LED Low Light

[Rodgie]

Hi aquascapers!

I'll be setting up a tank soon. And the light the tank comes with is 37LED lights. It says that it has 821Lumens.

Now, my set up will be a low tech and my plants will be slow growers only.

To achieve a low light with this particular LED I'll have. Is 4 hours photoperiod safe enough to keep it in the low range of light? I mean that's how much I'll set it in the very beginning anyway, but just in the future how far can I increase it and keep it still safe to avoid algae?

Thank you,
Rodgie

 

[Bart Hazes]

Without knowing the size and depth of your tank that could either be a bright or very dim light. Unless the tank is very expensive I expect it won't be a very bright light to start with and 4 hour photoperiod seems awfully short to me. One option is to pick up a decent amount of floating plants from a fellow aquarist for (next to) nothing. That will help compete with the algae for nutrients and reduce the light intensity that reaches the substrate. I normally start my tanks at 10-12 hrs photoperiod and they end up with about 12-13hrs of light per day. But there is a wide range that is used in the hobby and no one way that is 'correct'. I like about 12 hrs because it is somewhat close to daylength in the tropics and long enough that I can observe the tanks before and after work.

 

[Rodgie]

Hi Bart,

The height of the tank is 11.6 inches. And there's about another inch distance from the light to the bottom of the tank. So I guess it's safe to say that there's about almost 12 inches space from light to the gravel(after it's set up).

I think if I start this tank (with the type of light) for 10 hours. It'll face some algae problems soon because I won't be dosing any Co2 at all. I wanna keep it low tech. So maybe I'll start with 5 hours if 4 hours is too short. Then I'll work my way up to 8 hours slowly.

I've seen some reviews about the product, and many said it's good for low tech set up. I just want to make sure I don't overwhelm the plants in the early stage of the set up. And gain plant mass than algae pains.

Kind Regards,
Rodgie

 

[zozo]

If you have a dimmer to play with you can go as long in periode as you want, if a natural pond can stay relatively algae free with 18 hours of daylight/sunlight. It shouldn't be a problem for an artificialy lit indoor tank. It's all about intensity and the plants compensation point in how far you can go with intensity verus periode. All my low tech tanks have slow growers and a 12 hour light periode.. And i also tried 18 hour artificial light periode with a test setup. Not a problem at all if the plant growth vs intensity allows you to..

Also got an open top low tech standing under an opaque transparant roof window. From may to september i can switch off the artificial lights and keep the tank running on daylight. I have no saying in period nor intensity. Periode goes to 18 hours mid summer. This year we had a rather early summer with very sunny clear days and a lot of intensity. And it started growing green spot algae on the anubias. Had to start dosing Easy carbo to keep the ballance it worked realy well.. The previous year it was much more cloudy with less clear days and didn't have the GSA issue it ran the complete year easy carbo free. Now it's november, days are much shorter and way less intense, artificial lights are on again on 12 hours and havent dosed any easy carbo for 2 months.and still running well no GSA.

I use a multi channel programmable dimmer on this tank and for the moment have 4 x 700 lumen cob led light sources.. slowly start the day with 1 source, 1 hour later the 2nd kicks in, again 1 hours later the 3th, 2 hours later the 4th.. That's mid day all sources.. Than it goes down again the same way, all within 12 hours periode.. I use to have 5 x 700 lumen sources but one burned out a while ago. I leave with the 4 which is sufficient. No idea what i have in par at the substrate bellow the filtering floaters.. The sources hang 40cm above the tank, there definitively will be some loss. I don't care, the plants tell me it's ok.

It's this one At the time of the pic taken, early morning, it had 2 light sources running.. The only fast growers in there are the floaters..

Oh Ps. I was wrong, i checked the controller it has 14 hours periode..

 

[Edvet]

It says that it has 821Lumens.

Sadly this has no meaning about the actual strength . (only PAR is useful, sadly few manufacturers give this)
Floaters are indeed a good way to limit light if there is no other way, increasing height over the tank is another way.