Building a new acrylic scrubber

[DesignsOnline]

Seems like a complex attempt for a first scrubber, especially since you don't have anything right now. How about just starting with a simple external one first.

Well I could do, but I dont see what this would acheive other than an increased evaparation rate.
We all know that a scrubber works, and I wouldnt want to run a messy system or one that could risk spraying anywhere...

Plus I want to ensure that the lights and the screen are kept very carefully apart.

It'll work, but the spots in front of each bulb will tend to burn since they are so close to the bulbs. Reduced hours will fix this.

I am planing to use the same photo period as my main lights so I can use the same auto timer system.
This will run about 9 hours of light a day....

[DesignsOnline]

Just to make it clear in case I didnt mention it already, the water will enter the scrubber via the central weir, the return pump from the sump to the main tank above is an Ocean Runner 6500.
So there is a lot of flow, the pipe from the weir to the scrubber is 40mm so it will allow for a lot of fast flow over the scrubber.

The scrubber will be 24inches wide by 15 inches high, and the screen will probably be 23 inches wide by 12 inches high, lit both sides (with around 5000 ltrs per hour flowing down it)
with the 3 x 20w energy saver bulbs each side of the screen hanging about 3 inches from the screen with a clear acrylic barrier between the 2 on both sides. (6 bulbs in total)

Does this sound like a good design and an effective scrubber for the size tank it is on? (Equivilant to a 5 x 2 x 2)

[Floyd R Turbo]

A 23 x 12 screen would be good for a 275 gallon tank. You're running what, a 150 or 180 bowfront? You want 1 watt per gallon of system water, so 6 x 20W CFLs is only 120W, you're going to be running a scrubber screen that is larger than your system with light that is lower than your system. Essentially an oversized, underpowered scrubber.

The first thing I would do would be to verify the flow coming from the DT, not by calculating it, but by actually measuring the flow rate in GPH. Then divide this by 35 GPH/in and get your ideal screen width, and divide this into your tank size to get your ideal screen height. Design around the flow available. If you know, for sure, that you're getting more than 800 GPH from your overflow, then a 20"+ wide screen is no problem.

After you have the screen properly sized, then you pick out and design how you are going to light it, with 1 watt per gallon or 1 watt per square inch of screen dimension.

[DesignsOnline]

Well in that case what about if I were to run 4 x 45w bulbs, 2 at the front and 2 at the back:
here are the bulbs: http://cgi.ebay.co.uk/45w-225w-Dayli...item415b1e52a1

They are 45 watt but are equivillent to 225 watt bulbs!


Or I could run 6 x 30w bulbs (each equivilent to 150w - total equivilent 900w)
http://cgi.ebay.co.uk/30W-BC-DAYLIGH...item1c11e019fe

It wouldnt be under powered with either of these configurations would it...?

[DesignsOnline]

The algae isnt going to know how many watts are being eatien up running the lights, they are just going to "know" how much light or how many lumens are being produced by the bulb.

A 30 watt Low Energy Lightbulb claims to be Equivelant to a 150 watt ordinary bulb.

The 30 watt energy saver bulb produces 1897 Lumens in 2700K Colour
a standard old fashioned 100 watt incandesent light bulb produces 1,700 Lumens

So in reality it is slightly better than equal to a 100 watt bulb. The wattage actually in reality plays no part in the equasion, it is merely used as a guide im sure.

If you were to run 2 identical scrubbers (of the dimentions that I have given for mine) 1 using 6 of the 30 watt energy saver bulbs each producing 1,897 Lumens,
and another using 6 standard old fashioned 100w bulbs each producing 1,700 Lumens

According to the theory on this site as I understand it, the scrubber using the energy saver bulbs would perform 70% worse than the scrubber using the old fashioned 100w bulbs.
The Lumens and the light spectrum or Kelvin rating is a far more important measurement surely?

[Floyd R Turbo]

The higher the wattage, the more problems you get with hotspots. It is better to use more lamps at lower wattage, because they can be closer and the light is more easily diffused with reflectors.

Equivalent wattage simply means the CFL lamp puts out as much lumens as the comparable incandescent lamp wattage. "energy saver" just means it uses less energy for the same light output. Neither of these mean anything when discussing scrubbers. All we care about is actual CFL wattage.

You have your answer in your last post. Lumens is what matter. CFL wattage and lumens usually go hand in hand, the more CFL watts, the more lumens. They are not directly related, so if you want to get really picky about it you can try to look at the lumens, but you're getting in to way too much detail than what is needed.

You need to just focus on CFL wattage (actual) matching the screen dimensions.

[DesignsOnline]

Well I have made a start on the scrubber build today, so will post up the photos as we go along.
The acrylic isnt too bad to cut with a jug saw, but we have broken a could of sheets by not cutting as smoothly as possible

[Floyd R Turbo]

Are you planning a watertight box? If so, you might have a hard time making that work by using a jigsaw to cut the pieces. You would be better off finding an acrylic supplier and giving them dimensions to cut. You need an edge that perfectly straight and flat in order to bond to the adjacent piece. If not, the weld-on won't wick in fully and you'll end up with gaps, and you'll have to add gussets. Or you could flatten and straighten the edges by dragging a razor blade across it after the rough cut.

Cutting acrylic takes practice, because if you cut too slow, it melts. Cut too fast, it cracks. All fabrication, including welding, induces stress into the material which can weaken the bond strength if done improperly. Now our boxes typically don't fill with water 100% so this is less of a concern, and as long as this is over your sump, it's not big deal. If you had the box off to the side of the tank, you would want it built as if it was an aquarium that needed to hold water 100% full and never fail.

[DesignsOnline]

I only took 4 photos, but I cant move them off the phone on to the memory card!
When I plug it in to the computer it reads the card, but wont access the phone, I will try again...

[DesignsOnline]

Managed to get them off thr phone...

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