Plants survive, not thrive.

Hello,

Suffice it to say that I have never, ever had a planted tank thrive (beyond once having duckweed...). I've never killed off plants, but they always seem to just "exist". I can grow almost anything in soil, but I'm really struggling here... Looking for some general advice - and I will make note that while there are certain things I can do (like change my substrate), they may not be practical for me. Still any advice is welcome because I'd love to learn how I can do better now or in the future.

I've picked some plants up on clearance and don't remember the names but currently I have about 5 Sword Plants (variations, one is an Amazon Sword), some Java Fern, and two other types.

Water stats of my testing last week:
pH: 7.4
Ammonia/Nitrite: 0
Nitrate: 10
Hardness: Pretty soft as I mix RO water with a smidge of our tap water (which is EXCEPTIONALLY HARD).

Tank Light:
20 inch LED: 72 LEDs, with 60 being white and 12 being blue. Broadcasts at 640 lumens (11 watt)
--->https://www.amazon.com/gp/product/B00X84LVH6/?tag=ff0d01-20

Tank Size: 20g, with pea sized gravel substrate and driftwood

Fertilizing: I use Seachem's Flourish 2x weekly and Seachem's Phytonutrient daily.

As I said, plants seems to "exist", but no real growth. What am I doing wrong or could I be doing better?

Pictures of the plants?

Some plants are true aquatics and do well underwater, other plants are marsh plants and don't do well underwater.

The substrate is probably a bit course for them but that is not too much of an issue for aquatic plants.

Lack of light is a possible cause. Most plants need around 12 hours of light per day and you want reasonably bright light. Try adding another light unit or increasing the photoperiod (depending on how long the light is currently on for).

Nutrients are essential if you want plants to grow. You add some and that is probably not the issue.

Thanks for the quick reply, Colin.

I can get some pics up tomorrow, but all plants are fully aquatic. I have seen semi-aquatic at the store but honestly, that is not something I'm interested in.

I have a timer set for the aquarium - it gets roughly 14 hrs of light per day. I've heard that this is acceptable due to refraction (as in, let gets diluted when it hits the water). I'm totally willing to adjust the amount if others advise it.

I don't know much about aquarium lights, but I've heard good things about LEDs (and I use them to grow plants hydroponically)so I thought what I had was a good, economical choice. The wattage rule doesn't helpmeet much because LEDS pull so much less.

Last night I posted pics of all my tanks and they are doing better than surviving. I can't claim these are show plants as there are bits of algae on them and the odd yellow or brown blotch. All have LED lights and my light period is between 7 and 9 hours per day - different for each tank. All have floating plants which reduce the amount of light. To get the light right I start at 6 hours a day and increase it by 1/2 an hour every couple of days. When I see algae on the glass I turn it back to the previous setting.

I use root tabs (Seachem when I can get them) and replenish every 2-3 months. Flourish complete once a week after water change - do it a day later if you use de-chlorinator. Half strength in 2 of the tanks and full strength in the other. 2 of the tanks have 0 hardness as they use pure RO. If plants don't work for me I chuck them out and try something else. I have also found that it is worth buying quality plants which usually means the branded ones. My frogbit is a good example of this, I tried to grow it several times using plants from ebay or amazon and always failed. Then I bought a pot of Tropica 1-2-3 grow and its all over my 3 tanks now.

Part of the problem may be the light. From what I have read, plants need some red in the spectrum to do well but yours have white and blue. Is there a K rating anywhere on the light itself or the packaging/leaflet? Plants do best at around 6500 K.

I switched from Seachem Flourish Excel to Seachem Flourish Comprehensive and I also use Seachem Flourish Iron.

Since I switched from the Excel, my plants have grown much better, in fact I now have to prune them every 2 weeks to stop them taking over.

My tank is 240litre and is quite deep. I use a Fluval Aquasky 2.0 33watt light that I have on at full intensity for 7 hours a day plus a slow increase and slow decrease morning and evening.

