advise on led light - one sided waterfall edition

[Leonhardt]

Hi

I am new at ATS building but I like the princippel behind it and have build one for our reeftank.

It is two canvas 21x29 cm each
With a 1400 l/h pump and a small led refugium algae scrubber lamp from www.aquastyleonline.com -refugium lamp

Our tank is 340 liter and it is the goal that the scrubber should be able to replace the skimmer completely and to add more pods to the tank.

I have talked with several people regarding led light and now I thought I would seek som advice here.

How many led watt should I get and what color mix are most optimal?
Can I start with the one I got or is this hopeless.

BR Michala

[SantaMonica]

Welcome from Denmark,

Did you get the flexible one?

[Leonhardt]

I got the only lamp they had under refugium lamp.

It is 5w led but they said it was comparable to 10w.

[SantaMonica]

Using the size guidelines here:
http://algaescrubber.net/forums/showthread.php?1419-New-sizing-guidelines

You have 21 cm X 29 cm = 609 square cm. Each 75 square cm is good for 1 cube a day if you have 12 total real CFL watts (6 watts on each side) = 6 total LED watts (3 watts on each side) for each 75 square cm.

However you have only 5 total watts on one side of one of the screen. So no, it's not going to work.

So start by asking yourself how much you will be feeding, and, are the rocks soaked with phosphate.

[Leonhardt]

I have tested the phosphate to 0.01 and I have two screens that are 21x29 each and there should only be light on one side. They are light by the same lamp (I have removed the lense since the picture was taken)
I only feed max 1/2 tespoon a day with pillets and give them 2 cube once a week(artemia and cyclop)
And then I feed with a pince of reef pearls and 2 ml sango kai amino.

I will try to modify my lamp to 12-20 led watt if it is possibel.

Thanks for the advise.

[SantaMonica]

How many kilo's of rocks, and were the rocks from a problem aquarium before?

[Leonhardt]

Approx. 40. Kg
10 dead
15 from a well funktionate aqurium
15 from an aqurium with some algae.

[SantaMonica]

Ok so 15 kilo = 33 pounds of problem rock (phosphate soaked). Each 50 pounds of problem rock adds 1 cube a day to the feeding, so yours is adding about 0.7 cubes a day. Not a lot. So total is probably less than 2 cubes a day.

You only need 2 X 12 = 24 square inches = 150 square cm of screen. This needs at least 24 total CFL real watts (12 on each side), or half that in LED watts. Since yours is 600 square cm for 2 screens, can you remove one screen? This will give you 300 square cm.

Then you will need at least 24 watts of LED (12 on each side). Can you put LED on both sides?

[Leonhardt]

No only on one side. Thats why I made it twice as big and also so it would be possible to clean seperatly to avoid high increasement in phosphate and nitrate levels when cleaning.

[SantaMonica]

Ok then do this: Remove one screen and seal the water slot. Then cut the remaining screen in half (up and down) so that you can clean one half at a time.

[Leonhardt]

Okay but is one screen enough if it is only light on one side?

[SantaMonica]

It still is 300 square cm, which is twice the 150 that you need. So yes.