Algae Scrubber Basics

[Snookster]

what did you cut the 1/8" slot in it with?
Thanks guys, :beer:

I used my rotozip. I think most guys use a dremel.

 

[jake levi]

slot

slot

Thanks, a dremel is what I was thinking. All these little bits of info add up in time saved and a better job.

 

[eums]

Been playing with the raceway idea and the closest I can get to the original ATS design most of you use here is that :

6 screens, 4 of which are lighted on both sides by CFL lights enclosed in acrylic, and 2 of them on 1 side only. Each screen is 16.5"x6" or 99 square inches. So according to your figures it should be enough to filter 99x5=495 gallons.

Each of the screen would have a pipe on top from the return pump, and although the flow per inch of screen would be lower than the recommended 35G/h/inch, it would get much higher when the tank is surging (which it would more often than in my original plan since the surge volume would be smaller).

The main drawback would be all the work involved in cleaning the CFL acrylic enclosures...

Sorry I don't mean to hijack this thread, I stop after this post I promise

I need to start a build thread sometimes, it's just that it seems to be the best place to ask ATS related questions :reading:

And who knows... since it seems well on its way to become Thread of the Month maybe I will be really lucky and someone will try this at home

A few things i would change on this if possible:
Go taller and utilize cheaper lighting such as 4' t5 bulbs, a 4' fixture using 6 bulbs would be ample light for a 16 " tall screen, this would give at worse over 600 gal of filter capacity (bottom 1" in water, top 1" in top mount, 2" on each side not as well lit and taken out)
with the shorter length it would be possible to feed the unit with a laguna pump (max flow 2000, using 100w)

So if you were to build this with mostly off the shelf stuff, cost wise you would be looking at $320 each for tek light fixtures, $175 for a pump and $120 a year for bulbs if changed every 3 months.
If you went the DIY route could shave costs, and you need the scrubber its self built.
not sure on the cost of the enclosure for this all, but would figure 600-800 if built as a one off(48"x96" 1/2" thick sheet runs ~475, rest is labor, yes this is overkill thickness but why not) and another 75-100 for plumbing. so ~$2k using off the shelf and designing it your self

Going with a single hung screen lit from both sides would be the simplest to maintain, (4x 12"by16" sections, allowing you to clean smaller sections at a time if needed).

This seems like the simplest to maintain option thats most economical in the longer run, using CFL's and surge seems more labor intensive to build and much more costly in build materials and bulb replacement .

Good luck with your build.

 

[Floyd R Turbo]

I plan on using a router for the next one I cut. I did the first one (notched slot) with a dremel and a universal bit, which I do not suggest, it's too grabby. You definitely need a mini-circular saw type of bit, or a cut-off wheel.

 

[salty joe]

Temperature of the sump area where these lamps operate probably runs into the 85F range with the doors closed, maybe.

That's great, but does not mean that the ambient temp of the lamps is the same as the temp of the sump. Not if they are enclosed, anyway.

This chart show operating efficiency with respect to ambient temperature, or the temperature of the surroundings, not the temperature of the lamp.

I'm aware of that.

This chart is probably gear towards recessed lighting in offices, so it really doesn't directly apply to our application, but it does give us some insight.

I disagree. In this case, the ambient temp is the temp surrounding the lamps. If the lamps are enclosed the ambient temp could be a lot higher than the room the lamp enclosure is in, the sump the lamp enclosure is in, what matters is the ambient temp surrounding the lamps.

But measuring the temp of the lamp/fixture and comparing to this chart would not reveal anything significant.

On the other hand measuring the ambient temp, or the air surrounding the lamps, would be useful.


It is from too much light. Intensity is too high, and after 4 hours, the algae stops growing and can reverse growth.

Never heard of such a thing. Can you provide a link or further info?

 

[JohnnyB in SD]

I plan on using a router for the next one I cut. I did the first one (notched slot) with a dremel and a universal bit, which I do not suggest, it's too grabby. You definitely need a mini-circular saw type of bit, or a cut-off wheel.

I cut mine using a fence on a table saw with blade up just enough to cut through bottom wall of pipe. The saw blade makes a perfectly straight 1/8" slit in the pvc. Quick & easy if you have the tool. Find a friend or neighbor with one if you don't.