Thanks guys.
According to the website it’s 7000k. But yes, no red light.

What should I be looking for regarding light?

7000 K should be OK. The white LEDs may have a red component.

Can you turn the blue LEDs off and have just the white ones on? Some light strips let you do this but most don't.

Light is likely the main issue here. This needs explaining as it is important you (the aquarist) understand the whole picture.

Light intensity drives photosynthesis, and spectrum is important in this. The duration is not the issue, it can be as low as five or six hours each 24-hour period, or more but not much over 12 hours as the fish must have a period of several continuous hours of total darkness. Red and blue light drives photosynthesis, but of these red is far more significant and thus has to be high in the mix. Adding green to this combination does improve plant growth according to scientifically controlled tests. Each species of plant has specific requirements respecting the light intensity to drive photosynthesis; high light plants need stronger light, while low light plants (just like shade plants in the garden) require less light intensity. Duration does not and cannot make up for deficiencies in intensity.

The intensity may be OK here, but the red does seem to be lacking. The white light on its own might be adequate in this regard. Additional blue light is only likely to cause trouble for plants and may increase algae problems. Spectrum can be measured as CRI (colour rendering index) and Kelvin. A high CRI (close to 100) or a Kelvin around 5000-6500K is best. My tanks all run with 6500K tubes for the single-tube tanks, and a 6500K and 5500K tube for the two that have dual tubes.

Nutrient must balance the light intensity and duration, and here duration does make a difference if the light is on longer than the nutrients balance it. You mention sword plants, and I can assure you that these will always be in better shape with substrate tab fertilizer. The substrate material is irrelevant. My tanks are all play sand, and prior to the change they were fine gravel for years. I did try one so-called plant substrate and it was a total waste of money.

My advice taking into account the existing light is to disconnect the blue lights and go with the white, and for 7 or 8 hours each 24-hour period. Use a timer so it is consisteent, one "daylight" period of 7 or 8 hours, and have this period when you are normally home to enjoy the tank. Use the liquid Flourish Comprehensive Supplement you have, once a week in the amount indicated on the label, and dose on the day following the water change. [I have never heard of Seachem's Phytonutrient and cannot find it on their site...what is this?] I would also get a package of their Flourish Tabs and place one close to the crown of each of the sword plants; replace these in 3 months. A 20g tank is very small for sword plants, but if they grow, who cares.

It takes a few weeks for changes to become noticeable. A photo of the tank would help, so we can see the state of the plants now. They may be good to another set of eyes, lol. Below is one or two of my tanks that follow what I suggest above.

I've just checked the light link again, and the only options are blue & white or just blue. I replaced a clip on light which had these options, the new light has blue, white and red LEDs with the only options being on and off.

kribensis12 said:

Hello,

Suffice it to say that I have never, ever had a planted tank thrive (beyond once having duckweed...). I've never killed off plants, but they always seem to just "exist". I can grow almost anything in soil, but I'm really struggling here... Looking for some general advice - and I will make note that while there are certain things I can do (like change my substrate), they may not be practical for me. Still any advice is welcome because I'd love to learn how I can do better now or in the future.

I've picked some plants up on clearance and don't remember the names but currently I have about 5 Sword Plants (variations, one is an Amazon Sword), some Java Fern, and two other types.

Water stats of my testing last week:
pH: 7.4
Ammonia/Nitrite: 0
Nitrate: 10
Hardness: Pretty soft as I mix RO water with a smidge of our tap water (which is EXCEPTIONALLY HARD).

Tank Light:
20 inch LED: 72 LEDs, with 60 being white and 12 being blue. Broadcasts at 640 lumens (11 watt)
--->https://www.amazon.com/gp/product/B00X84LVH6/?tag=ff0d01-20

Tank Size: 20g, with pea sized gravel substrate and driftwood

Fertilizing: I use Seachem's Flourish 2x weekly and Seachem's Phytonutrient daily.

