Algae Scrubber Basics

Probably would work. 2 or 3 led's should be fine. If you can turn the waterfall towards the glass, you could put the led's on the outside and not have to deal with waterproofing them.

Also is the upflow option, by putting a long narrow screen down in the second chamber, and attaching an open air tube to the bottom of it, so the bubbles flow up the 1" section. This version also allows an external led... probably 3 of the ones you posted.

That's what i did on my overflow scrubber, led behind the back glass.
 
The theory has always been that they are the cause of "pod circles", however there was never any concrete proof of that. It was just a best guess IMO. I think another mechanism is at work there, and pods may or may not be to blame. I have seen some screens where growth is strangely very concentrated, and you will see a lump or ball of algae growth on an otherwise non-productive screen. This is usually temporary, but it usually coincides with not cleaning because it doesn't look like it needs it. The lower layers die off and the lump detaches.

Also since the emphasis has been strongly toward making sure the screen material is properly roughed up, this has been less common of a problem.

There is even another possible explanation, but I really feel that pods are not the issue. I know people that have never rinsed their screen in freshwater (only saltwater, or not at all) and they don't have pod circles.

Hm. Here is my beef with the pod theory. I've never seen "pod circles" on algae covered live rock or glass. Why would an ATS manifest the circles and nothing else? Makes no sense.
 
banker, the difference would be the growth medium. Most rock or glass does not have thin high speed laminar flow across it. So you can't really make that direct comparison.

Halo, I like your design. One thing to consider though about your slot pipe idea. There is no allowable head pressure. Meaning that your water entrance point is just below the top of the baffle, which is fine at first. What happens inevitably is that algae will grow on the screen and creep upward into the slot/screen junction. This will tend to slow down flow through the slot and water will pour over the baffle, bypassing the scrubber. this will become more and more of an issue over time

Since you only are able to light one side anyways, what I would do is something similar to what thebanker did, force all the water to flow down a short spillway where your screen is attached. You could actually do this with your pipe idea, but cut 1/4 of the pipe out and orient it such that the quarter-cut section is facing toward the back of the tank (where the light is). Find a way of securing the screen to the edge of the slot opening or just below it. If that makes sense.
 
Hm. Here is my beef with the pod theory. I've never seen "pod circles" on algae covered live rock or glass. Why would an ATS manifest the circles and nothing else? Makes no sense.

I agree, the pod theory makes little sense. Why would a colony of pods appear in the centre of the screen? How could the pods multiply like a bacterial colony without an adult stage on the screen? How could they travel upstream? What is the food source (healthy GHA!)?
 
Halo, I like your design. One thing to consider though about your slot pipe idea. There is no allowable head pressure. Meaning that your water entrance point is just below the top of the baffle, which is fine at first. What happens inevitably is that algae will grow on the screen and creep upward into the slot/screen junction. This will tend to slow down flow through the slot and water will pour over the baffle, bypassing the scrubber. this will become more and more of an issue over time

Since you only are able to light one side anyways, what I would do is something similar to what thebanker did, force all the water to flow down a short spillway where your screen is attached. You could actually do this with your pipe idea, but cut 1/4 of the pipe out and orient it such that the quarter-cut section is facing toward the back of the tank (where the light is). Find a way of securing the screen to the edge of the slot opening or just below it. If that makes sense.

You mean like this?

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That would mean it would overflow over the lower side of the pipe, which is perfect as it would mean I wouldn't need to cut a slit or deal with that. I think I could mount the screen like that with zipties.


How effective are these for filtration? What else would be needed to successfully filter a system?
 
Yeah that's exactly what I was describing, or better.

Now your decision is which version to run: waterfall, submerged, or combination. The driving factor will be the height of your last baffle. you could make that baffle adjustable so you could have options.

Baffle in a low position, the majority (or all) of the screen will be a waterfall. Baffle in high position, the screen will be submerged. Mid height, you could get both.

I'm a waterfall guy, but submerged can work well in certain situations, and sometimes it's all you can do. The whole thing centers around water flow rates. You have to have water movement across the growth substrate and it must have some kind of speed or turbulence to it.

With a vertical waterfall, this is inherent.

With a submerged scrubber, you must make this happen. In your case, you need something causing the water to mix up near the submerged portion of the screen. You could do this with a pump shooting water up from underneath (difficult) or an airstone (less difficult) or you could make the screen slanted and place something under it (like a piece of acrylic) to force the water to run along it, like a dam spillway.

I would opt for the combo approach in this case

The portion that is underwater would have a 'river' of water flowing across it underwater; the part of the flow above the waterline would shoot down underwater to give you this flow. However, the intensity of this underwater flow will probably dissipate pretty quick if the slope is constant. So then what you might do is curve the back plate a bit so that the laminar input flow is more or less forced to follow the curve.

This curve couldn't be too drastic or else you lose the effect of light, but I can foresee starting with a flat maybe 10 degree slope from the pipe to the water level, and then a couple 10 degree bends in the material under the water line. That should do it.

So I just came up with that off the top of my head, maybe it will work, maybe not. But I think a combination of both types would be best to try if you have the space to do it.
 
Most fish will readily eat pods. Having "too many" in the system isn't ever an issue. They become problematic in scrubbers that aren't scraped frequently, because they will nip off bits of algae that then float around your entire system, if I understand correctly.