 

[Floyd R Turbo]

I have a table saw, and that could work fine if you plan to rip the slot all the way across the length of the pipe. But how do you cut a slot in the middle of a pipe and leave 3-4" on each end uncut? You would have to position the pipe over the running blade, then lower it onto the blade, move it to the end of the cut, then lift it back off. You're asking for an accident, especially without kickback protection.

 

[Floyd R Turbo]

Temperature of the sump area where these lamps operate probably runs into the 85F range with the doors closed, maybe.

That's great, but does not mean that the ambient temp of the lamps is the same as the temp of the sump. Not if they are enclosed, anyways

This chart is probably gear towards recessed lighting in offices, so it really doesn't directly apply to our application, but it does give us some insight.

I disagree. In this case, the ambient temp is the temp surrounding the lamps. If the lamps are enclosed the ambient temp could be a lot higher than the room the lamp enclosure is in, the sump the lamp enclosure is in, what matters is the ambient temp surrounding the lamps.

My point is that we have no reference as to what the definition of "ambient temperature" is in this chart. That's all. For all we know, this study is of lamps in a test chamber with no reflectors, no enclosure, no ballasts in proximity, just a temperature controlled enviroment and a meter of some kind. I agree that keeping your lights cool extends the lifetime. I'm just saying don't read too much into that chart, it's just a reference. I think the more lights you put together and the more you restrict the air flow, the hotter it gets and the shorter the lifespan, and it's likely due to excess heat, which is why most 4-lamp fixtures have fans built in.

But measuring the temp of the lamp/fixture and comparing to this chart would not reveal anything significant.

On the other hand measuring the ambient temp, or the air surrounding the lamps, would be useful.

It depends on where you measure it I suppose, above, below, to the side, and how will you know what is meaningful? And I agree that with an enclosed fixture in a partially enclosed area the lamps will get hotter, etc, but really we're not talking about a great deal of efficiency difference here. I see what you're getting at, trying to get the perfect condition to grow the algae, and trying every angle, so I can appreciate that concern (at least, I think that's where you're coming from) but it's a question of diminishing returns - at what point do you get very little out of your time expended to maximize potential? Maybe you can squeeze an extra month or so out of the lamps, and if that is your goal and you can show that it can be achieved by proper cooling of an non-cooled fixture, then that's great - I don't think anyone has tested that out yet. It shall be added to my long list of experiments, unless someone beats me to it!!

It is from too much light. Intensity is too high, and after 4 hours, the algae stops growing and can reverse growth.

Never heard of such a thing. Can you provide a link or further info?

Google photoinhibition. I also talk about it in prior posts about LED lighting for scrubbers. Someone commented on one of my posts that photoinhibition doesn't set in for 4 hours, which forgot about. This is why you see some growth with too much light, but not as much as proper lighting.

 

[EleganceMan]

Hey guys...love the info in here...dont know if i skimmed past it or not but why do you guys like to do your ats's vertically and not horizontally? Is it just so you get more surface area or is there another reason?

 

[Floyd R Turbo]

It's really just a preference, but space is also taken into effect. A vertical screen lit from both sides will filter 1 gallon per square inch of dimensional area. So a 10x10 screen will filter 100 gallons adequately. If you go horizontal, you have to double the screen size, and if you only light it on one side, you also have to double it. So in effect, you need 4 square inches (2"x2") per gallon if the screen is horizontal and one-sided (which is always the case).

The horizontal style also usually requires some kind of turbulent oscillating action, like a dump bucket, to breach the boundary layer of the algae, whereas the vertical waterfall does that constantly. The boundary layer means that as deep water flows past a surface, the flow rate approaches zero the closer you get to the surface. In algae, this is where the exchange takes place. So the more agitation, the better exchange, the better your filter.

 

[jake levi]

Compact flo. size in pics

Compact flo. size in pics

SRusso what size compact fluor. is that in your 4 pics? Does give a lot of light with the foil backing.

 

[Floyd R Turbo]

Any reflector added to a CFL will help. The ideal reflector would reflect no light back into the lamp itself, and all light would be spread evenly across a given area.

