be the same......both have drop checkers that use the same 4KH solution and are both green.

There are two simple tests that I can do........the first test would be to switch the tank (tank 1) that I believe to be nutrient limited over to EI......If I do this and the platns turn green well then that shows nutrient limitation is causing the red. The other test I can do is to increase the CO2 (that is if you believe the tank is not nutrient limited and the stuntinig and red coloration is due to CO2 rather than NO3 limitation).

So tonight I will stop dosing ADA fertilizers on that tank (tank 1) and switch over to EI......If by early next week the plants that were red (in tank 1) turn green would you agree that they were nutrient limited??????

 

Hi Tom,

Last night I added EI dosing to the tank that contained the red plants (Tank 1.....the "same tank" as you say). If the plants in this tank turn green then I will believe that the red coloration was due to limiting macros......however I will do several replicates using this same tank......I will try to see if I can turn the plants red again (assuming they turn green in the next few days) by limiting the macros again......and then give them macros and see if I can turn them green again. Maybe I will not repeat this 5-6 times becuase usually in science 3 replicates is good enough for a paper so I would think that it should be good enough for a forum. I will try to post photos along the way also to show everyone what is going on.

About the light......yes I agree if I really cared about having red plants all the time I would decrease the lighting but:

1) I don't really feel like going out to replace my current fixtures
2) There would be no need to if I can just limit macros to turn them red for the photo


On a side note, maybe all this is just irrelevant anyway.....I still haven't added more GH to Tank 2 yet (the tank with the green plants).....maybe this will turn the green growing plants red. I will start this experiment on Sunday.


Laters,

KT