Red plants being Green.

Skippy · 12-16-2002, 1:26 AM

I recently acquired some "red" plants of various types (Red Wendtii, Rotala macrandra, and two other red stem plants i'm still looking up the exact names for. )

They are all growing very nicely in my 100g tank, (2wpg and pressurized c02), but the newer growth is coming in more of a green coloration than red. Is this normal for "red" type plants? I am unfamiliar with what makes certain plants red so I'm not sure.

I will work on getting those other two exact names.

Richer · 12-16-2002, 1:46 AM

Funny, my experiences with color changing plants are opposite from yours. I was at the LFS a couple weeks ago and the owner sold me a mass of clippings for almost nothing (there are two distinct plants but I can't identify them). Anyways, both plants were green to begin with, but as time went by one of them started to get really red... especially near the tops of the plant. The other one got a slight red tint on the edge of its leaves. After some researching and asking around, I finally figured that it was because of the lighting I had that caused the plants to go red (220 watts over 70 gallons.. slightly more thant 3wpg).
If I remember correctly, there is also a nutrient that you can limit that can cause a plant to go red... (nitrate maybe?). I believe Tom Barr knows what it is... I'll look around to see if I can find out.

HTH
-Richer

Richer · 12-16-2002, 1:51 AM

Here we go...

Quote:

Originally posted by plantbrain
Rotala's certainly turn red when you let the NO3 get down low and most other nutrients are high. Ludwigia(most) are the same. L granulosus, repens, and arcurata do this.
But folks sometimes take the NO3 limitation too far and kill the plant.
Iron can be some of it, but I can easily turn a number of red plants green by adding nitrogen.
It's not one single element but serveral that get your plants in great shape.
Each nutrient that you are able to get within a good range brings you one step closer to having your goal. It also allows you to have more flexibilty in your routine if all the other nutrients are in good shape. Light, CO2, K, PO4, traces are fairly easy to get in a nice range but folks many times don't go back and make sure these are in good shape.

Many don't know what the PO4 is at all.
Most have CO2 issues(not enough) especially those that use DIY C02.
Many test with poor NO3 test kits.

One thing that works well for me is having a semi low fish load that gets feed regularly, and adding everything except the KNO3 except at 1/2 doses 2x a week.
I get decent results, don't toast the plants, easy routine, does't involve lots of testing to keep things going.

But it depends on your fish load/tap etc. Some tweaking is required.

Bottom line is to keep the NO3 pretty low.
Add KNO3 and you can watch the red turn green in about 1-2 days.

Regards,
Tom Barr

HTH
-Richer

Skippy · 12-16-2002, 4:32 AM

Wow, thanks.

I need to get some new test kits for this tank soon. I am missing a few and have run out of some so have been "winging it" until after the first.

Also I promised my girlfriend no more fish toys until after the holidays. heh

Skippy · 12-16-2002, 5:40 AM

But I suppose that looking at that strong new growth, even if green, should indicate a healthy water column with enough nutrients, I think....

carpguy · 12-16-2002, 7:04 AM

Here is an interesting thread on rotala indica over at AquaBotanic. Down towards the bottom it discusses growth and color. Some folks had sufficient light but weren't getting red growth. Maintaining nutrient levels esp. phosphate and keeping nitrates low were both cited. It mostly agrees with Richer's Plantbrain quote, but there is some other detail worth reading.

A good info site for plants, if you haven't stumbled across it yet.

plantbrain · 12-16-2002, 11:28 AM

Your tank sounds good and the NO3 maybe a bit on the high side.
Most things you've said indicate the NO3 are higher than 5-10ppm.
You can do a water change to reduce them or else increase the % of water changes that you presently do from say 25% weekly to 50% weekly.

Lighting is relevant in content of the avialable nutrients, if there's not enough nutrients at high lighting and/or the plants cannot assimilate the nutrient fast enough, then the color is variable.

At lower light and high nutients except for NO3, red color does come out nicely in virtually all plants.

Generally at high light, getting good red color with anumber of plants can be somewhat tricky.
You either have too much NO3, and green plants, or you have too little and stunt your plant's growth.
Depending on the balance of nutrients, lighting may or may NOT effect color.
There is no simple answer to this issue. A number of nutrients AND light plays a role.
At 2w/gal that should be enough for great color on most all plants.

It's like a drug, too much kills the patient, too little has no effect.

Regards,
Tom Barr

djlen · 12-16-2002, 12:09 PM

Following Tom Barr is an impossible task, but I'll share my experience with Rotala and red Crypts.....most of my parameters being very similar to yours, when I keep my NO3 at 10ppm they come up nice and red.
Len

Skippy · 12-17-2002, 12:09 AM

Wow, thanks guys!

Well, the tank is due for a water change on thursday anyways, and I will be testing for NO3 content before and after the change.

Then I suppose I'll wait a week anyway since my tank play time is going to be seriously cut down with my holiday family visiting schedule.

So hopefully that will get them to redden up some.