Algae Scrubber Basics

[mrbncal]

Yes ! :bounce3:

Just finished reading through all the posts . . . . .

Does that make any sense to anybody or am I doomed to certain failure ? :wildone:

Thanks in advance for your time and sorry about the long post...

Sylvain

Interesting design idea for sure. Hard to say at this point how it would perform. The "need" for the hair algae to be surged is not an issue as has been proven by the many users of the algae scubber. BUT...that does not mean that it wouldnt work well. Its a cool idea and I would like to watch it unfold. Good luck.

 

[mrbncal]

Allright, So I was just sitting here with my New brown, diatom slimy screen (day6) and I had a thought pop into my head.

It seems that all these scrubbers take a time to "Mature" and that the turf algae takes a couple of weeks at least to start showing up.

I just wonder if that's because newer systems need to shed the nutrients that promote diatoms, or is it a screen maturity thing.

Have any of you guys that have run an ATS for several months/years ever replaced the screen to see if green appears first? Or would you suspect having to start all over with the brown slimy algae, even though your system is used to producing the green turf algae?

In other words, is the green turf algae a sign of screen maturity, or a sign of system maturity?

A good test would be to have someone with a well established ATS take the original screen offline and replace it with a white straight from the Walmart new screen, and see if you get diatoms, or green turf growing in. The latter would tend to suggest this "break in period" is more a system shift, and not just a screen issue.

Curious,
Aaron

My two cents on this. . .

Recently my one year old scrubber screen dryed up when my pump failed to restart after an electrical outage. My tank had been running great up to that point. The lights on both sides of the screen made short work of the algae and the thing was bone dry to say the least. So I pulled it out and scrubbed it clean as I didnt want to have any of the dead dried algae color my water green. That was purely speculation as I dont know if it would actually do it. Just seemed like the thing to do. So the screen was for the most part back to white with some green stains (kind of looked like a St Patricks Day holstein cow . . lol . . . eh, sorry)

To answer your question yes I grew the same brown stuff you are growing, all over again. It was as if I was starting from scratch. The good news is I did not experience any death loss or severe fluctuations in pH or other parameters. I did however see an increase in algae in teh display tank for a week or two. Bubble algae sprouted up in a couple places also. But as I find them I pop them and they dont come back. During the two weeks following the drying incident I cut way back on feeding. This ticked off the fish but they never seemed to get very thin soooo...its all good. So its not the end of the world, or your tank, if you lose a screen. :wave:

 

[jake levi]

Snooksters frame

Snooksters frame

Hi Snookster good looking frame very much as I picture mine, is that 3/4" pvc? What size pump/gph?

 

[salty joe]

Floyd, that's an impressive harvest. You probably said so already-please let me ask anyway-how big is your screen? The Dr.'s tank is 125 and you have 4 T5s on the screen, is that right?

I was looking at a graph that showed T5s perform best around 95 degrees. Intensity dropped off at a fairly steep rate from there. I assume that the wattage consumed is constant no matter what temp the lamps are running. So from an effiency standpoint, a coolimg fan might be the way to go. Running too cool looked worse than running too hot IIRC in terms of intensity, so the fan would need to be tuned with a thermostat or something. Doesn't Icecap have a little DC fan with a thermostat?

Concerning the bleached algae on your nice little video, it could be that the algae against the acrylic got cooked. It very well could be a flow issue as you pointed out. How can we know for sure? Do you know how hot the enclosure with your lamps gets? One of those indoor/outdoor thermometers with little probes would tell you.

 

[Floyd R Turbo]

Floyd, that's an impressive harvest. You probably said so already-please let me ask anyway-how big is your screen? The Dr.'s tank is 125 and you have 4 T5s on the screen, is that right?

It's 20" wide and about 7" tall, and 2x 24W 24" T5HO PlantMax 3000K Red/Bloom lamps on each side, each with a TEK-II reflector, lamps centered 3" apart (vertically) and roughly 2.75" from the screen.

I was looking at a graph that showed T5s perform best around 95 degrees. Intensity dropped off at a fairly steep rate from there. I assume that the wattage consumed is constant no matter what temp the lamps are running. So from an effiency standpoint, a coolimg fan might be the way to go. Running too cool looked worse than running too hot IIRC in terms of intensity, so the fan would need to be tuned with a thermostat or something. Doesn't Icecap have a little DC fan with a thermostat?

I run no cooling fans, but neither do most fixtures with remote ballasts. Most 2-lamp fixtures do not run fans either, so I'm not so concerned. Could you post a link to the chart you talk about though? I would be interested to see what you're talking about.

