[rjfurbank]

Here are some pics of my Rotala macranda--not sure if this is a nutrient deficiency or algae.

From this sticky it appears it may be nitrogen deficiency?

http://www.aquaticplantcentral.com/forumapc/fertilizing/62876-plant-deficiency-picture-diagram.html

However, near the bottom of the stem there is some new branching shoots that look good (didn't get a pic of this--may add later).

What do you think???

My current dosing regimen for this 90g tank: (dosed every other day; tap water = gH ~9; kH ~6; pH ~7.6)
-0.5 tsp KNO3
-0.125 tsp KH2PO4
-0.5 tsp K2SO4
-20mL Flourish
-CO2 pressurized--on w/ lights--drop checker light green to yellow

I routinely measure N using my test kit (API) at 10-20 ppm.

Thanks,

-Roy

 

[ashappard]

looks like deficiency / stunt - whatever is appropriate to call it when R.macrandra does this.
Try backing off on the N and increasing the P
it should respond with better growth and nicer leaves.

keep N and P in a tighter ratio (closer together, like 10ppm N 3 ppm P) for best appearance on R.macrandra. IME the leaves that are ugly will probably stay that way. Not always but usually. New growth will look better once conditions improve. Dont forget to keep Iron and traces available.

try to keep levels of nutrients as constant as possible. I use daily dosing when consistency is important; traces then macros a few hours later.

 

[rjfurbank]

Thanks for the detailed response ashappard! Was beginning to wonder if I would get any. . .

I will give this a shot--I recently started dosing less P b/c I thought I was getting a build up from fish food and dosing--was focusing on keeping it ~>1 and the N between 10-20. Will up the P again and see how that works. Are you sure 3 ppm is not too high?

Thanks again!

-Roy

 

[ashappard]

I cant guarantee that its not too high

As long at N and traces are available you should not have problems with stability.
Move P up slowly if you like, probably not a bad idea. Just make sure more is available each day until you hit your target. The R.macrandras with larger red leaves seem to do best with moderate N and elevated P. Hopefully this regime wont cause issues with other spp. - I've had that problem before and had to adjust dosing or move plants to around. Good luck!

 

[Zapins]

Hmm, I agree something is off with the mac. Nitrogen is probably the likely culprit. But I'm not convinced that its because its too high. Can you verify the actual N level with a test. It almost looks like very early boron deficiency with the green spots on the leaves and the slightly curled new leaves. On the other hand boron deficiency is rare as deficiencies go, but it does show up first in rotala species, especially macrandra.

 

[Newt]

Check out the attachments:

 

[ashappard]

thing is guys, not all spp fit nicely into these deficiency charts.
for example, add lots of baking soda to your Tonina tank (gasp!) and watch the stems suffer.
now find the cause and solution on the deficiency chart

for macros : ~10ppm of N and ~2-3ppm of P makes R.macrandra look real nice. R.macrandra's difficulty is in its narrow range of acceptable levels for best appearance. Not far outside the range is stunting and ugly leaves. I use commercial liquid mixes for traces, dosed daily those cover boron, cobalt, etc.

R.mac likes the iron also, but without P it cant look nice.
you can skip the difficulty/reliability of test kits and dose by addition (+xppm per day)
with good stock solutions and known base water you can keep even the most difficult spp.

 

[rjfurbank]

Thanks everyone for the input (and the links Newt!). Looks like the consensus is that it is NOT algae but some nutrient deficiency. That's good to know--and hopefully easier to correct.

ashappard's thoughts are supported by a recent change in my dosing. I thought my P was too high (routinely measured between 2-5 ppm on my API test kits) so I recently (~1 week before observing the deficiency) began dosing less to try to keep it ~0.5. I have since returned to my normal dosing and the levels I measured last night were N = 10 and P = 2. My N levels have been fairly constant and kept routinely 10>N>20.

I have also started dosing iron on my alternate days (usually dose micros and macros every other day) and the color is a lot more red. Shortly after the pics I took i trimmed and replanted the tops and the color is much improved--however the green spots are still present.

Another question: if I correct the deficiency will the green spots disappear or are those leaves done for?

PS--all the other plants in the aquarium seem fine (many species in this 90g tank--see my journal: http://www.aquaticplantcentral.com/forumapc/journals/59863-rjfurbank-s-90g-journal-5.html)

 

[ashappard]

Another question: if I correct the deficiency will the green spots disappear or are those leaves done for?

PS--all the other plants in the aquarium seem fine (many species in this 90g tank--see my journal: http://www.aquaticplantcentral.com/forumapc/journals/59863-rjfurbank-s-90g-journal-5.html)

the unsightly leaves may be toast, but new growth is the concern - going forward if R.mac is happy it will make many attractive shoots and you can remove the other stuff. If you keep P up, it will be more compact and less likely to shoot to the top (internodes will be much shorter).

I've noticed the same thing, when R.mac stunts other plants will chug along just fine but this is attributed to the different requirements between species. Some plants are good indicators of general instability or dosing problems, some are just picky about ranges. The latter usually end up in the 'difficult' category.

 

[Zapins]

Any update on how this problem turned out? I know its been a few years but it would still be interesting to know. Definitely looks like nitrogen deficiency, especially with the old leaf deterioration and the new leaf smaller size.