Aquatic Plant Forum banner

Rotala sp Green --what's wrong?

18639 Views 36 Replies 11 Participants Last post by  HeyPK
Throughout the year, I have had problems with supposedly one of the easiest plants to grow --Rotala sp Green. Although increasing iron/traces seemed to be the solution last year, I can't seem to replicate the same results this year. Here are the aquarium conditions:

20g long
currently 6.15 wpg PC (2x55w PCs + 1x13w PC)... I'm experimenting. :)
Symptoms actually became WORSE when temporarily switched to 2x20w NO Flos for a week (2 wpg)
Pressurized CO2 being used... CO2 triple checked to be ~30ppm
NO3: ~5-10 ppm
PO4: ~1-1.5 ppm
Flourish 3 mL daily, Flourish Trace 3 mL daily, Flourish Iron 3 mL daily = 3x7= 21 mL of each supplement every week (that should be enough!!)
GH: 9
KH: 6
No additional K+ supplementation

Symptoms: Rotala sp Green produces small leaves which curl downward and corkscrew slightly. Older leaves are very dark green. Rotala sp Nanjenshan produces very short, scanty leaves with brown dead spots of necrosis.

Plants like Blyxa japonica, Tonina fluviatilis, H. zosterifolia, Ludwigia arcuata grow well without any sign of deficiency.

I will post pictures of the symptoms in a few hours.


Here's a picture showing the Rotala sp Green. Notice the curled growth.

Close up of a stem showing the deficiency.

Individual stem.

Rotala sp Nanjenshan. The plant isn't as "fluffy" as it should be, grows slowly, and has many dead brown spots at the internodes and along the stems.
See less See more
1 - 20 of 37 Posts
My Rotala sp. "Nanjenshan" did the same thing. Despite a good fertilizer regimen and a lot of light, I ended up having to throw it out.

The pictures of your plants look distinctly yellow to me...but you said you are dosing iron. Maybe more is needed?

I have heard that Ca and Boron deficiencies will make the leaves curl, as my Nesaea is currently doing. I don't know the contents of the ferts you're using. You said the Ludwigia arcuata is fine, so it probably isn't that, but maybe dosing K (to make the Ca available) will help.
I think the yellow color of the plants is partially due to the 9325k PC bulb I have in there mixed in with the 6700k. 9325k bulbs are HORRIBLE at rendering color (CRI in the 60s).

Someone emailed me suggesting that I raise NO3 levels and double check CO2 levels. I have tried raising NO3 levels and after a couple weeks of the high NO3 levels, I noticed no noticeable change in the plants. However, I am willing to try again...

I can't raise my CO2 levels any higher at this point. Even a slight turn of the CO2 knob will cause my fish to show visible signs of stress.

More iron/Fe?

As a little experiment, I dosed extra calcium today, raising my GH/KH by 1dGH. I'll report back if I see even the slightest improvement by the end of the week.

Carlos, what kind of kit are you using for the NO3? How often are you doing the testing? At 6.15wpg of PC lightings nutrients are going to be used up very quickly and bottom out real fast imo/ime. My guess is that your NO3 is causing all this issues since you mention your CO2 is good. Hope it helps....
I've only had the current lighting up for about three days. The problem dates back way, way before I ever even thought about popping in a pair of power compacts. I will try the higher NO3s again.

I test my tank water twice a week. I formerly used an AP test kit. I am currently using the Red Sea test kit with good results as far as I can see. If I dose more, the test kit reads more nitrate. Dose less, it reads less... etc.

