Amazon sword new leaves look a little translucent

[Andrew waterson]

Hi All,

A question about my Amazon swords, I don't have much experience with aquarium plants

They seem to be growing well (flowering stalks have grown out of the tank!) and lots of new leaves.
The new leaves look healthy but they are a bit see through (still green, but I can see the shadow of my fingers through them unlike the grown leaves).
Is this just what new leaves look like and they thicken up as they grow or is there a deficiency in the tank?

I've got a 150L tank with 2 30w tubes (so certainly on the low light level) that are on for approx 12hrs a day
I use root tabs in the gravel (easy life root sticks)
Water is hard (GH 19) alkaline (PH 8.2)
ammonia and nitrite 0, nitrate is approx 20ppm (as per my tap water + the API kit is impossible to read!)
Fish are all small community fish (dwarf rainbows, zebra danios, bronze cory's and a pearl gourami)

Any help appreciated!

 

[Byron]

What you describe may be normal. If they develop and the plants are enormous with inflorescences as you mention I wouldn't worry.

Your light may not be low...what type of tubes are they (meaning, T8 or T5), and what is the spectrum (the number with a "K" suffix)?

The substrate tabs are ideal for swords because these plants (Echinodorus species) are heavy feeders, and substrate fertilizers do not get into the upper water column like liquid, so algae issues are not so likely. I use Flourish Tabs (Seachem) so don't know anything about the Easy Life and the web site does not indicate the ingredients (minerals and nutrients) but they are probably much the same.

 

[Colin_T]

If you are not getting much algae, you can increase the photoperiod a couple more hours to increase the light the plants get. You can have lights on for up to 16 hours per day, but increase it an hour or two and see how the algae and plant goes.

 

[Andrew waterson]

Its a T8 (interpet) , the spectrum is list listed in wavelength nm and is approx 660nm (I think that's in the red spectrum?)
I can't see a K rating on the manual, they have 780 lumen and 7,000 h?

I don't think there suppose to be that good, but came as part of the package (hood lighting built in) so replacing them with T5's wasn't an option
Think I might get T8 LED lights eventually, the Arcadia ones have 8k is that a good thing?

 

[Colin_T]

Lights with 8K (K is for Kelvin) are too high for plants. Anything above 6500K is unnecessary for aquatic plants and 8K is more for making corals luminesce in marine tanks. 10,000K is ultraviolet light that causes sunburn and it makes corals glow.

Sunlight during the middle of the day has a 6500K rating and that is what you want. As the Kelvin rating increases above 6500K, the amount of blue and ultraviolet light increases and becomes the predominant colour of light.

As the Kelvin rating drops below 5500K, you get more red and yellow light and less blue.

Plants primarily use red and blue and if they don't get both they don't do as well. Lights also lose their Kelvin rating over time so a 6500K globe will be closer to 5500K after 6 months, and might be around 4500K after 12 months.

Most aquarium globes have some red and some blue light but any light with a 6500K rating will be fine.

 

[Byron]

Its a T8 (interpet) , the spectrum is list listed in wavelength nm and is approx 660nm (I think that's in the red spectrum?)
I can't see a K rating on the manual, they have 780 lumen and 7,000 h?

I don't think there suppose to be that good, but came as part of the package (hood lighting built in) so replacing them with T5's wasn't an option
Think I might get T8 LED lights eventually, the Arcadia ones have 8k is that a good thing?

No to the last question, if 8000K is the spectrum; this has too little red (almost none) and red is the prime driver of photosynthesis. I don't say much on LED as my five attempts were failures and the units went back. I stay with T8 which I know, though getting T8 fixtures these days is not easy (depending where you are) and one may have to build/rebuild which is what I did when the originals gave out.

So far as I know, 660nm is in the red, which is fine for your plants, though you do want some blue and green to balance. This is why light in the 5000K to 7000K range is so good; around 6000K is very close to mid-day sun and not only encourages plants but provides a more true colour rendition of fish and plants.

I would not recommend T5 fluorescent light. This is much more intense lighting, and compared to what you now have, if the plants are responding as well as you indicate, you would have a real problem with algae.

I would not increase the photoperiod. First, longer light periods cannot compensate for intensity, so this may encourage algae but nothing else. Also, you want a more balanced day/night period, which is not only better for plants buty also fish; light's effects on forest fish is considerable.

 

[Andrew waterson]

Thanks both, that is a great help (as always!)
I'll stick with the lights as is and keep up with the root tabs.
Hopefully they'll thicken a bit as they grow.

I do have a bit of algea that I'm cleaning of every few weeks, mostly just a bit of green film on the glass but a few patches of black beard that I'm keeping a close eye on.
The tank is only a few months old so still settling in
Also I think I over feed a bit, making a conscious effort to cut down but it's hard to judge how much the need as the demolish food so quickly (and the fish have got their begging routine down to a fine art!!)

 

[Colin_T]

Also I think I over feed a bit, making a conscious effort to cut down but it's hard to judge how much the need as the demolish food so quickly (and the fish have got their begging routine down to a fine art!!)

LOL. your fish have you wrapped around their pectoral fin

I had fish tanks in the lounge room and my fish use to wait for my bedroom door to open then swim over to the corner closest to the door. Then they would follow me as I walked past the tanks into the kitchen. They didn't do this for anyone else. When they got really hungry and I hadn't fed them, they would splash water through the gap in the coverglass to get my attention