hygrophila polysperma

[clutterydrawer]

I got some Hygrophila Polysperma for my tank a while ago. It's grown really fast and seemed healthy.

Recently, the highest leaves, which have reached the surface of the water, have started turning pink. Why are they doing this, and is it good or bad? There are a couple of pics here and here so you can see what I mean.

 

[Lateral Line]

Many plants start to show pinky-red colouration as they near the surface under good light. The reason is the plant needs less chlorophyll in these leaves to photosynthesise. The bright green chlorophyll normally masks the more subtle pink - red alkyloid, flavinoid and carotinoid pigments which are always there, just not seen.

If you nip these pink shoots off and plant them, (assuming they survive - don't damage the stems), they will normally "loose" the pink colouration as the chlorophyll level rises again. When they reach the brighter light at the surface, it returns.

The is a special cultivar of H. polysperma called "Rosanervig" which shows this pink colouration more, but it is a higher light demanding cultivar.

 

[clutterydrawer]

sweet

I thought it might be something to do with the light but I wasn't sure that my light was strong enough to have such effect cos I only have 1wpg

thankyou!

 

[gale]

Glad you asked because mine are doing the same thing.

 

[Barday]

Same with mine!

 

[Discomafia]

I third that!

 

[konrad05]

Mine do too, but at like half way to the surface. Apparently the white vessels in the leaves is a virus of some sort that doesn't spread or harm the plant. But the pink looks nice

 

[clutterydrawer]

Haha yes I am well chuffed that I've got pink plants when I'm only running 1wpg. who woulda thought it?

 

[Sanj]

Remember though if you are using UK gallons you are prob using a bit more than 1wpg(US) which dominate the web.

 

[clutterydrawer]

I'm not using UK gallons.

 

[daddyo72]

Hygrophila polysperma
Hygrophila polysperma in my aquarium
Emerse form of Hygrophila polysperma

Common name
Dwarf hygrophila

Synonymies
Justicia polysperma, Ruellia polysperma, Heliadelphis polysperma.

Description
Fast growing stem plant. If well lighted the leaves are colored a bit red-brown. Is often mentioned thé best plant for the aquarium. The first hotograph on this page shows how the plant looks in my aquarium at this time, while the second photograph shows the emers form of this plant.

My experiences
In the years I have my aquarium, I've had this plant in my aquarium for a couple of times. Often this plant grew very good (and fast) for a while and formed a lot of side shoots. But for some reason when this plant stands on the same spot for a long time it suddenly dies after I while. Personally I think the plants pollute the bottom in a way that they can't grow there anymore for a while, although I never managed to find anything about this in books or on the Internet. When I place plants of another specie on these spots they always grow normal.
Place and lighting in my aquarium
This plant has stood on the right-back and mid-back of my aquarium. The lighting I used at the time was a 0.42 Watt/liter lumilux TL lighting (2*18 Watt).