Any thought to increasing Ca and Mg and lowering K levels?
with the KH and GH shouldn't he have enough Ca and Mg? How are you dosing No3 exactly? 2 tbls to 500 ml dry powder, etc? I would add more root fert, since you are using eco. If you had flourite, I wonder if you would be having the same problem. With that much light, your iron, No3 and phos have to be right on. I've had the same types of problems, but its been going away with lots of no3.
No flourite wont help. My plants are doing the EXACT same thing. They just look bad. Grow funny. all that. Whats weird is my only good looking stem of it is in my 20 gallon that i pretty much ignore besides adding the nutrients. Which is almost identicle to the nutrients in my 50gallon. I suspected maybe this plant greatly prefers the red spectrum because the only big differences in the two is that i add my traces dry to the 20 gallon and in a solution in the 50 gallon.... And that my light is 8800k in my 50gallon and Aquarays in the 20 gallon. I have Miracle grow under Eco complete in the 20gallon and EW casting unboiled in the 50 gallon under Flourite. With all thoughs nutrients you would think the that substrate would be no big deal.

I have experienced the same thing with Rotala indica, although not as severe. It would only be the ocassoinal stem that did it and I would cut it off. Often one side shoot of a stem would look like yours and another from the same stem would look fine. I have no idea. I will, though, throw in a couple of my own thoughts/observations.

When this started for me I jumped on the Ca bandwagon and got some Kent's liquid calcium. Dose 4-5 mls at the wc(in a 10 gallon, 4.5 watts and CO2) of the Calcium. I have a Gh of 9 so i shoul dalready have enough Ca. I have/had been raising my kH from 2 to 4 with baking soda. I am strongly associating this problem with an Na buildup.

I also was dosing more Flourish/Fe than now, although not nearly the levels you are. Only 1-2 ml every day for me. Maybe you are having a nutrient toxcicity situation? How often are your wc's. I assume 50% once a week. Could this problem be a buildup of some unusual nutrient(vandium or something silly like that)? Since this Rotala is suposedly so easy to grow, this theory could make some sense. Leave it alone and it grows fine, let NO3 climb, P drop and it is fine; start going "high tech" and the plants suffers? Maybe it is more sensitive to higher trace buildup? This does not make much sense though, Shane is dosing both his tanks the same.

Lighting... well one never knows but I had this problem before switchng to 9325k bulbs so....and not now.

K, well I do and always have dosed 10ppm of K2SO4 at the wc.

Well anyway, no answers but maybe some clues. If nothing else, you can just add this to the mix:)
See less See more
NO3, double what you are using, I add 1/4 teaspoon/20 gal tank every other day or so for this weed at high light(5.5w/gal).

It does better and grows easier at less light, like most plants. There's more wiggle room with less light. Then you can add less NO3 etc.

If you are having trouble with some of these plants, try more KNO3.

The plants will take it from the water column.
I found this plants to fun but a bit too invasive/fast growing for what I want at the moment but has it's uses certainly. Easy to grow but at high light, it likes good NO3 levels, same can be said for a few other plants.

You folks with all that light might want to add 1.5-2x more KNO3. I think you will find along with weekly 50% water changes that the plants will do quite well that you are having trouble with.

Try it for 2-3 weeks and see for yourself. Instead of adding 1/4 teaspoon 2x a week etc, add it every other day.

Tom Barr
See less See more
Error, you threw away your R. sp. "Nanjenshan"?!! :shock: :cry:
Tsunami, please keep us updated with your plants. I want to see how it reacts to the changes.
Tom. For awhile my nitrates were somewhere around 30-40, hard to tell. What do you suggest i try if nitrate is not the issue?
How sure are you that NO3 are not the issue?
How sure are you that CO2 is not the issue?
How sure are you that these are constant?

If a plant is growing along fine, then suddenly you stunt it, some species do not recover quickly, some do, some are tolerant.

I think many folks go through a peroid where the levels of CO2 or NO3 dip too low and then the plants need recovery time.
Meanwhile algae will sometimes creep in.

Even if the other plants appear fine, one plant species may find if difficult to start up again.

Plants are fairly tolerant of PO4 limitation. Same can be said for traces and K+.

Ca/Mg somewhat, NO3 and CO2 cause much more impact.
You can always do large water changes and dose with KNO3 to make certain the NO3 is what you think it is and then double check the CO2.

