24inch Finnex HLC Planted + LED Fixture

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kribensis12

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I just purchased a new LED light and I definitely have very little aquatic plant experience (terrestrial, I can grow anything. Aquatic - meh).

This light is about 8000K and is programmable. The previous light on the tank was one white & blue LEDs and definitely was not doing the job (for obvious reasons). So, here is the conundrum:

It's programmable, but only in stages of 3 hours. My current programming is this - thoughts?
7-9, white & blue, 1/2 brightness (simulate morning), 9-12 Max Brightness, 12-3 darkness, 3-9pm Max Brightness, 9-12 - blue light only 1/2 brightness, darkness until 7.

Link: https://www.amazon.com/dp/B07S9H64L1/?tag=ff0d01-20

I'm trying to balance being able to actually see my fish (depending on my schedule) and making sure the plants receive enough light without exposure.

Thoughts?

Because I'm sure it'll be asked:

Tank size: 20gs
Plants: Swords predominantly (a few other whose names I can't remember) - all require strong lighting
Fert: Daily flourish advance (phytonutrient) and weekly Flourish liquid. I have root tabs too.
Water:
Nitrite, Ammonia: 0 ppm
Nitrate: 10 ppm
pH: 7.4
kH and gH: I don't have a tester for this, but I mix my own R/O water so it's safe to assume it's very soft.
 
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It looks like a super good light.

The fact that it has good reviews, a remote, and multiple colors makes it all worth while.

Are you saying for the different brightnesses, it can only be programmed for 3 hours?
 
Thanks!

You have to program it by sets of 3 hours. It has a 24 hr/7 day a week auto setting where it mimic's sunrise through sunset, but online reviews of that feature are not very good. Many aquarists say that it does not provide enough high output light using that setting.
 
That is cool. I’ve wanted a light that could do that, but I never could afford a decent one. :(
 
I am only responding on the schedule aspect. The schedule mentioned in post #1 is not good for the fish, or the plants, but plants can tolerate it better than the fish. The reason is the circadian rhythm that all fish (all animals for that matter) have, and plants have similar.

The "daylight" which is the brightest light must be one continuous period in each 24 hour period. It cannot be separated. Same for the "night" which must be a continuous period of total and complete darkness, with no external light (daylight, ambient room light) but total blackness (or as close as one can get, there is often some ambient light at night entering the room). This is very critical to fish.

The "dawn" and "dusk" periods between these two blocks of daylight and night can be any length.

The "daylight" when the light is brightest is the period when the plants will photosynthesize, and it can be as little as six hours. This period is usually determined by algae; if the plants have sufficient light intenisty to drive photosynthesis and all required nutrients are available, they will do it. As soon as something becomes insufficient to balance, photosynthesis slows, and may even cease depending what the limiting factor is, and then algae has the advantage. Some systems might be fine with 8 hour, some 10, some even 12 hours of "daylight." But if everything is not balanced, algae will have an advantage the longer the light (daylight) remains on.

The "night" darkness is pretty obvious, and it needs to be several hours during each 24 hour period, and in a block as I said. This is when fish and plants rest, and their metabolism is greatly reduced. It is critical "sleep" time, and shold be at least five or six hourts, but a few more will not harm things.

The dawn and dusk periods need to be controlled; if the white and blue light is on during this period, it will likely be insufficient to drive photosynthesis, but it can really encourage algae. Without the red light, photosynthesis cannot occur, but algae doesn't care.
 
I am only responding on the schedule aspect. The schedule mentioned in post #1 is not good for the fish, or the plants, but plants can tolerate it better than the fish. The reason is the circadian rhythm that all fish (all animals for that matter) have, and plants have similar.

The "daylight" which is the brightest light must be one continuous period in each 24 hour period. It cannot be separated. Same for the "night" which must be a continuous period of total and complete darkness, with no external light (daylight, ambient room light) but total blackness (or as close as one can get, there is often some ambient light at night entering the room). This is very critical to fish.

The "dawn" and "dusk" periods between these two blocks of daylight and night can be any length.

The "daylight" when the light is brightest is the period when the plants will photosynthesize, and it can be as little as six hours. This period is usually determined by algae; if the plants have sufficient light intenisty to drive photosynthesis and all required nutrients are available, they will do it. As soon as something becomes insufficient to balance, photosynthesis slows, and may even cease depending what the limiting factor is, and then algae has the advantage. Some systems might be fine with 8 hour, some 10, some even 12 hours of "daylight." But if everything is not balanced, algae will have an advantage the longer the light (daylight) remains on.

The "night" darkness is pretty obvious, and it needs to be several hours during each 24 hour period, and in a block as I said. This is when fish and plants rest, and their metabolism is greatly reduced. It is critical "sleep" time, and shold be at least five or six hourts, but a few more will not harm things.

