All,

Just wanted to see if I am way off base here... I am reading some other sites (I won't mention which ones, but they are quite popular) and it seems like they toss out fertilization recommendations at random. For some plants they recommend low nitrates, others high nitrates etc... etc... Some quotes as examples:

In regards to L. repens:
"Lean nitrate levels (~5 ppm), high phosphate levels (~1.5-2 ppm), and heavy iron/micronutrients dosing will help produce intense colors out of this plant. Some hobbyists have noted that 9325K plant bulbs will also enhance red coloration."

In regards to Rotala Macrandra
"If nitrate is pushed too high (20 ppm or more), the plant may actually stunt. Low NO3 levels (10 ppm or less) coupled with high PO4 levels (1.5 to 2 ppm) lead to very compact, lush, bright red growth."

Is there any truth to such statements? They seem kind of random/un-founded. It is my understanding some emersed plants change color etc... in different soil PHs and some plants will produce more flowers compared to fruit when NO3 levels are high. Not sure if this translates to statements such as above.

I am going to try the L. Repens myself and see what I come up with using EI.

Cheers,
John

I don't know much, but my bs meter went up when I read your post. I think I know what Tom would say. Where's the proof based on controlled studies ?

Henry

It may not all be BS. I know that sunset hygro and rotala rotundifolia will turn a nice pink shade in low nitrates. If what was said about R. macrandra is true it would explain why it refuses to grow in my tank with 2.75wpg, EI dosing and pressurized CO2. While the same plants grow great in my LFS tank that gets no CO2 and hardly any ferts.

I was the one that first put forth the color change hypothesis with low NO3's in the hobby and then 3-4 of us shown it.
Others followed there after, but folks ran very low NO3 for a long time, they ran into issues when the NO3 bottomed out and with poor testign and poor test methods for such low NO3's readings.

So luck was involved in many successful cases. Lower light seemed to help, limiting PO4 was suggested again as a way to reduce the NO3 demand and maintain a low NO3 without stunting.

As fas as R macrandra getting stunted at high NO3?
Total crap.

I have it at 30ppm and it's a weed.
Always has been.

I'm not sure red color is desirable for plants though, they do not grow as well/fast, it's a sign of N stress in many species, not health.

Put another way:
Is a bony skinny 1/2 starved dog aesthetic?
Bony starved super model?
Starved plant?

Depends on your perception, all cases involved stressed animals/peoples/plants. How you rationalize your moral choice is more subjective, but I try to not make such conflicting choices if possible.

Many plants will do very well and look nice a red with higher GH's also as well as more traces, good CO2 and even less light.


Regards,
Tom Barr

Hi Tom, as a number of us are having difficulty growing rotala macrandra and wallichii (both supposedly soft water plants) with EI dosing, can you please provide details of the conditions that you grow them under. i.e Gh, Kh, NO3, PO4, Iron and WPG. And if possible post some pics of them.

Thanks

Softer water seems to make both of these easier to grow IME.
It's not madatory, but they do better.

Color is better when we add more GH booster also but not KH.

This is a general consensus after what? 10 years of the local club growing and doing very well with the plant, Neil sending gobs of it for sale for over 20 years etc.

Other than that, high nutrients sends these plants into over drive.

I think CO2 is the most problematic issue for most folks having issues, and if that's not it, then it's just consistent dosing/CO2/routines/lower KH.

If you apply CO2 mist directly on the plant, they should grow very well in most conditions.(rules out CO2 as an issue)

Regards,
Tom Barr