Tom Barr
See less See more
Tom, (not to hijack the thread of course; but out of curiosity)

How much PO4 per day or week are you adding to that 5.5wpg 20 gallon you mentioned?
I add it every other day like the KNO3. About .5-.8ppm each time I dose.
Doesn't really matter, the tank is not limited.
Large 50-70% water changes reduce things back down.

As long as I don't limit things, I have no issues. The tank is light limited I would suppose or another way of looking at it: "max light use efficiency"

Tom Barr
plantbrain said:
I add it every other day like the KNO3. About .5-.8ppm each time I dose.
Doesn't really matter, the tank is not limited.
Large 50-70% water changes reduce things back down.

As long as I don't limit things, I have no issues. The tank is light limited I would suppose or another way of looking at it: "max light use efficiency"

Tom Barr
I was actually looking for a quantity. I have a similar tank and would like to know how much PO4 to does. I am using Mono Potassium Phosphate.
I use a small spoon from the lab that hits about this range, you might want to measure out some method of dosing it dry if you want more accuracy or add some to DI water and dose the liquid that way.

I don't have a need to be that accurate really any more with PO4. I've done enough with PO4 over the last few years. It's not as critical if allowed to get too low or gets fairly high as many other nutrients.

Tom Barr
Ok, it's been 5 days since I've increased NO3 levels. There have already been some major changes in the morphology of several plants. My "purple strain" Limnophila aromatica has tranformed from a beautiful lilac color to lime green. My Ludwigia arcuata is now orange. The Rotala sp Nanjenshan has shown signs of new, healthy growth (about an inch so far). On the flip side, the Rotala macrandra 'narrow leaf' grew very large leaves in the beginning of the week but has since begun stunting.

Most importantly, although the internodes and growth rate of the Rotala sp Green have both increased tremendously, the leaves are still small and curved downward like in the photo. Some stems have stunted even more, showing some transparent patches on the newest leaves along with the twisting.

Is Rotala sp Green really so nitrate demanding? My usual nitrate indicators --Micranthemum umbrosum, Hottonia palustris, and Heteranthera zosterifolia --grow very large, lush, deep green leaves in all the conditions I've tried growing Rotala sp Green in.

Rotala sp Nanjenshan is recovering? Still looks yellowish. Then again, all my green plants look yellow under the 9325k bulb.

One of my nutrient indicators. Showing very large foliage.

Rotala sp Green still looks horrendous, although growth has quickened and the plant is shooting out many, many sideshoots.

The entire tank has lost a lot of "sparkle" and seems "dirty." A lot of the bottom portions of the plants show considerably amounts of algae.

See less See more
Carlos, give the plants more time to recover. Some may bounce back immediately but others might take more time.
I'm glad you tried upping the NO3. Keep with it for about 3 weeks and then see what you think.

I'm not 100% certain it's NO3 but it might be the K+ also + NO3.

If you like the lower NO3 colors, you can drop the NO3 down for a couple of day etc and get the "red in" take the photo, show your buddies etc then go back to faster growth.

You can also try limiting the PO4 more so that it slows down the NO3 uptake some and make it easier to maintain a lower level at higher light without bottoming out.
To this same effect, one can do this with less light as well.

This can allow good reds with easier wiggle room with NO3/NH4(fish sources at lower light have a larger % on the total N used by plants).

But I think running at higher NO3 for SOME plants might be needed.
Stunting has always been associated with bottoming out the NO3.
Some plants are more sensitive to it and instead of dying/melting etc, they just stunt and wait till the conditions are better and then start growing again.

Some plants seem to need more NO3 than others, wheat for example prefers NO3, not NH4. Sionme aquatic plants like Crypts can handle very low NO3 while Mic umbrosum may need 5-10x as much to grow well.

But few plants seem stunted by too many nutrients.
Perhpas that was what the whole high K+/Ca thing was all about it.

CO2 and NO3 are the two big players.

Tom Barr
See less See more
1 - 20 of 37 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.