The dawn and dusk periods need to be controlled; if the white and blue light is on during this period, it will likely be insufficient to drive photosynthesis, but it can really encourage algae. Without the red light, photosynthesis cannot occur, but algae doesn't care.


Thanks Brian. I thought in a previous thread that you suggested that you could go light-to dark to light. I must have misread.

So given the specifics of this particular light, what type of schedule do you think would make the most sense? I did about an hour of research on custom light settings from different planted tank keepers and it seems like everybody and their brother does it differently.
 
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Thanks Brian. I thought in a previous thread that you suggested that you could go light-to dark to light. I must have misread.

So given the specifics of this particular light, what type of schedule do you think would make the most sense? I did about an hour of research on custom light settings from different planted tank keepers and it seems like everybody and their brother does it differently.

Yes they probably do. And few likely understand fish physiology, which is crucial if fish are present. A lot of planted tanks have no fish to worry about.

@AbbeysDad has the Finnex I think, so he can fill you in on how he manages it.

My only caution here was that the "daylight" when the brightest lighting is on for the plants must be one continuous period in each 24 hours, and this daylight period length depends upon the plants and nutrient availability to avoid algae.
 
My only caution here was that the "daylight" when the brightest lighting is on for the plants must be one continuous period in each 24 hours, and this daylight period length depends upon the plants and nutrient availability to avoid algae.
So is it bad in my 5G, 10g, and 29g that I leave the lights on for 14 hours a day? (Mine are not adjustable)
 
So is it bad in my 5G, 10g, and 29g that I leave the lights on for 14 hours a day? (Mine are not adjustable)

No, not necessarily. The main thing is to have the "daylight" which is the brightest tank lighting period on for a continuous period of "x" hours, and then also ensure there is a total black darkness for several hours.

The daylight duration is usually determined by algae. I have my tank lights on for seven hours, and I have no algae issues; if I were to increase this (it was 8 hours, and 10 before that) I would have algae problems.
 
No, not necessarily. The main thing is to have the "daylight" which is the brightest tank lighting period on for a continuous period of "x" hours, and then also ensure there is a total black darkness for several hours.

The daylight duration is usually determined by algae. I have my tank lights on for seven hours, and I have no algae issues; if I were to increase this (it was 8 hours, and 10 before that) I would have algae problems.
But how is it that I keep my lights on for 14 hours each day and have no algae?

Also, another question.

In the mornings, when I get up, I turn my fish tank lights on first, then m room light. Is this bad for my fish? Will it “blind” them? I’m asking because I know when I wake up and there is a bright light, it hurts my eyes.
 
I turn my tank lights on at noon, that way the fish have a sunrise and early morning light that comes in the window. At night my tank lights go off at 9pm and the lamp in the room which is not bright stays on until 10pm so they have a sunset.
 
But how is it that I keep my lights on for 14 hours each day and have no algae?

Each aquarium is biologically different. This is a long period, but back in the 1990's my tanks' lighting was on for 15 hours, from 7 am to 10 pm every day. I did have a bit of black brush algae in one tank, but not bad. But after I moved in 2000 and re-set my tanks I started at 12 hours and worked down to eight before algae no longer increased.

In the mornings, when I get up, I turn my fish tank lights on first, then m room light. Is this bad for my fish? Will it “blind” them? I’m asking because I know when I wake up and there is a bright light, it hurts my eyes.

It depends upon the ambient daylight in the room. Never turn on the aquarium light in a room that is dark, and the same holds for turning the tank light off. In both cases, the room must be in light, whether ambient daylight or artificial lights.

One of the reasons I went down from 8 to 7 hours when I moved last May is because it allows me to use the daylight and not have to hook up another room light. When the tank lights come on at 9 am in the winter (darker) months, there is daylight coming through the window blinds. When the tank lights go off at 4 pm there is still daylight entering the room. When I had the lights come off at 5 pm, it was dark outside (in winter months) and I had a room light on a separate timer that came on a few minutes before the tank lights went off, and remained on for an hour. This provided the fish with a dusk/dawn situation.
 
I have this light on my 55. It's the 4 ft version and It's an awesome light.

I keep the light on for 8 hours on max power on a timer.

I couldn't get the 24 hour cycle to work for my viewing preferences. One day I'll play around with things to take advantage of the settings.
 
I have this light on my 55. It's the 4 ft version and It's an awesome light.

I keep the light on for 8 hours on max power on a timer.

I couldn't get the 24 hour cycle to work for my viewing preferences. One day I'll play around with things to take advantage of the settings.


Thanks!

@AbbeysDad how do you use this light to get the best results?
 

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