My setup.

[Vannpytt]

I'd like to run some ideas by you as I'm starting a 190G (720L) tank with 80G (300L ish) sump. I'm going to make the scrubber in acrylics with overflow feeding through 50mm PVC. Should be sufficient flow, havn't measured yet.

I'm planning on running 2x 18W 90cm tubes full spectrum 3000k on each side with a W:85cm H:40cm. I will have 4 surfaces and 4 light tubes. In total, the surface will be 85cm*40cm*4= total 1,36 m^2. The lighttubes will be placed 5cm away from scrubber surface with a thin acrylic glass to protect from corrosion and moisture. Would this work?

| = scrubber surface
L = light tubes
R = possible reflector
O = drain to sump

(from top)
|L||L|
|L||L|
|L||L|
|L||L|

(from side, obviously the whole side coverd in reflector material)
||||||||||||||||
LLLLLLLLLLLLLLLL
||||||||||||||||
LLLLLLLLLLLLLLLL
||||||||||||||||
---------------------O

(from front)
R|R||R|R
R|L||L|R
R|R||R|R
R|L||L|R
R|R||R|R
O---------O

Best regards

Henrik

[SantaMonica]

Your light power is too little, and your screens are too large.

18W tubes? Seems like a very low power bulb for 36 inches long. You should be using T8's... the kind in overhead lighting. Dirt cheap, and 30 watts for 36 inches long.

But back to your design... it's way underpowered. You are proposing 4 bulbs of 18 watts each = 72 watts for 270 gal. And worse, the screen will be 40cm (15 inches) high, with only two bulbs per side; this is not enough bulb coverage (much of the screen will be too far away from the bulbs).

Start with your gallons... let's assume that you will have living stuff in your sump. So when you count the sump, you have 270 gal. So for high filtering you need 270 total watts. For medium filtering you need 135 watts.

When using T5's or T8's, you want a bulb every 10 cm or so max, preferable closer. So you want 4 bulbs per side, not 2. This will give you 8 bulbs at 30 watts each = 240 watts. Perfect.

However I think your screens are too big. 270 gal needs 270 square inches (1688 square cm) with light on both sides. Divided by 2 screens, each screen needs to be 135 square inches (844 square cm), with light on both sides (or two sides separated, like yours). 135 square inches can be 10 X 14 inches (25 X 36 cm), which would fit into a sump. Or you could make it long and narrow, which is better: Best performance (although harder to build) for you would be two screens that are each 33 inches (85cm) like you planned, but only 5 inches (13 cm) tall. This is the same height as my acrylic design. This would require 33 X 2 X 35gph = 2310 gph (8778 lph) flow for both screens, which processes a lot more water than a taller design. Also it fits the bulb length perfectly; You still put 4 per side, but you stick them together with almost no space between them.

[Vannpytt]

Yeah, I already assumed that part, and figured it out last night. (T5/8's are not cheap in Norway however) Could you advice where to get such a light setup online? No one wants to ship int.

Second, the flow is comming from overflow drain, 2x50mm. This would not be sufficient to feed 8,7k l/h. More like 6k l/h. I'm not going to have anything living in the sump though, so I'm going for something along the lines of this:

2x W:50cm H: 20cm = 1000cm^2 (screen + light for each drain)
3x T5 30watts on each side (6x in total) = 180 Watts
2x 700 US gallons = 2 650 liter /hour

Better?

[SantaMonica]

Well if you are going to use T5's (it looks like 24" T5's)... they HO ones put out 24 watts, not 30. So I'd use 8 instead of 6. Any local lighting website or store will have these bulbs. Very common.

For the drain:

Screen Width-----Gallons Per Hour (GPH)

1" 35
2" 70
3" 105
4" 140
5" 175
6" 210
7" 245
8" 280
9" 315
10" 350
11" 385
12" 420
13" 455
14" 490
15" 525
16" 560
17" 595
18" 630
19" 665
20" 700


If you are doing an overflow feed, the overflow will determine how much flow you have to work with. You have to start from there, and size your screen accordingly. The maximum flow you'll get to the screen will be what's going through your overflow now. This is easy to figure out by counting how many seconds it takes your overflow to fill a one-gallon jug:

60 seconds = 60 gph
30 seconds = 120 gph
15 seconds = 240 gph
10 seconds = 360 gph
8 seconds = 450 gph
5 seconds = 720 gph


Take this gph number that you end up with, and divide by 35, to get the number of inches wide the screen should be. For example, if your overflow was 240 gph, then divide this by 35 to get 6.8 (or just say 7) inches. So your screen should be 7 inches wide.

When finished, this is how you want your flow to look:

[Vannpytt]

I've been reading ShanGo's fiberglass scrubber and found parts for it.

Going to run a long scrubber with 2 screens. Flow is not calculateed, but is more than enought. Total growth surface each side of the screen is 35cm*40cm=0,14 m2 (0,28m2)*2 scrubbers. Is it pointless to have a scrubber this overdimensioned? The point is to have 1 running while the other screen is cleaned. Total wattage is 18w*6 for each screen=108w, 54w on each side. (216w for both screens) Do I need anything else? Total water volume will be around 700L in DT and 250L in Sump. Planning a DSB in the scrubber with live rock or SeaChem matrix http://www.seachem.com/Products/product ... atrix.html

Each screen (2 sided):
35cm wide * 40cm deep plastic canvas lit by 3x18w PL-L on each side.

L=18w
M=Mesh
|=Acrylic

[code]


| | M | | M | |
| L | M | L | M | L |
| | M | | M | |
| L | M | | M | L |
| | M | | M | |
| L | M | L | M | L |
| | M | | M | |


[/code]

[SantaMonica]

I think you forgot an "L" in your diagram. So, assuming the middle has three "L" instead of two, you would have a total of nine bulbs.

Your total volume is about 240 gal, since you will be having living things in your sump. So basic specs should be:

240 total square inches, lit on both sides
240 total watts for high filtering
120 total watts for medium filtering

Your total screen area is 432
Your total wattage is 162 (not 216)

Your setup would work, but since the bulbs are such tiny spots of light on such big screens (no part of the screen should be more that 4 inches (10cm) from a bulb), there would be a lot of vertical screen not being used. Horizontally is ok, since you have three bulbs across it. But vertically you have one bulb across 15 inches (38cm), so basically the top and bottom of the screens would not be used. So it would be better to cut the height in half. If, however, you need that height so that the screen will touch the water in the sump, then cut the width in half, and arrange the bulbs vertically so that all parts of the screen are within 10cm. There is no need having screen that is not within 10cm of a bulb; it will barely grow, and will just evaporate more.

[Vannpytt]

no idea what i was on. The bulbs should be 24w. I could also use the 36w bulbs.

Assuming I use the 24w and stack another 1 on each side to get them all in good range (total 4|4|4 =12 bulbs)=288w on the 2 screens.

Would it be any point to get the 36w instead of the 24w? Cost wise it's not alot of money.

[SantaMonica]

24 is better, although, it's always better to use more smaller bulbs. This spreads the light and keeps from cooking small spots. Bigger bulbs do put out more light, but you can't use it all because it cooks the spot. So you have to tone it down, but then the outside of those spots don't get enough. That's why T5HO linear bulbs are best; constant light from one end to the other.

So, the more you can divide up the wattage into more smaller bulbs, the better.

[Vannpytt]

T5HO would be my first choice, but believe it or not, we don't have alot of these things available for less than a fortune in Norway.

What would you recomend? I can use up to 75cm wide fixtures. Depth doesn't really matter. It's 230V up here.

[SantaMonica]

Wider the better.