Do I have a lighting problem?

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Gruntle

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Hi all,

I have a healthy population of Blue Stricta in my 130l tank (which I purchased new, so it comes with the original lighting setup). The plants are absolutely thriving, I do absolutely nothing in the way of plant care. Here's a sample:
Stricta Healthy.jpg

During regular maintenance, I have removed a couple of the plants (roots and all) and put them into my 200l (which I got second hand and I think the lighting is a domestic fluorescent light that just rests on the top of the tank). Despite growing new roots and new leaves, the poor things are not looking so hot:
Unhealthy.jpg

Again I do absolutely nothing plant-specific in this tank.

Is the light the wrong sort for healthy plant growth? Should I invest in a proper light tube (it's a standard 4' flouro fitting, and I believe I can get a tube from my LFS)? If so, what should I be looking to buy?

Or is there some nutrient the plants need that the tank is not supplying (should I look at fertiliser)?

Thanks for reading.
 
Perhaps both food and more light. Like fish, plants need food too. Some aquariums can provide this indirectly with fish food and fish waste, but generally some sort of supplemental nutrients (fertilizer) are required...especially for any rooted plants as our substrates are most often inert, not having plant useable nutrients.
Most of the lighting that comes with aquariums is fine for viewing fish but lacks the intensity (now measured as PAR) that plants require. There are some rare exceptions. I do not know if simply replacing a florescent bulb in your current fixture will be enough even to satisfy low light plants. If you try the bulb replacement, you need a daylight 6500k light at the very least. If you decide on a replacement, consider an LED as these represent the future of lighting (both home and for planted aquariums).
A year and a half or so ago I decided to buy a light for my 60g that would support plants (low tech). I bought the 48" Finnex Planted + 24/7 LED fixture (along with a glass canopy to replace my stock florescent tubes). I am very happy with the light. The plants do well and the surrealism that the 24/7 feature provides is awesome (dawn/midday/dusk/moonlight cycle). Now I did put it on a timer so the fish have a period of total darkness and I often boost it to max for more midday 'sun' as my tank is 24" deep. (The new SE model automatically shuts down between 1am and 5am and emits more red during the midday period which I believe they discovered promotes better growth.)
Note that I'm not affiliated with Finnex in any way AND there are many high quality lights on the market that support plants very well.
 
I have no experience with LED or the Finnex AbbeysDad referenced so I leave that tohim, but I do agree with the first part of his post. Each aquarium can be quite different, surprisingly so perhaps. I have 8 tanks in my fish room, all having live plants, many of them are the same species in more than one tank. The lighting is roughly the same, T8 fluorescent tube over the larger tanks and CFL bulbs over the two smaller tanks; all are 6500K. Duration is the same. Fish load is fairly close in each tank. Same fertilizer is added, same relative amount and same frequency. Yet a plant species may thrive like a weed in one tank and struggle in another.

I would first look to the light over the 200 liter (the second photo). What are the tank dimensions, and the tube length? And T8 or T5? A new tube may be all you need, but this data will help us decide. And, tubes do weaken in the intensity long before they stop lighting, usually in about 12 months, and must be replaced.

A nutrient supplement might help too; it doesn't seem needed in the other tank, so I would look first to the light here.

Light intensity drives photosynthesis; and spectrum is important because red and blue (primarily red) are the light colours that do this. Duration also factors in, provided the intensity and spectrum are suited to the plant species and number to begin with. Some plants are fast growing (example, stem plants) are thus need more light intensity. Nutrients have to be sufficient to balance the light.

Byron.
 
Turns out the old tube was a T8 but I haven't changed it since I got the tank second hand (and I have no idea how old it is). I'll report back on how the plants go over the next few weeks.

For reference, the tank is a 48" x 14" x 18" so it's not quite 200l but that's how I think of it. I want a 48x15x24 eventually, but the good lady wife reckons I should spend my hard earned money on our children instead.
 
Turns out the old tube was a T8 but I haven't changed it since I got the tank second hand (and I have no idea how old it is). I'll report back on how the plants go over the next few weeks.

For reference, the tank is a 48" x 14" x 18" so it's not quite 200l but that's how I think of it. I want a 48x15x24 eventually, but the good lady wife reckons I should spend my hard earned money on our children instead.

A single T8 tube over a 48-inch length tank is low light. T8 tubes wear out in about 12 months and need to be replaced; they will still light but the intensity is so low they will be useless. You will need very good quality tubes over this tank, the others are less intense light and work with two tubes. With one about the only tube that will grow plants is a Life-Glo.
 
The tube I got was a Power-Glo. I'm hoping for the best, but it might come down to cost (whether to go for a double fluorescent or LED, and how much month is left at the end of the money).
 
The tube I got was a Power-Glo. I'm hoping for the best, but it might come down to cost (whether to go for a double fluorescent or LED, and how much month is left at the end of the money).

The Power-Glo is the most intense light tube in the Hagen "Glo" series (in T8 anyway) and I have used it. It is high in red and blue, which is why it gives a purplish hue; some people like this, others (like me) do not. But the more important thing is that green is missing and this has been shown to improve plant response. Which is why the Life-Glo remains the single best tube as it is high in red, blue and green for a true colour rendition.

If you have an existing fixture with the single T8 tube, you might be able to get a dual-tube shop light and install this in the fixture. I have replaced the tubes in most of my fixtures with inexpensive T8 shop lights (dual tubes) for a few dollars. In the 4-foot length you can also use the inexpensive T8 tubes like Phillips or Sylvania, in 6500K or a mix of 5000K and 6500K. I've been using these over my 4-foot and 5-foot tanks for 20 years.
 
A quick update. I replaced the tube on Saturday afternoon, it is now Thursday morning. The original photo of the plant compared to this morning (3 days with the new tube):
Unhealthy.jpg 5922.jpg

Looks like a fair amount of green coming back into the leaves already.

Meanwhile, the negotiations have started in the house on whether to shell out for a LED setup (which will cost around $100 online, compared to $30 for the Power-Glo tube). If I do win the argument, is there anything I should make sure the light has (e.g. full spectrum)?
 
A quick update. I replaced the tube on Saturday afternoon, it is now Thursday morning. The original photo of the plant compared to this morning (3 days with the new tube):
View attachment 85474 View attachment 85475

Looks like a fair amount of green coming back into the leaves already.

Meanwhile, the negotiations have started in the house on whether to shell out for a LED setup (which will cost around $100 online, compared to $30 for the Power-Glo tube). If I do win the argument, is there anything I should make sure the light has (e.g. full spectrum)?

Assuming you are in Australia, I don't know what relationship $100 has to North America, but this seems like not much for good LED, so I would check that it is worth it. Abbeysdad has a good LED planted tank light. Most LED is not good plant light, as it lacks the red in the white mix.

"Full spectrum" is a bit misleading. I have seen tubes with very different spectrum so labeled. Yoou want red and blue to drive photosynthesis, and green for good colour rendition. Usually light between 5000K and 6500K provides this, or with a CRI close to 100.
 
By the way, $100 Aus is around $80 US at the moment. The LFS has a unit at around $300 but I'm not totally happy with the look of it (looks like about 2' of lights and 2' of extension bars).
 

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