As I said, plants seems to "exist", but no real growth. What am I doing wrong or could I be doing better?

Click to expand...

You need more Lumens. 650 Lumens at 20 gallons works out to about 8.5 lumen/ liter.
Low light plants need around 20-30 lumens/ liter. A 20 gallon is about 75 liters 20×75=1500.
So your short almost 1000 lumens. Provide the correct light then go from there. Without proper lighting all the fertilizer in the world wont do much because the plants dont have enough light to utilize them in photosynthesis.

I appreciate the feedback everyone!

So to summarize:

1. I should replace my LED strip with something that also has red in it
2. I should also increase the amount of lumens to around 1500.
3. Once established, I should adjust the lighting to more naturally reflect lighting.
a. Again, this has been confusing for me as my AeroGarden (hydroponic) has lights running for 14-16 hours a day with phenomenal results.

Am I missing anything here? Hoping to get pictures tomorrow - things have been busy today!

Here we are:

** The Sword tucked in the driftwood is a very recent addition which is why it looks so great, along with the taller leafed plant (whose species I CANNOT remember). Everything else has been there at least 4 months with the worst looking sword being 3 years old.

I've tried sifting through amazon for a quality, affordable LED and the choices are inundating. Any suggestions?

kribensis12 said:

Again, this has been confusing for me as my AeroGarden (hydroponic) has lights running for 14-16 hours a day with phenomenal results.

Click to expand...

Hydroponic terrestrial plants is a very different thing from aquatic plants when it comes to light. In an aquarium, there are nutrients in the water and the substrate, and algae is capable of using these under any light. When you have plants, you need to provide sufficient light intensity but it must be balanced with the available nutrients according to the requirements of the plants (this involves species as they are not the same in requirements, and numbers). As soon as some necessary factor (light or a nutrient) is not sufficient, photosynthesis will slow and that is when algae has the advantage because it is not as fussy as higher plants.

The duration of the light factors in once you have the intensity and spectrum settled for the plants. CO2 (carbon) is generally the first nutrient to be used up, and this is where the duration of the light enters the balance. I tend to start off with "x" hours of tank light, then adjust it according to problem algae. Over a couple of years I got the lighting duration down to 8 hours and had no problem algae. I noticed that in the summer, problem algae (black brush/beard in my case) began to increase. It finally dawned on me that the additional daylight entering the room in summer, due to longer days and brighter sunlight, was behind it, and that proved to be correct. I added heavy drapes (blackout type) and kept them closed in the summer, and no more algae problems after that. The point is that light is the governing factor, but it needs to be balanced by the required nutrients, and it is easy to upset this balance. The same thing can occur if the tank lighting is not replaced properly; fluorescent tubes for example weaken in intensity as they burn, and when they weaken to the point the intensity is no longer sufficient to drive photosynthesis, algae again appears.

kribensis12 said:

Here we are:

** The Sword tucked in the driftwood is a very recent addition which is why it looks so great, along with the taller leafed plant (whose species I CANNOT remember). Everything else has been there at least 4 months with the worst looking sword being 3 years old.

I've tried sifting through amazon for a quality, affordable LED and the choices are inundating. Any suggestions?

Click to expand...

Ive used LED bulbs in a bunch of shop light goose neck fixtures problem with LED globe bulbs is its tough to find ones above 5000K
Cree lighting makes some good bulbs with 90+ CRI rating. Lumens are the determining factor. Like i said earlier, around 20-30 lumens/ liter is recommended for low light to medium light plants.
One could also use CFL bulbs in a gooseneck. Light fixture as well. GE i think it is makes a spiral CFL 6500K bulb thats 20 watts and provides 1250 lumens/ bulb. Those bulbs are like 5$ each the light fixtures at walmart, hone depot are like 10 bucks. You buy 2 bulbs and fixtures that would be about 30 bucks for 2500 lumens.2500 lumens might be over kill in which case you could go down to 15 watt bulb which provide about 850 lumens two bulbs would give you 1700 lumens.