Building First Scrubber Questions

[Hemlock]

Hi All, I just joined the site and have some questions...I going to build a scrubber for my 90g tank that has high nitrates that I'm tired of fighting. My questions are screen size 10x10?? two sided because I have a big sump in the basement so I have plenty of room.
Lights--I would like to stay simple for now but not understanding the cfl wattage thing but I know 2700-3500 is a good range with clip on reflectors. what size pvc should I use? I have a mag 5 for a pump so i could use that.
Any advise would be appreciated.
Thanks,
Don

[SantaMonica]

Welcome.

3/4 inch pvc is good.

Scrubbers are sized according to feeding. Nutrients "in" (feeding) must equal nutrients "out" (scrubber growth), no matter how many gallons or liters you have. So...

An example VERTICAL upflow or waterfall screen size is 3 X 4 inches = 12 square inches of screen (7.5 X 10 cm = 75 sq cm) with a total of 12 real watts (not equivalent) of fluorescent light for 18 hours a day. If all 12 watts are on one side, it is a 1-sided screen. If 6 watts are on each side, it is a 2-sided screen, but the total is still 12 watts for 18 hours a day. This screen size and wattage should be able to handle the following amounts of daily feeding:

1 frozen cube per day (2-sided screen), or
1/2 frozen cube per day (1-sided screen), or
10 pinches of flake food per day (2-sided screen), or
5 pinches of flake food per day (1-sided screen), or
10 square inches (60 sq cm) of nori per day (2-sided screen), or
5 square inches (30 sq cm) of nori per day (1-sided screen), or
0.1 dry ounce (2.8 grams) of pellet food per day (2-sided screen), or
0.05 dry ounce (1.4 grams) of pellet food per day (1-sided screen)

High-wattage technique: Double the wattage, and cut the hours in half (to 9 per day). This will get brown screens to grow green much faster. Thus the example above would be 12 watts on each side, for a total of 24 watts, but for only 9 hours per day. If growth starts to turn YELLOW, then increase the flow, or add iron, or reduce the number of hours. And since the bulbs are operating for 9 hours instead of 18, they will last 6 months instead of 3 months.

HORIZONTAL screens: Multiply the screen size by 4, and the wattage by 1 1/2. Flow is 24 hours, and is at least 35 gph per inch of width of screen [60 lph per cm], EVEN IF one sided or horizontal.

LEDs: Use half the wattage as above. 660nm (red) is best. You can mix in a little 450nm (blue) if you want.

Very rough screen made of roughed-up-like-a-cactus plastic canvas.

Clean algae off of the screen:

Every 7 to 21 days, or
When it's black, or
When it fills up, or
When algae lets go, or
When nutrients start to rise

[Hemlock]

So normally the cfl bulbs say 23 watt but equivalent to 65 watts I wxould go with what number?..based on the feeding I'm going to go with a 10x9 or10x10 two sided screen... Does that sound right?

[SantaMonica]

The real watts... the lower number.

I don't know what your feeding is.

[Hemlock]

Thanks, I have 2 tangs so I feed about a half a sheet of nori a day maybe a little more. I also feed some pellet a pinch or two.. 90g tank so what do you think about screen size with light on each side? Just don't want to screw it up...lol Thanks again

[SantaMonica]

How many square inches of nori, and how many grams of pellets

[Hemlock]

16 square inches of nori and i don't really know how many grams maybe 2-3

[SantaMonica]

Sounds between 2 and 3 cubes.

3 cubes = 36 square inches = 6 x 6 with 36 total CFL watts = 18 watts on each side for 18 hours/day.

[Hemlock]

Wow that's tiny for that big of a tank and with high nitrates,

[Hemlock]

I also should mention that I bought 43 watt cfls because I thought the screen was going to be a little bigger, so should I just use the 43w ones on 9hrs a day or go get the 18w and up the wattage if needed?

[Hemlock]

I could probably use the flood type instead since the screen is 6x6?...and again I shouldn't use a bigger screen and cut it down when my nitrates that are high now (around 40-50) come down first? Thanks again

[Hemlock]

Anybody??

[SantaMonica]

More wattage is better until it turns rubber yellow.

[Hemlock]

ok, I got it running but with position of clip on lights and a 6" screen I'm getting a lot of splashing into the center part of sump...can I make it longer so it go's into the water and doesn't splash or will that mess everything up?

[SantaMonica]

It will work.

[MorganAtlanta]

Make it longer so it dips into the water an inch or two. The unlit lower portion won't hurt anything.

[Hemlock]

Thanks, I was able to make it work but instead of using a pump I ran it off one of my drain lines into the sump, I had to point the lights down a little but I think it should work. I ended up getting 23 watt flood cfls because I couldn't find 18w where I went..I hope it works...lol

[Hemlock]

Hi all, going to take some pictures today and show you my setup. It's day six and I'm probably going to wait a little longer than the seven day cleaning because it's got good even growth mainly dark brown, it has a good amount of little bubbles on the screen with the algae...does this mean anything? I thought I read something about bubbles?? or is it just breaking in?
Thanks,
Don

[Hemlock]

372637273728

[Hemlock]

I'll get a couple more pics later

[SantaMonica]

Let it go 14 days. Bubbles could be anything.

[Hemlock]

Will do..Thanks

[Hemlock]

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Day 14----Should I clean it? Both sides? let me know what you guys think. It looks like the higher flow gets thicker stuff growing but let me know...Thanks

[SantaMonica]

Yep clean it all off.

