Algae Scrubber Basics

[karimwassef]

Originally Posted by Floyd R Turbo

I would agree that algae does not seem to get light exhaustion, but that you can get photosaturation depending on the intensity level

Meaning, if you have too much intensity, then you hit a point where you won't grow anything. But if you find that right level, you can run it as long as you want.

That is also assuming nothing else changes, meaning, available nutrients. So if you start off with a bang and then over time your available nutrients drop significantly, your light level then might be too much.

Apart from dimming, the only way to adjust intensity is to shade, diffuse, or adjust position/distance. But it's a moving target since everyone's tank is different.

I think the nutrient content and flow rate need to match up to the intensity. The three in balance would allow constant operation. I have a lot of flow and you know my nutrient situation is the equivalent of an outdoor pond...

[karimwassef]

Originally Posted by MorganAtlanta

Flush it

Ummm.. A pound of hair algae won't go down easy... It might have when fresh, but after rotting for a couple of days, it's "gelling"

[karimwassef]

I am most dissatisfied with the uniformity of the flow out of the slit. I really need sone better design help here.

I could increase the pressure with a smaller slit to flood the inlet pipe, but that would reduce the flow.

I could even go to directional streams (drilled holes pointing at the screen), but that's less flow again.

I can go double inlet, but that'll only help a little given that I have a 2 foot span in a 2" pipe.

I can create a cascade of pipes to force uniformity but That would be huge.

...

[Floyd R Turbo]

Originally Posted by karimwassef

Holy frijoles! A pound of algae stinks to high heaven in the trash after a day!! The garage is abominable! I've never experienced this before, but I've never had this much export before either.

Anyone else deal with this? I need to take it out immediately next time.

Yeah, I think I made that mistake once

Originally Posted by Myriam

I throw my algae (and chaeto as well) in my compost, outside.

I tried putting it in a planter on top of the dirt but it just dries up into a hard clump and doesn't seems to get "consumed"

Originally Posted by MorganAtlanta

Flush it

Originally Posted by karimwassef

Ummm.. A pound of hair algae won't go down easy... It might have when fresh, but after rotting for a couple of days, it's "gelling"

I put it down the garbage disposal

Originally Posted by jason2459

Please don't put foreign algae into a sewage or drain system.

Never really gave it a second thought...

Originally Posted by MorganAtlanta

This is hair algae, not culerpa

^ that was my thought...plus, doesn't saltwater algae pretty much die off due to osmotic shock when placed in FW?

[Floyd R Turbo]

Originally Posted by karimwassef

I am most dissatisfied with the uniformity of the flow out of the slit. I really need sone better design help here.

I could increase the pressure with a smaller slit to flood the inlet pipe, but that would reduce the flow.

I could even go to directional streams (drilled holes pointing at the screen), but that's less flow again.

I can go double inlet, but that'll only help a little given that I have a 2 foot span in a 2" pipe.

I can create a cascade of pipes to force uniformity but That would be huge.

...

Once you get a fully mature screen, the algae will tend to want to grow into the slot/screen junction. When that happens it will divert flow to an area of less growth, which will then grow faster, diverting the flow away from it, etc...eventually the flow will be pretty balanced out. I don't know that I would spend a ton of time worrying about it right now, see if the issue persists. Unless of course, you happen to have bad OCD and a lot of free time.

[jason2459]

Originally Posted by MorganAtlanta

This is hair algae, not culerpa

I've also had more then just hair algae on mine.

Plus, it all depends on where you live. It could end up in a brackish or saltwater location. Edit, and some toilets utilize a brackish or saltwater water system to even start with.

[karimwassef]

Originally Posted by Floyd R Turbo

Once you get a fully mature screen, the algae will tend to want to grow into the slot/screen junction. When that happens it will divert flow to an area of less growth, which will then grow faster, diverting the flow away from it, etc...eventually the flow will be pretty balanced out. I don't know that I would spend a ton of time worrying about it right now, see if the issue persists. Unless of course, you happen to have bad OCD and a lot of free time.

hmmm I am working on keeping the OCD beasts at bay ...

my second biggest pain is the spurting from the ends... basically, it turns at the T and then goes to the ends. The closest end to the T (yes I'm offset) ends up creating an "open pipe" flow down that PVC leg. I blocked it up with epoxy, so now it spurts out and runs down the leg instead of the screen.