I work in the commercial construction industry, and work with lighting quite a bit. A good reflector can make all the difference in the world.

 

[srusso]

SRusso what size compact fluor. is that in your 4 pics? Does give a lot of light with the foil backing.

Made a huge difference with color and brightness! Used Mylar from an old popcorn bag...

 

[travis32]

So, a few questions on my ATS build. It's doing good by the way. I'm on week 3 and It is a solid mass of green almost now. The hatches on the screen are still visible a little, but, it's not possible to see through the hatches anymore. The algae is fairly solid top to bottom!!! Yaay!! It's not thick yet like i was hoping for. That I could start harvesting a cup or two of algae, but, it's a solid mass. I'll take it!

I have harvested probably close to 3-4 cups of HA from my display over the last two weeks. I redid my rock work so I got access to areas I couldn't get to before and pulled HA by the globs. I Think that has helped the ATS process some, to harvest the nutrient consumers from the display. I do have a lot of macro in my sump, so I may have to start harvesting that too for the ATS to out compete everything, but, so far so good! I still have a lot of HA on corals that I would love to have go away.

One issue I have is flow. I'd love to use the full 300gph my pump can produce however, I can't because the slit in the pvc gets plugged and starts spraying water everywhere with the screen inserted. Do I have to make the slit bigger to stop water from spraying everywhere. I have to cut the pump back to around 1/4 to 1/2 flow. cutting it down to possibly under 100 gph to 200 gph. The PVC pipe sprays the water off the screen. It's in an enclosure but water still splashes out.

Any suggestions on how to control the water Spray so the water stays flowing across the screen? One other effect I hate about the water spraying off the screen... It's the noise. It's like someone very forcibly peeing constantly. It's not a light trickle. When it just flows across the screen, you barely even know the ATS is setup other than a low gurgle from the drain.

So, I'd like to limit the noise and increase the flow over the screen and reduce the preasurized spray off the screen.



Thanks!

 

[TheFishMan65]

Travis do you have a picture? The force of the water is supposed to keep the algae from growing into the slot. Are you cleaning it weekly? I think someone else had this problem and they blocked the light from reaching the first bit of screen so the algae did not grow there.

 

[Floyd R Turbo]

It sounds like you did not cut your slot wide enough. If you used a #7 mesh plastic canvas, which is 1/16" thick, a 1/8" slot will be all you need. Also it this a very small screen (width)? I think it was fppf that posted a pic a ways back in this thread where he cut out the horizontal sections of the screen towards the top to keep algae from growing on it and allow the flow to be more even. Here it is

http://www.reefcentral.com/forums/showpost.php?p=18446136&postcount=517

As for your flow rate, yeah you want 35 GPH/in and it really makes a difference when you actually get that flow rate (test it, don't trust the pump spec sheets and head calc)

And post pics...

 

[dogstar74]

As well as widening the slot, You could cut a piece of 1.5 inch Black ABS pipe to fit over the 3/4" spray bar. This should shield it from the light enough to prevent algal growth.

 

[travis32]

I can post one later. I was just happy to see algae growing. I see posts of people that clean off mounds of algae by the buckets from their screen, I assumed the screen would turn in to a furry array of multiple macro and micro algaes? Would it not? I didn't think it had grown enough to clean it. I guess it's a good question, I cleaned it two weeks ago because it was full of brown algae. How full should it be and should it just be slimy green algae. I was thinking the algae would grow in in layers. So the first 10 or 1000 layers are micro single celled algae, and the outer layers would evolve into more nutrient consuming algae such as macro algae like hair algae and the likes?

 

[TheFishMan65]

Clean it every week. Look I learned something from reading this thread

 

[travis32]

I used the dremel cutting tool that came with my dremal. The cut wasn't overly straight and I created some "toothy" cuts. (not the easiest cutting round pipe with a hand held dremel.)

I think I need to pull the spray bar and even out the cut some and make it slightly wider. I agree, having the max flow would help more water to be purified and turned over and would help the algae to grow faster removing more nutrients even faster.

My wife had some extra canvas laying around for doing art projects. (Which she started and never finished). So I have no idea what the thickeness of the canvas is. It fits fairly well into my spray bar, but given my uneven cut, it takes some rocket scientry to get it back into place.