[Hemlock]

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Day 6 after cleaning, should I clean tomorrow or let it go to 14 days...Also how does it look? I'm getting a bit of cyano in the sump area right below the scrubber, should I be worried?
Thanks,
Don

[SantaMonica]

It's dark... need to clean it. Your light must be leaking into the sump to grow the cyano. Shouldn't hurt anything but it's better if the light does not leak.

[Hemlock]

okay, I'll clean tomorrow or maybe tonight, does it look like it's pulling nutrients out of the water(WORKING)?...The problem with the light is one side has enough room to direct it at the middle of the screen and the other due to space issues has to to be pointed down a little so if you have any suggestions for different lights any help would be appreciated. Thanks SM

[SantaMonica]

If it's growing, it's pulling.

[Hemlock]

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A few updated pics left to right 1/13/13, 1/14/13 1/17/13 I don't know if I should let it go to 14 days or clean it...had a death in the family so it's about 10 days now...just keeping you updated! Also I corrected the light issue, here's a couple pics3845384638473848
Let me know what you think so far and if you think I need to change anything.
Thanks,
Don

[Floyd R Turbo]

Looks better with the lights pointed at the screen right. FYI you can remove the reflectors, the CFL floods do not need them, they are just taking up space.

I would give it a cleaning, rub away the dark algae with fingertips, scrape and/or scrub those areas if you need to, leave as much green on it as you can, then check again in 7 days.

[Hemlock]

Thanks, yeah I know I don't need them but they help me position the lights better..I'll clean it and leave the bright green stuff. Thanks again

[Hemlock]

Hi all, here's a couple more pics this week at 9-10 days from both sides...Let me know what you think...The side with more green was left on by accident for 24hrs but it seemed to green up more than the other. I'm also getting a pungent odor from the tank that I've never had before?? Any thoughts? Thanks
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[Hemlock]

Anyone??

[SantaMonica]

If algae is dying on the screen, that could be it.

[Hemlock]

Thanks sm I think I'm going to clean it tonight should I leave the green on or try to scrape everything off?

[SantaMonica]

Scape it all in case there is dead stuff.

[Hemlock]

Hi All, I missed a week but wanted to post some pics...Nitrates still high around 40 but the scrubber is starting to work I think, as usual let me know what you think. Thanks, Don
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After Cleaning 39943995

[Floyd R Turbo]

The last set of pics look like you only cleaned about half of that algae off. Your screen is very mature, at this point I would be cleaning all of algae off (scrape all the surface algae off), and then if it were my screen I would be cleaning all of the dark brown/red algae that is in the holes off as well, by scrubbing with a stiff brush. You may only want to do this 1/4 of the screen at a time, over the next month. I try to keep that stuff (which is the roots of red turf algae) off the screen completely, because it doesn't grow as fast as GHA and also prevents it's growth at it's location, eventually.

The brush I use for removing turf is a grout & tile brush from Home Depot. It has stiff plastic bristles so it won't tear the screen apart, but when used in small circular motions, it takes that red stuff right out and leaves the screen itself still covered in algae for seeding the next growth week.

Just my 2c.

[Hemlock]

Thanks Bud, the lower part is just to stop the splashing if that's what your talking about and yes I agree I should do a better job with that..which part should I clean a 1/4 at a time, the main part or lower? If I'm understanding correctly you want me to clean all the green (scrape) and only clean the lower part a 1/4 of the time thoroughly? Thanks again

[Floyd R Turbo]

No I am only addressing the effective growth area. I didn't mention the lower part, the lower screen section. That I would keep really clean, like scrub it hard every time.

I'm just referring to the area that has active green growth. In your last 2 pics, it looks like you just rubbed it with your finger to get the loose stuff off. I would scrape the screen until you can at least see the canvas pattern. One or two passes with a plastic scraper should do it - you don't need to really grind at it, just expose the mesh. Then pick a quadrant of the active area (upper screen) and scrub it a little extra with a brush. Maybe a toothbrush the first time, and do that to a different quadrant for 4 weeks and see how the growth returns. The point is that you do a little more aggressive cleaning to a part of the screen and see what develops. Honestly depending on the unique conditions of your system, it might grow better if you don't scrub it. But I don't know and neither do you until you try it. Scrubbing 1/4 of the screen isn't going to wreck the scrubber. if you're really worried about that, just do 1/8 for this week.

[Hemlock]

Hi All, just checking in and had a few questions, I changed my bulbs a couple of week ago to 43 watts a side and it hasn't turned yellow or anything but it still not getting my nitrates down at all so I don't know if I'm doing something wrong or what to think at this point because they should've come down by now?? Any ideas would be helpful....Thanks, Don

[rleahaines]

If nitrates are still at 40 I would check to see if you have any other things that are putting nitrates in the system other than food.

I am assuming your screen size is correct to the amount of food you are putting in. If you are running the scrubber 14 to 18 hours per day and have the correct screen size and flow of air or water, your nitrates should be going down unless there is something else putting them in. Are you using RODI water?

[SantaMonica]

Is it growing?

[rleahaines]

What test kit are you using to measure Nitrates?

[Hemlock]

Yes I use RODI, I feed nori and thera a spectrum pellet.
Yes SM it's growing, how well I thought pretty good. I'll try to post pics later.
I'm using API because they work pretty well with high nitrates...sps isn't doing all that great so just trying to figure things out.....Thanks

[SantaMonica]

Yes the growth pics from last month looked pretty good.