Specification of LED light to use for my 4 feet tank

**alvintcs** · 22nd Mar 2016, 00:51

Hi,

Re-scarping my 4 feet tank after 4 years, below is the setup of my tank.
- 4 x 1.5 x 2 (feet)
- Green Element EVO 36 LED lamp x 1
- ANS Planta Soil

Picture of setup: https://www.dropbox.com/s/h4hf3280qs...55.37.jpg?dl=0

My issue is my plants does not seems to grow, and slowly turning yellow, those loose plants that is floating in water grows better in this case. It appears those plants that is nearer to the surface grows better while those at the bottem of the tank are slowly dying. This leads me to think that my current LED light is not powerful enough to penetrate into the surface of the water. If this is the case, then what can I do? change the LED to another model? Any advise from seniors here?

**Realcaster** · 22nd Mar 2016, 01:05

Hi, what was different from your previous setup before the rescape?

**alvintcs** · 22nd Mar 2016, 11:40

hi, everything the same except the lighting which I changed from 4 tubes T5 to existing LED as the former was burnt.

**Realcaster** · 22nd Mar 2016, 12:05

It could be your water depth. I have used similar LED with great success with depth up to 45cm. The newer Evo version have focusing lens that increase depth penetration but not available locally. I ordered 2x 4ft from oversea to cover my 4ft tank which have a height of 50cm. Yours is 60cm height which is even deeper, I would suggest lowering down your water level to 45 cm.

please note, due to the focusing lens of the new EVO model, you may need 2 LED light to cover the whole tank.

**fireblade** · 22nd Mar 2016, 14:43

what plants did you try to grow?
from the photo looks bright enough maybe keep some lower light requirements plant?

**Realcaster** · 22nd Mar 2016, 18:19

Hi

I have found some interesting material with regard to PAR of a 4ft Evo3W under 45cm of water )approximately 17.7inches

The PAR value is 130 at substrate (17" depth) you can grow almost all aquatic plants with Par >80

http://www.plantedtank.net/forums/10...se-arrays.html

Your LED is of similar model and so it should be OK if you lower down your water to 45. Please note LED lights do have a life and its brightness diminished after some time.

May I know how long have you being using this LED?

**Realcaster** · 22nd Mar 2016, 23:30

A correction the par value of 130 is for 2 set sets of 4ft EVO 3W LED light

**alvintcs** · 22nd Mar 2016, 23:55

Hi,

Have been using this light set for 1.5 years.

**alvintcs** · 23rd Mar 2016, 00:19

Thanks for sharing bro!!
From what I see my tank is abit too deep, if I choose not to lower down my water, that would means I have to fall back to T5?

**Realcaster** · 23rd Mar 2016, 00:40

I think it's too early to draw a conclusion, because if you google on the interest, many in US and UK have being successful in using that LED in 2ft depth tank, but they are using the newer model with the focusing lens. I would suggest you plant some plant directly under the LED. If it grows, it could very well mean you need 2 light to cover your whole tank

**alvintcs** · 23rd Mar 2016, 00:52

Refer to https://www.dropbox.com/s/v3avyzfmnf...44.25.jpg?dl=0
As can see from the picture, it is obvious that the part of the stalk which is near the surface are greener than the lower stalk which is further into the water. In fact those further down are brown in colour now.

**alvintcs** · 23rd Mar 2016, 21:43

I think throughout the discussing, we miss out the water temperature, this struck me today when the weather seems exceptionally hot today.
Just measured the temperature of my water, its 31 degrees. I think this temperature is abit too hot for most plants to survive?