Concerning the bleached algae on your nice little video, it could be that the algae against the acrylic got cooked. It very well could be a flow issue as you pointed out. How can we know for sure? Do you know how hot the enclosure with your lamps gets? One of those indoor/outdoor thermometers with little probes would tell you.

There's plenty of room for convective cooling of the lamps. As for the heating, with 78 degree water on the other side of the acrylic, whatever temperature increase occurs is wicked away very quickly. So "cooked" is not really accurate, because heat is not the problem. Also, algae doesn't really bleach out due to too much light, it just stops growing after a few hours (photoinhibition). If you look back at some of my posts, you will see that flow rate effects the color of the algae grown. The uneven flow I have in general (because of crosscuts/notches) causes strong green growth in higher flow areas, and lower flow areas are lighter green to yellow.

In my system, I have a drain on each end, so as the algae grows out from the screen and traps the water, it builds up a parabolic shaped water level. I use a slip-to-threaded female/female connector inside the corners, which stick up about 1.5" inside the box (the intent being to create a water trough at the bottom of the screen to reduce bubbles). The top 1" of the flooded area formed by the 3D algae receives good water flow, but then it forms a blockade of sorts that causes relatively stagnant water below that area. Once the growth completely fills the bottom area (below the 'minimum' water line created by the connectors), that water is essentially stagnant, and there isn't much water flow between that stagnant line and the parabolic curve 'trap'. This condition only occurs for a few days, toward the end of the week, but it is enough to choke off much of the algae in that area. I believe this is also due to the fact that the interior width of the screen box is 1.75", and this is probably about as small as anyone has made it. That's less than 1" of space on each side of the screen to the enclosure.

There has been much discussion here and elsewhere about running a fully flooded ATS. At this point, I would not recommend it, and would reserve such a design for experimental purposes only. Personally, my next iteration of design will probably prevent the box from being flooded and restrict 3D growth, at least to the point of blocking lower layers from laminar flow.

 

[Floyd R Turbo]

Just a reminder, if you haven't voted, this is the last week...

http://www.reefcentral.com/forums/showthread.php?t=1984888

I think this thread is going to run away with it though, 62.5% of the vote as of right now.

 

[srusso]

Yeah, I am finally done with my build

I do have a question, with the socks gone I now have mirco bubbles so how do I get rid of them?
Thanks

Your idea inspired me to do this little project!!

View attachment 143702

Took a empty bag of smart food popcorn. Cleaned it and put it on my ironing board. Covered it with a towel and ironed it. Once flat I cut ovals out of them

View attachment 143710

I just slipped them behind the bulbs. Look at the difference! One one the left has the DIY reflector.

View attachment 143711

and it seems to have made it much brighter!

 

[Coral C's]

The first three attachments would not open? The picture does look brighter, hmmm.
I had painted the cover white first to help with the light inside than black over that to help cut down on some of the light coming out from under the tank. Still quite a bit of light coming out so I may take another sheet of acrylic and paint them and add them to the outside of the sump on both side's. Hopefully that will cut down on more light coming out from under the tank. I do have my light's coming on at 12am and going off at 6pm so atleast in the evening when I am home they won't be on.

 

[jake levi]

Re flooding the sump and ATS:

My plan is to have the sump tank divided into 3 sections, the center section with the ATS will have the ATS sitting on a deep gravel bed(aragonite and crushed coral), a pump picks up the water in the return section on the left and brings it over the top to the ATS screen, and then down through the gravel and under a divider to the 3rd chamber from where it will be returned to the tanks. THe ATS and gravel bed have about half the area and the inlet and returns about 25% each. On the inlet side the divider is to the bottom but stops about 2" from the top so water can flow into the gravel bed and on over to the return sump if for some reason the ATS pump is off, ideally with the right sized pumps the total sump should never be more then 40% full with the ATS up and out of it.

 

[Floyd R Turbo]

First of all I'd like to ask a quick question about the xenias. From what I have read here it seems that with an ATS they are a bit of a hit and miss, but I noticed on Floyd's video at the beginning of the thread that his were pulsing like crazy. I'd like to know if they were already pulsing like this before or if anybody noticed that after adding an ATS their xenias became more active ?

As long as you feed adequately, your xenias will live, but with a very powerful scrubber, the N and P are so low that they may not make it. I fragged some out to someone who put them in their tank that was running GFO & Carbon and they turned into goo. After my latest incident with the bad water and subsequent nutrient bloom, they (and the leathers) blew up big time. Since I increased the screen flow and had that huge harvest, they have significantly receded. But I've never had them stop pulsing.

From what I've read today it seems that maybe my dream of a skimmerless tank is not totally unreasonnable after all.