For Red Turf, there are small pods that will decimate a screen in no time. They are super tiny, and the name escapes me at the moment, but Morgan Lidster will know. I've watched them take out a screen in a week, and weekly scrapping will reduce them, the high pressure rinse of the screen with fresh water post scrapping will remove most of the rest, but weekly maintenance is the only sure thing.
 
Yeah that's exactly what I was describing, or better.

Now your decision is which version to run: waterfall, submerged, or combination. The driving factor will be the height of your last baffle. you could make that baffle adjustable so you could have options.

Baffle in a low position, the majority (or all) of the screen will be a waterfall. Baffle in high position, the screen will be submerged. Mid height, you could get both.

Doing midheight would it be possible for the water flow from the exposed screen, in addition to the flow made by the pump, would there be enough water flow for proper growth?

I'm a waterfall guy, but submerged can work well in certain situations, and sometimes it's all you can do. The whole thing centers around water flow rates. You have to have water movement across the growth substrate and it must have some kind of speed or turbulence to it.

With a vertical waterfall, this is inherent.

With a submerged scrubber, you must make this happen. In your case, you need something causing the water to mix up near the submerged portion of the screen. You could do this with a pump shooting water up from underneath (difficult) or an airstone (less difficult) or you could make the screen slanted and place something under it (like a piece of acrylic) to force the water to run along it, like a dam spillway.

I would opt for the combo approach in this case

The portion that is underwater would have a 'river' of water flowing across it underwater; the part of the flow above the waterline would shoot down underwater to give you this flow. However, the intensity of this underwater flow will probably dissipate pretty quick if the slope is constant. So then what you might do is curve the back plate a bit so that the laminar input flow is more or less forced to follow the curve.

This curve couldn't be too drastic or else you lose the effect of light, but I can foresee starting with a flat maybe 10 degree slope from the pipe to the water level, and then a couple 10 degree bends in the material under the water line. That should do it.

So I just came up with that off the top of my head, maybe it will work, maybe not. But I think a combination of both types would be best to try if you have the space to do it.

Not exactly sure I follow you there, do you have any pictures by chance?
 
Most fish will readily eat pods. Having "too many" in the system isn't ever an issue. They become problematic in scrubbers that aren't scraped frequently, because they will nip off bits of algae that then float around your entire system, if I understand correctly.

I have never had this issue because I shake my scrubber before I clean it to get some pods off the canvas and some algae always flies off. That algae disappears due to the voracious apetite of my turbo snails or my emerald crab or the hermits. Idk which one devours it, but I never really worry about a loose piece of algae in my tank. I have let pods run wild on my scrubber for 3 weeks and nothing happens. The only bad thing that happens when I leave my scrubber for extended periods of time is a small amount of cyano which can be easily removed if I just adjust the flow.
 
I would like to try a second bulb and think the spotlight variety would fit best for my application. Is anyone having decent growth with the LED spots available at the BB stores? If so what color bright, cool, or warm? If not LED are the spot CFL's an option?
 
Halo you would probably need two 3-watt LEDs for that. Maybe three of them. Yes it can be the only filter.

Chris you would want LED grow bulbs from hydroponics places. If CFL, you want warm.
 
Doing midheight would it be possible for the water flow from the exposed screen, in addition to the flow made by the pump, would there be enough water flow for proper growth?

Should be enough flow I would think

Not exactly sure I follow you there, do you have any pictures by chance?

I would if I had time, sorry.

Imagine that you are looking at a cross section from the side - through the pipe. From the edge of the pipe where the water spills out, you would have a piece of material that runs the length of the pipe hanging down, with the screen laid on top of it, then that is angled such that the bottom of that is closer to the back panel of the tank (creating about a 10 degree spillway). As the water flows further down (and eventually underwater) you would angle the spillway a little more (closer to the back panel) and a little more, so that the water that flowed down it was 'forced' to flow down and into the substrate (screen) instead of dispersing into the water column. Does that help?
 
Growth is looking great and GHA looks like it taking hold. I can say that the skimmer has slowed to turtle speed and barely any waste is created. When it does it's very concentrated at that but fakes a month or two until it needs cleaning. I haven't seen touch of a change in the pH but I do sit around 7.6 respectively. Tank looks great, good coral growth and now dialing in the LEDs to get good coloration. I do have one question, what are the tiny air bubbles being created by the algae on the screen? Flow seems to be great but half way down I have numerous tiny air bubbles in the ATS. Good thing/bad thing?
 
Question for the scrubber set:

I'm currently running chaeto and biopellets. My scrubber is now almost fully "ramped up" in terms of consistent growth.

Would you / should I transition away from biopellets? Should I gradually ditch the chaeto too?
 
I need opinions on my lighting. I had old lights that I wasn't using due to me taking down my old tank. I was wondering if how I have the lights is ok or should I go a different route? On the right is led and on the left is a t5 set up on of the bulbs is currently an actinic. I planned on changing the t5 bulbs since they are almost a year old but wasn't sure what to change them to and wanted opinions before I did anything.

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Thanks
-Chris
 
Pellets will usually slow a scrubber, so stopping the pellets should help.

Chrisg's lights do need changing. White LED won't work well, and actinics won't work at all. And, they would be more in the middle of the screen.
 
Hm. I'll keep running the pellets until they sorta dissolve away.

White LED's do work on these scrubbers, but not too "cool" of a white. I'll grant that the algae growth is not as good as the red frequencies though.
 
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