Experimental algae scrubber

[Paul B]

I have been experimenting with this concept and so far the small version grew an enormous amount of algae so I built one on a larger scale. It is basically just a cotton sheet suspended over my tank by an acrylic tube that has holes drilled in it which tank water drips through slowly flowing over the material then back to the tank. A light is hung in front of it. Soon, hopefully, it will be covered in algae.

 

[DaveK]

Hi Paul,

This looks like an interesting project. I have a couple of questions for you about it.

Was there any reason for choosing a cotton sheet over the more conventional plastic mesh material typically used in algae scrubbers?

Do you worry about the cotton sheet rotting out quickly? In my planted tanks I sometimes use cotton thread to tie down plants, and it rots out in a month. I would tend to think a cotton sheet in SW would rot quickly also.

Do you get a lot of evaporation from your algae scrubber? If so, would you enclose it in plastic or glass?

Thanks

 

[cracker]

Paul I'm interested in how much water flow You have over the sheet.. Speaking of sheets. Do You mean something like ,material for a cotton bed sheet? Thanks

 

[Paul B]

Hi Paul,

This looks like an interesting project. I have a couple of questions for you about it.

Was there any reason for choosing a cotton sheet over the more conventional plastic mesh material typically used in algae scrubbers?

Do you worry about the cotton sheet rotting out quickly? In my planted tanks I sometimes use cotton thread to tie down plants, and it rots out in a month. I would tend to think a cotton sheet in SW would rot quickly also.

Do you get a lot of evaporation from your algae scrubber? If so, would you enclose it in plastic or glass?

Thanks

 

[Paul B]

I have a plastic screen in my algae trough. I chose cotton (actually, it is a Tee Shirt) because of the "wicking "action. I want the thing completely wet. Water does not absorb on screen and from tests it doesn't work as well. I did an experiment and draped a piece of cotton sheet over the side of my algae trough and it became completely covered in thick algae in a few weeks. It even started growing off the sheet like a lawn with just a tiny bit of water flowing on it. Water flows very slow over cotton.
The cotton should last a couple of years as I find clothes under water all the time when I dive here in NY. The piece I have had on there for 6 months shows no deterioration yet. There is very little water flowing over this, just enough to slowly drip off the bottom edge back into the tank. I have maybe 7 tiny holes in the tube where the water drips out keeping the cotton wet. I can easily change the material or clean it as it just slides off the tube. If it works as well as I think it will, I will remove the algae trough and make this much longer. It is an experiment like everything else I do.
I don't care about evaporation as I built an ATO that takes care of that.

 

[Paul B]

This is the original experiment. This was a small sheet of cotton material draped over the algae trough. Water is not even pumped over it, it is just wet from one edge laying in the water flow inside the trough. I peeled algae from this to seed the new device. This grew in a few weeks.

 

[DaveK]

That's quite interesting. This could be a whole new way to do algae scrubbing.

 

[Paul B]

I hope so

 

[cracker]

Thanks Man, Thinking out of the box once again. I have been dumping a lot of water over a plastic mesh screen for months with a lot of light. All I get is a bunch of brown stuff. May I ask, Are You getting close to the same growth in your trough with the screen? Thanks

 

[Paul B]

My trough used to grow algae, then it filled completely with tiny tube worms so much in fact that it overflowed and I had to clean out half of it. I put cotton cloth on the clean half a few weeks ago and that started to grow algae. It is to soon to tell if any of this will work. I need another 6 weeks to experiment. At that time I may tweek something like the flow of the light.
I don't like being in the box with everyone. I like to do my own research even if it comes out bad. Everyone (including myself) was growing algae on a screen, I want to try something different which may or may not work out

 

[Floyd R Turbo]

That's so weird, just today I was having a conversation with someone about different material for screen, and fabric was brought up. I think cotton would deteriorate eventually but some other kind of fabric might work.

 

[Paul B]

Cotton will for sure deteriorate, but at that time, I hope it will be covered in algae and it will be time to change it anyway. It is practically free.

 

[StirCrayzy]

When it fills with algae, is the plan to clean off the excess, or just disposing and starting clean?

 

[Paul B]

If the cloth isn't to deteriorated I will just scrape it off. Or else I can easily replace it. I have plenty of Tee Shirts. I am figuring in the slow deterioration to help the algae grow. But as I said, it is a test

 

[cracker]

Well said ! I have many old tee shirts that seem to have shrunk mysteriously over the years. I wonder if color would be a factor.

 

[Paul B]

I am not sure about color, but don't use any of those fishing Tee Shirts.. Fish hate that

 

[cracker]

I bet Your right about the fishing tee's. I hope my fish don'y know that I fish. Wouldn't want them to live in captive fear. LOL Anyway the cotton is a great simple idea. The natural the fibre itself would make it easy for algae to attach. Get Your favorite seamstress to stitch a loop in the top, slide it over the manifold. No squirting from the ends etc.

 

[Paul B]

The thing started to grow algae from the top down. I added some iron paper clips to the cloth to see if the algae grows faster in those places. It's a test

 

[Floyd R Turbo]

pics!

 

[Paul B]

Floyd, look at the first picture I posted and envision light green streaks of algae going from top to bottom.