People go skimmerless for the same reason that people use refugiums, DSBs, bare bottom, tons of life rock, bio balls, filter socks, GFO, Carbon, Phosban, etc - there are many ways to set up a system successfully, this is just another tool in the arsenal.

I would like to install 4 screens in inverted V shapes in the surge tank. Each screen would be about 185 square inch (on each face). That would be a total of 740 square inch (per side).

They would be lighted by 3 HO tubes on top, and 2 on the bottom (the surge tank would be acrylic). On each side the tubes would be positioned above the furthest point of the V shape :

The flow from the return pump woud be divided and sprayed on the highest points of the V shape from the top so hopefully the water would flow down along and through the screens.

Your square inches may not be quite enough, lighting from the underside may help boost it, but it's harder to add screen than it is to oversize it.

As far as I know (and I'm no expert on slanted/horizontal screens) once the algae starts to grow thick enough, the water will not penetrate the screen so much as it will just sheet off of it. Most of the water contact on the bottom of the screen will be from filling up the trough the screens are in. This is why you have to double the square inches when you run either slanted or horizontal.

The lights on the underside may help a little, so your idea could work fine. I don't know about how you're going to mount and protect those underside lights, you would have to be diligent to protect them from water. The light source is not perpendicular to the screen, but I don't know how much that will affect the system. Also remember that intensity follows the inverse square rule, and if your surge box needs to fill up X inches above the screen, then your lights have to be X+Y inches above, and that will affect growth. You may be better off building 2 vertical screens in enclosed surge boxes, with lights on either side and one set in the middle, like: lights:screen:lights:screen:lights, with reflectors on the outside set only.

My hope is that the constantly changing level of water in the ATS will alternatively lift the algea strands up and down, thus allowing for better light exposure and hopefully 3d growth while minimizing the boundary flow problems.

...

Does that make any sense to anybody or am I doomed to certain failure?

The concept behind the dump-scrubber is that the water pools until the bucket tips, then the water rushes out past the algae quickly, which is how the boundary layer issue is taken care of. With your design, it's hard to say whether you will achieve the same effect, as the water won't exactly be rushing across the screen, but rather draining out the box quickly from one side. The boundary layer issue centers around the speed of the water passing across the algae/substrate. This is why the dump scrubber and the vertical/waterfall scrubbers work so well. Time will tell if a surge device/scrubber combination is a "best of both worlds" situation, or if it is actually less effective. I would have to say it's a good idea in concept, however a real-world application of this type of arrangement hasn't been tried yet, at least not that I've seen.

If you're going to go ahead with this design, I would plan for possibly needing additional filtration. It may provide total filtration, but then again it may not.

 

[srusso]

The first three attachments would not open? The picture does look brighter, hmmm.

Repost pictures

 

[salty joe]

I run no cooling fans, but neither do most fixtures with remote ballasts. Most 2-lamp fixtures do not run fans either, so I'm not so concerned. Could you post a link to the chart you talk about though? I would be interested to see what you're talking about.

Here ya go. It would be interesting to see at what temp your rig operates.

http://www.lrc.rpi.edu/programs/nlpip/lightingAnswers/lat5/pc10.asp


There's plenty of room for convective cooling of the lamps. As for the heating, with 78 degree water on the other side of the acrylic, whatever temperature increase occurs is wicked away very quickly. So "cooked" is not really accurate, because heat is not the problem. Also, algae doesn't really bleach out due to too much light, it just stops growing after a few hours (photoinhibition). If you look back at some of my posts, you will see that flow rate effects the color of the algae grown. The uneven flow I have in general (because of crosscuts/notches) causes strong green growth in higher flow areas, and lower flow areas are lighter green to yellow.

"Also, algae doesn't really bleach out due to too much light, it just stops growing after a few hours (photoinhibition)."

Which returns me to the bald spots from a too close CFL. If not from too much light, isn't heat all that's left? Do they produce anything besides light and heat?

In my system, I have a drain on each end, so as the algae grows out from the screen and traps the water, it builds up a parabolic shaped water level. I use a slip-to-threaded female/female connector inside the corners, which stick up about 1.5" inside the box (the intent being to create a water trough at the bottom of the screen to reduce bubbles). The top 1" of the flooded area formed by the 3D algae receives good water flow, but then it forms a blockade of sorts that causes relatively stagnant water below that area. Once the growth completely fills the bottom area (below the 'minimum' water line created by the connectors), that water is essentially stagnant, and there isn't much water flow between that stagnant line and the parabolic curve 'trap'. This condition only occurs for a few days, toward the end of the week, but it is enough to choke off much of the algae in that area. I believe this is also due to the fact that the interior width of the screen box is 1.75", and this is probably about as small as anyone has made it. That's less than 1" of space on each side of the screen to the enclosure.

