Question about Rotala or just red stem plants in general

[Scotthop57]

Planted some Rotala. It was grown emerged so it was green.

It’s now showing the nice thin submerged leaves but they are like coppery.

My question is for plants that turn red. If they were going to be red would new leaves start red or do they start greenish and change. I’m sure my tank is not where it needs to be to get them a nice dark red but since it’s brand new I figure I would let it get settled and everything before I start trying to tinker with it to get it more red.

So this is more of a learning question about the plants themselves and when they turn red and how they turn red.

I know there are stages but will these leaves that are a mix slowly get redder or will they just stay like that and new growth will become red once I tinker with the levels of nutrients and what not in the tank.

 

[Naturescapes_Rocco]

The two main factors for color in plants are high light, and nitrate limitation.

Red coloration in our aquatic plants evolved as a mechanism to essentially fight against sunburn (simplified explanation). However, lean nitrates in the water column (<5-10ppm NO3) also has a big effect on plant coloration, too. It's easy to run tanks with fresh, rich aquasoil in low NO3 environments, but can be harder with inert soils or old/weak aquasoil.

Increasing the strength of your light can work extremely well to increase color, but beware that it will exacerbate any imbalances in your CO2/Nutrients and cause algae much faster at high light.

If you want plants that stay red 90% of the time (at medium light or more) regardless of NO3 levels, I'd recommend Ludwigia Super Red (mini), AR Mini, and Lisimachia parvifloria. I like to run a rich water column, 20-30ppm NO3 on average at all times, and it was really difficult to get my Rotala Blood Red to turn red, despite extremely high light. Some plants, when NO3 rises above 5-10ppm, just won't get that deep red color. But these 3 species stay red red red for me, no matter what NO3 levels I run.

Here's a great article on the subject:

How to grow red aquarium plants​

 

[Naturescapes_Rocco]

Also, as your rotala stems grow taller, they get closer to the light, and will also get more color, too.

My question is for plants that turn red. If they were going to be red would new leaves start red or do they start greenish and change. I’m sure my tank is not where it needs to be to get them a nice dark red but since it’s brand new I figure I would let it get settled and everything before I start trying to tinker with it to get it more red.

Sorry, missed this question!
The old growth will likely stay green. In very few plants will the old growth turn redder with more light/less NO3, but in almost all colorful plants in this hobby, the new growth will turn more colorful as it grows.


(from the article above) Rotala H'ra under light nitrate limitation on the left (5ppm NO3 in the water column, but under stronger lighting) vs. H'ra under heavy nitrate limitation (0ppm NO3 in the water column - plants are mainly root-fed by aquasoil). There is no way to get Rotala rotundifolia varieties this uniformly red without letting NO3 bottom out over a long period of time.

In this photo you can see how the old growth on the left stayed green, while the new growth turned much more orange when nitrates were reduced to 5ppm NO3.

 

[Lensavier]

On most Rotala I’ve grown, new submerged leaves come in a greenish tone and turn red as light and nutrients push pigmentation. Stronger light usually brings the deeper reds.

 

[Lensavier]

I’ve had good luck with hardy species, and cryptocoryne wendtii has been one of the easiest for me. The one I picked up came crazy clean and settled in fast, which saved me from dealing with pests or melt. Their careful packing and prep made the whole process way less stressful for my tank.

 

[CincyScaper]

I would add that the stem plant coloration also depends a lot on what camera settings are used, ambient light settings and aquarium lighting. It also depends on whether it is being taken on when the leaves are closed vs open (i.e. daytime vs night time), since the under-surface of leaves can have different coloration (especially rotalas - i find that the undersurface is more red)

Pic done during night time with slightly different lighting (Rotala HRA on the right front, Rotala Blood red on the right back)


Pic done during daytime with slightly different light setting



Both about a week apart. Nitrates at 0.5 ppm, PAR - 50 at substrate, Co2 - 40 ppm, 60% weekly water change, APT 3/APT feast powered.

 

[ElleDee]

In my experience, if the stem is already colored up sometimes newly expanding leaves can be slightly greenish at first, developing their best color when they reach full size. But if the old growth on a stem is green and the new growth is going to be red (or redder) then the new leaves come out notably redder than the old green leaves. Fully developed leaves will not turn redder even if conditions in the tank are changed to favor red coloration, but I have seen then get a bit greener over time though.

 

[Scotthop57]

I would add that the stem plant coloration also depends a lot on what camera settings are used, ambient light settings and aquarium lighting. It also depends on whether it is being taken on when the leaves are closed vs open (i.e. daytime vs night time), since the under-surface of leaves can have different coloration (especially rotalas - i find that the undersurface is more red)

Alright this makes a lot more sense because mine definitely have a nice pinkish reddish under belly lol and look great right before the lights go off and they have closed up.