Algae Scrubber Basics

[Floyd R Turbo]

Ideally how far should the mesh be inserted into the pvc?

Steve

I'll cover this one in Part 2 also. I only insert the screen about 1/4" or so, so that it sticks up about 1/8" above the inside of the pipe.

I've seen builds where it's inserted all the way to the top of the inside of the pipe, and held with a single zip-tie in the middle of the screen. This is fine as long as the inlet to your overflow pipe has a strainer on it that would prevent anything from entering the pipe. Otherwise, if a snail or anemone got into the pipe it could get snagged on the screen and partially or completely block the flow, and back up your DT.

I don't know if there is any advantage to full insertion vs. minimal insertion, inserting it further may even the flow out a bit, but I haven't noticed any glaring issues with the way I do it.

So my opinion is minimal insertion is fine, but it should protrude a little bit into the pipe.

 

[SPotter]

cutting the slot.....

cutting the slot.....

I was able to lower the blade on my table saw enough so that I was able to run the pvc over the blade and have it score a straight line for the length of the pipe without cutting all the way thru. I then marked the area I wanted to finish cutting out with my dremel and was able to keep a very straight line based on what the table saw did and by using a lower speed on the dremel. I'll try to get some pictures up later.

 

[Floyd R Turbo]

fppf posted this idea way early on in the thread

has anyone tried this technique? It originally was posted as a way to further prevent algae growth at the slot junction with the screen, but I wondered if it also caused a more even or less even flow across the screen. I was thinking that it might allow water to pass easier with the horizontal parts cut out, meaning that you would need a higher GPH/in flow rate in order to get even coverage, but that's just a guess.

 

[Floyd R Turbo]

Here's today's harvest - 3rd week in a row of stellar growth!

 

[srusso]

What is the weight of your harvest? Nice work!

 

[Floyd R Turbo]

I still need to get a portion scale. No clue what it weighs.

 

[Robert Patterso]

It's all in the slot tube...

I would say plan on cutting three or four of them and chose the best one. Best being straightest, cleanest cuts.

Probably the best way to cut the slot it take your tube to a machine shop and have them to cut an 1/8th" slot with a carbide endmill. It will take them no more than a couple minutes. I know, I'm a machinist and thats how I did it. Took me about 30 seconds at most. Nice and straight.

 

[Floyd R Turbo]

Probably the best way to cut the slot it take your tube to a machine shop and have them to cut an 1/8th" slot with a carbide endmill. It will take them no more than a couple minutes. I know, I'm a machinist and thats how I did it. Took me about 30 seconds at most. Nice and straight.

Good tip, I googled that, it looks like a good idea. Sounds about the same as the router idea.

 

[Robert Patterso]

They can just put in a vise or on the mill table itself and plung the endmill in at the starting point and go. Very clean cut and quick.......

 

[Robert Patterso]

I am giving some serious thought to building a 3D scrubber. I like the idea of getting more growth. My open scrubber works great, would like to improve on it. Maybe take my skimmer off line in the future

 

[Robert Patterso]

Does it matter whether or not if the 3D box is open at the bottom. Will it still work as well?

 

[srusso]

Does it matter whether or not if the 3D box is open at the bottom. Will it still work as well?

I am experimenting with this right now. My open scrubber uses the water surface tension to build up 3D growth. Nothing like the standard T5 build produces but there are a ton of changes still needed with my scrubber.

 

[Floyd R Turbo]

I would venture to guess that you will get better 3D growth with a closed-bottom box, simply because the water must stop falling vertically and shift to horizontal flow at the bottom, which allows buildup of the water column, promoting thicker growth, and then it's a vicious cycle. You can probably get partial 3D growth with an open bottom if you put acrylic panes very close (say less than 1 inch) from the screen surface on both sides.

 

[TheFishMan65]

???

if you put the screens [acrylic box] very close (say less than 1 inch) from the screen surface on both sides.

 

[srusso]

???

The algae begins to grow 3D on its own. Basically starts protrude off the screen. If this algae touched an acrylic "wall" or splash guard (that was less then an inch part). The algae will begin to attach to that wall, then air pockets will form, and you will begin getting 3D growth.

I have been considering doing this... reason being, my splash guard gest salt creep on it which starts to block light. If it was closer it would get "wet" more often. I think I could build it for very cheap, it could be built from very thin acrylic.

 

[TheFishMan65]

Last edited by Floyd R Turbo; Today at 11:05 AM. Reason: see TheFishMan65's comment below

I think you missed that srusso, but thanks for qualifying. But that leads to another question. I thought the 3D was just that the water got further from the screen and slowed the water until the box started to fill. Are the air pockets important?

 

[srusso]

I think you missed that srusso, but thanks for qualifying. But that leads to another question. I thought the 3D was just that the water got further from the screen and slowed the water until the box started to fill. Are the air pockets important?

The air pockets get trapped by the algae, this allows growth to build up/out/away from the screen. I tired to get a picture of my scrubber last night that demonstrates but it doesn't do a good job of it...

 

[srusso]

I guess you can see it... Here is the picture from last night.

See the light green area is beginning to grow outward. If you could see it in person, you would see that there are tons of little trapped air bubbles, oxygen being produced by the algae.

 

[Floyd R Turbo]

If you watch my youtube vid of my screen when it's full up at about the 0:45 to 1:00 point you can see some of the trapped air

http://www.youtube.com/watch?v=Ex8q7cmyAAE

And you can see some at mid-week in this one at 5:35-5:40

http://www.youtube.com/watch?v=LrNvqtk7t18

If you have decent GHA growth, you should get trapped air without an enclosure. Once I had an air pocket in the scrubber box that was 1 inch tall and 8 inches wide, with 2" of 3D growth over the top of it!

 

[Ehgemus]

Ok I'm going to give this a try. Here is what I have going.

I feed the scrubber for my return pump.

This is day 1.