There has been much discussion here and elsewhere about running a fully flooded ATS. At this point, I would not recommend it, and would reserve such a design for experimental purposes only. Personally, my next iteration of design will probably prevent the box from being flooded and restrict 3D growth, at least to the point of blocking lower layers from laminar flow.

If I got this right, when your algae touches the acrylic, you still have the same flow but it now flowing past some algae versus through or over all the algae. Is that agout it?

 

[Coral C's]

Repost pictures
View attachment 143731
View attachment 143732
View attachment 143733
View attachment 143734

I likey that alot! I may borrow that idea from you

 

[srusso]

I likey that alot! I may borrow that idea from you

Yeah took me all of 15 minutes...

 

[Snookster]

Hi Snookster good looking frame very much as I picture mine, is that 3/4" pvc? What size pump/gph?

Yes, 3/4, thanks. It's (pump) some old 500 i had laying around. Doesn't have much head to it,but the flow seems good and it's quiet. Did my first cleaning today. Not much, but there's clearly green growing!

 

[snadaud]

mrbncal, floyd,

Thanks for your answers.

One way that should dramatically increase the horizontal laminar flow (well diagonal really) across the screens when the surge is going would be to simply add a waterproof divider along maybe 3/4 of the length of the screens so that when the level drops the water has to follow the raceway and flow all along the length of both ^ screens like this :

There would still be 3 HO tubes on the top but I hid the center one on the sketchup to better see inside the ats.

According to my previous calculations the flow rate going out when surging would be about 2800 gallons/hour. By making it go through a trough half as wide as previously I think it should yield a linear horizontal speed roughly double from what it was.

The water surface level should be about 1" higher than the top of the screens just before the surge starts and go down all the way to the bottom.

It means that the bottom part would be submerged most of the time, while the top part would mostly get its water from the incomming pipes and only be submerged for 5 or 6 seconds each cycle. I am wondering if it could lead to having a gradient of different types of algae developing from the top to the bottom of the screens according to the local flow type...

Regarding the other types of filtration, I would definitely include a way to add them later if needed but would start only with the ATS and observe the water parameters as I slowly increase the bioload of the tank.

Anyway I am still a few months from starting this and my plans might change until then (though they WILL include and ATS of some kind) but if I end up going with this design I'll make sure to let you know of it works.

Sylvain

 

[Floyd R Turbo]

Here ya go. It would be interesting to see at what temp your rig operates.

http://www.lrc.rpi.edu/programs/nlpi.../lat5/pc10.asp

This chart show operating efficiency with respect to ambient temperature, or the temperature of the surroundings, not the temperature of the lamp. 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. Temperature of the sump area where these lamps operate probably runs into the 85F range with the doors closed, maybe. But measuring the temp of the lamp/fixture and comparing to this chart would not reveal anything significant.

Which returns me to the bald spots from a too close CFL. If not from too much light, isn't heat all that's left? Do they produce anything besides light and heat?

It is from too much light. Intensity is too high, and after 4 hours, the algae stops growing and can reverse growth. So that's 4 hours growth, and 14 hours of inhibition. Heat is not a factor as water is constantly cooling the algae.

If I got this right, when your algae touches the acrylic, you still have the same flow but it now flowing past some algae versus through or over all the algae. Is that agout it?

Water flows through the part of the algae that is in contact with the screen at the highest point, then it starts to deflect toward the drain. As you get lower/deeper in the flooded area, the more water is trapped and stagnant

 

[jake levi]

lamps and 3/4 " frame

lamps and 3/4 " frame

I also will try that with the lights, I ordered the two pcs of acrylic for the two dividers in the stock tank/filter/sump and will be putting it together next week.

I am going to use snooksters 3/4 " pvc frame for the ATS,standing on top of the aragonite gravel in the center section of the filter,

what did you cut the 1/8" slot in it with? I am going to use a maxi jet 900 in it at first to take the water out of the inlet sump to the ATS for the first stage, but when the system is at full amount of tanks will use the maxi 3000.

I've got a lot to do the next two weeks on this but really looking forward to it.

Thanks guys, :beer:

 

[Mikei70]

I haven't read the entire thread so forgive me if this has been previously addressed--

Is there any kind of 'low-tide' smell associated with the scrubber? I ask because I have a small amount of algae that grows on the return and the back glass near the very top of the tank. I definitely notice an odor when the water level drops enough to expose the algae during a water change.

 

[snadaud]

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