[Floyd R Turbo]

Sounds like too much flow, it's either due to slot pinching (long slot) or not a wide enough slot (so the hydraulics are pushing flow to the ends and it's "dumping")

[karimwassef]

Sounds like another vid is needed so you can diagnose.

[Myriam]

Originally Posted by karimwassef

ok. decided to add a plastic sheet cover - yes. I capitulated to popular opinion (and a couple of LEDs started to flicker).

Very nice!
But it's not going to melt?

[karimwassef]

why would it melt? The LEDs are barely warm since they're on a large metal sheet with a fan. The highest recorded temperature (check a few pages back) was about 100F...

[karimwassef]

what do you think?

[MorganAtlanta]

I hang my screen from the pipe using a loop of screen material, and drill holes in the pipe instead of a slot. Then I cover the loop with black plastic (from a contractor garbage bag), which serves as a light blocker, spray reducer, and also helps further smooth the flow. I find this system gives a nice even flow over the screen. This is a pic of my older implementation with a 3/4" pipe. My current one has a 20" long, 1" pipe with two 10"x10" screen sections. The scrubber is fed by a Jebao 8000 pump running full out, so lots of flow.

[karimwassef]

can you show your final assembly ?

[MorganAtlanta]

It is difficult to show because it is in an enclosed box squeezed inside the cabinet and the lighting isn't camera friendly But here you can see the water flowing out of the holes. It is not entirely uniform direction-wise, but with the black plastic in place it gets smoothed out. It is pretty uniform in terms of volume all the way across the length of the pipe, which was a problem I had with a slot. These pictures are without the cover that goes over top of the scrubber cabinet so that it is fully enclosed.

The spray-bar pipe is just friction fit into the elbow on the left, with a cap on the right end. To remove the screens for cleaning, I just slide the pipe out to the right. To re-install the screens, I just thread the pipe back through the loop of screen material. This version uses 1/4" screen material for the loops, but the plastic mesh works fine as well.

[karimwassef]

Ok. I get it.

Only issue is that my waterfall is gravity fed so I need to avoid backpressure from drilled holes as much as possible.

I'm going to adapt using your concepts though

[MorganAtlanta]

I have roughly 1/4" holes (maybe 5/16) drilled every half inch. I started smaller, then enlarged them until I got a the right volume of flow, even across the length, with low enough velocity that the water mostly "fell" rather than "sprayed" from the holes.

I also figured that the 20" schedule 40 pipe with holes will be much less likely to sag versus if it had a slot running the whole length.

[karimwassef]

It's not really sagging.

Ok. I have a new concept... I'm going to invert the slit.

So, I'm going to a slit on top of a 1" pipe. That pushes water up first creating a chamber "flooding" effect in the 2" pipe around it. Then the slit in that pipe carries the water down.

Then I'm changing the screen so that it wraps around the 1" internal PVC to grab the flow all around.

[karimwassef]

I'll post a pic

[Myriam]

Originally Posted by karimwassef

why would it melt? The LEDs are barely warm since they're on a large metal sheet with a fan. The highest recorded temperature (check a few pages back) was about 100F...

Really! I thought it would be hot, then it's good!

[karimwassef]

Maybe I should make a video of it. The 7020 rigid strip is really a good LED form factor. My biggest learning is that stacking a lot of them drives a lot of current at 12V.

I'm putting together a 500W fixture and that's 42A!!! So the LED isn't hot, but the 12 gauge wire feeding it is. I know I need to move to the 8 gauge, but I just haven't gotten around it.

[karimwassef]

how long can a scrubber screen go "dry"? This is 24 hrs







and what should I do to re-use it?

It's turned into a really solid coating... I can't scrape it off dry. I can rehydrate and scrape?

It's still green and I think it'll come back alive if I put it in water?

[MorganAtlanta]

Personally, I'd soak it, scrape it, then put it back in production and see what happens.

[karimwassef]

Is that the consensus?

[karimwassef]

on an aside. here is the progress on my other scrubbers - here's my in-sump floating ATS, Xenia scrubber and Chaeto cage: