Algae Scrubber Basics

[Floyd R Turbo]

I don't know that one always has to do with the other, so you might be looking at this from the wrong angle.

You don't really want to "feed" the scrubber by adding food to the tank. I don't subscribe to that mindset - you should not have to "force" a scrubber to grow properly like this. Adding iron can help, but for the most part that is not long-term sustainable, and I have never really had to do that myself

So let's take a step back and look at the big picture:

How big is your tank?
How many fish / what size?
Scrubber size: 6x5 check
Lights: CFL
What wattage?
How long do you run them?
How close are they?
Orientation of lamps?
Reflector?
Flow rate of water across screen? <-- total flow

Pics would help as well, might be something said there that is not easily explained or clear with just text/words

 

[zachtos]

Algae turf scrubber setup on one of the overflows. This is a pain in the ***. I can't get the flow figured out to keep it even sheet of water. It also sounds like a bath tub filling up. The tank is nearly silent without this. I am not sure what I will do anymore, I do not like the noise.

 

[Floyd R Turbo]

Initially, trying to get even flow it fruitless. You need to allow the screen to "slime up" a bit. Dial the flow back until you have just enough flow for even coverage, and leave it that way until you have growth that is thick enough to obscure the mesh pattern. At that point, you can probably bump up the flow, but until then, massive flow is only going to result in arcing and uneven growth. I can see arcing in that pic.

For the noise, well...the bottom of the screen looks like it's about 1-2" off the water surface, so you are going to have noise. For an open-air screen, you need to extend that screen down to the water surface or maybe an inch below it. You can do this by just zip-tying another section of screen to the bottom of your current one (instead of making a whole new screen). That will silence it.

 

[zachtos]

Initially, trying to get even flow it fruitless. You need to allow the screen to "slime up" a bit. Dial the flow back until you have just enough flow for even coverage, and leave it that way until you have growth that is thick enough to obscure the mesh pattern. At that point, you can probably bump up the flow, but until then, massive flow is only going to result in arcing and uneven growth. I can see arcing in that pic.

For the noise, well...the bottom of the screen looks like it's about 1-2" off the water surface, so you are going to have noise. For an open-air screen, you need to extend that screen down to the water surface or maybe an inch below it. You can do this by just zip-tying another section of screen to the bottom of your current one (instead of making a whole new screen). That will silence it.

I will try to extend the screen length. Yes I notice it is hard to keep even flow right now. I am not really able to adjust flow directly, it's on a return. I can move the flow up/down w/ my DCS jebao pumps but it does affect my sump level since the display rises.

It's actually touching water on right side but not left. It's not level. I found that the flow wants to shoot out at an angle from the return fed pipe. Not sure how to make it want to flow straight down. I may give up and try the spray bar option on both sides. Maybe better for my application? The pipe is not glued, so I can swap back and forth for now.

 

[Optimus_Prime]

Algae turf scrubber setup on one of the overflows. This is a pain in the ***. I can't get the flow figured out to keep it even sheet of water. It also sounds like a bath tub filling up. The tank is nearly silent without this. I am not sure what I will do anymore, I do not like the noise.

I'm no an expert but wouldn't it be better to have the top of the screen partially inside the pic pipe through a slit? That's how I have mine and I have zero issues with even water flow throughout the whole screen. Eventually, obviously, when algae starts to grow towards the top, it'll start to squirt water but that's easily fixed by just scraping the top part where the algae is growing.

Drop the whole contraption so the screen is just below the water surface...BAM...silent!

Hope that helps some.


Sent from my HTC6525LVW using Tapatalk

 

[zachtos]

I'm no an expert but wouldn't it be better to have the top of the screen partially inside the pic pipe through a slit? That's how I have mine and I have zero issues with even water flow throughout the whole screen. Eventually, obviously, when algae starts to grow towards the top, it'll start to squirt water but that's easily fixed by just scraping the top part where the algae is growing.

Drop the whole contraption so the screen is just below the water surface...BAM...silent!

Hope that helps some.


Sent from my HTC6525LVW using Tapatalk

Screen actually is about 1/4" inside the slot, and the slot itself is 3 slots each about 1/4" wide, I needed big because of the flow on return so high. Estimate 1200gph maybe. Need to measure it I guess. I tried a simple duct tape light blocker on the top part.

Also, I have a rogue stream on the end that wants to shoot past the screen sometimes, goes away when I tone back the flow and/or angle the pipe to not be level and slide to the right more.

 

[zachtos]

I tried building a spray bar last night, I did not like it at all. It does give more even stream, but with my high flow, I had a hard time keeping the streams from splattering through the grid. Seemed to actually create more splashing, but less noise. Within a few minutes I realized that the holes would plug up too fast (even at 1/4") to be safe as a return option. I did modify my screen and make it longer/wider so any rogue streams from the slot pipe would always hit screen, even if the edge is mostly dry. It did help and it is more tolerable, thought I will probably need to figure out how to get more even flow from the slot. I do have the screen inserted about 1/8" into the slot. Perhaps 1/4" wide slot is too wide for 1200gph at 18" ?

 

[Floyd R Turbo]

Well I just spent half an hour scanning 100+ pages of this thread looking for a specific example of something that I thought might work for you but I couldn't find it.

Essentially, you have way more flow than you would need, and this is kind of a special case where you can do something a bit different.

So what you do is make your slot the standard 1/8" for the entire length, maybe a bit more, it's not really relevant. The difference is, on the far end of the slot pipe, instead of capping it off, you turn it down to the sump. Actually what I would do is take a tee fitting and install that on the end. Make it one where the side outlet matches your slot pipe diameter, but the main part of the tee is much larger. So maybe, a 1.5" tee with a 3/4" side outlet.

Install the main tee vertical. The top acts as a vent to prevent siphoning (if you did just an elbow down, that would tend to siphon and you would get no flow on the screen - trust me on that). Add a short length of pipe (maybe 6-12") to the top to inhibit splashing, or add a strainer, etc. Extend the bottom side down to the sump, at or below water level, not sure which would be better.

What this does is allows for the flow out of the slot to self-regulate to an extent. You won't be forcing flow (which causes streamers). The excess just passes right by the screen and goes into the sump.

The caveat here is that you absolutely much use a light blocker, or else the slot will quickly clog up with growth. Also, you must absolutely leave the section of screen that is inserted into the slot pipe (and about 2 additional rows) unroughed. This, in combination with the light blocker, will keep your flow pretty much constant throughout the growth cycle, and you won't have any streamers, and probably not any spray either.

You don't need the blockers at first, you should be able to try this out and verify that it works for now...hope that helps, not sure why I didn't think of it sooner.

 

[JZinCO]

I had the same issue (with too much flow) and just added 2 parallel meshes from the same pipe. I don't think I will get 3x more algae growth but I don't think I will get <1x versus a single mesh.

 

[zachtos]

Well I just spent half an hour scanning 100+ pages of this thread looking for a specific example of something that I thought might work for you but I couldn't find it.

Essentially, you have way more flow than you would need, and this is kind of a special case where you can do something a bit different.

So what you do is make your slot the standard 1/8" for the entire length, maybe a bit more, it's not really relevant. The difference is, on the far end of the slot pipe, instead of capping it off, you turn it down to the sump. Actually what I would do is take a tee fitting and install that on the end. Make it one where the side outlet matches your slot pipe diameter, but the main part of the tee is much larger. So maybe, a 1.5" tee with a 3/4" side outlet.

Install the main tee vertical. The top acts as a vent to prevent siphoning (if you did just an elbow down, that would tend to siphon and you would get no flow on the screen - trust me on that). Add a short length of pipe (maybe 6-12") to the top to inhibit splashing, or add a strainer, etc. Extend the bottom side down to the sump, at or below water level, not sure which would be better.

What this does is allows for the flow out of the slot to self-regulate to an extent. You won't be forcing flow (which causes streamers). The excess just passes right by the screen and goes into the sump.

The caveat here is that you absolutely much use a light blocker, or else the slot will quickly clog up with growth. Also, you must absolutely leave the section of screen that is inserted into the slot pipe (and about 2 additional rows) unroughed. This, in combination with the light blocker, will keep your flow pretty much constant throughout the growth cycle, and you won't have any streamers, and probably not any spray either.

You don't need the blockers at first, you should be able to try this out and verify that it works for now...hope that helps, not sure why I didn't think of it sooner.

Thanks, that is a good idea. I will try this weekend and post photo results I hope. I did not glue the spray/slot bar so this is easy to reconfigure anytime. The hard part will be measuring the gph from the long curtain I think to be sure. (also will try the 2x back to back mesh to see if help as quick fix, but rather just 1 screen).

I do wonder if I will have to adjust the slot size past 1/8" to make sure excess flow does not just bypass, as it is similar to electricity, water will choose the path of least resistance for the majority of flow. OR perhaps just change the downspout/bypass end pipe to lower diameter bushing down to get more flow through the slot.

*come to think of it, I may just be able to throw the TEE on the end of my existing 1/4" slot pipe and see what happens, probably will still need to reduce the slot size though.

What is the most popular easy to acquire material we are using for light blocking? (I got those zip tie beads at menards in the electrical section)

 

[Floyd R Turbo]

you could do an up 90, then a length of pipe, then a 90 to horizontal, then into the tee. That would promote some pressure at the pipe but allow bypass (same tee from that horizontal point on)

 

[Chris Abbott]

Just keep working on different configurations until you get the combo you need. I will say making the slot wider was never a solution that worked for me. Overflow fed ats is very possible and worked very well for me once i got it dialed in.

 

[davidgnome]

attached video

attached video

I don't know that one always has to do with the other, so you might be looking at this from the wrong angle.

You don't really want to "feed" the scrubber by adding food to the tank. I don't subscribe to that mindset - you should not have to "force" a scrubber to grow properly like this. Adding iron can help, but for the most part that is not long-term sustainable, and I have never really had to do that myself

So let's take a step back and look at the big picture:

How big is your tank?
How many fish / what size?
Scrubber size: 6x5 check
Lights: CFL
What wattage?
How long do you run them?
How close are they?
Orientation of lamps?
Reflector?
Flow rate of water across screen? <-- total flow

Pics would help as well, might be something said there that is not easily explained or clear with just text/words

Tank:120 gallon with 40 breeder sump, running gfo, and skimmer as well as the ATS

Fish: 10 total, Longnose butterfly medium sized 4", 2 leopard wrasses small to medium, 6 blue green chromis small to medium, 1 starry blenny medium 3"

CFL: 23 watts x 2

Time: I had been doing 18 hours on, 6 off. BUT have changed to 15 on, 8 off. Reason being I had yellow algae and was advised to maybe down the photo period. I also turned down my DT take lights from 12 hours to 10 hours.

Reflector type and orientation: One is pointed directly at the screen about 4" away, the other is slightly angled and is about 3" at the top of the screen and 4.5" nearing the bottom of the screen.
Reflector type is a alluminum dome from lowes, with a clamp.

Flow rate: I would guess its above 35gph per 6 inches as the flow is pretty quick across the screen. Since the video attached I have a good bit more of growth this last week, no algae per see but it is a thicker yellowish almost green color.

I actually have a video, but will need to use a different computer to upload it.

 

[biglurr54]

I have a 2 cube a day waterfall scrubber. I have some algae growth in my tank and my growth on the scrubber isn't great. The whole system is 8 months old and the scrubber has been running since day one. My current set up is a 4" x 6.5" screen in a slotted PVC pipe. I build an acrylic box to hold it. It runs off my return line so GPH is tough to say. For lighting I have 4 3watt 660nm deep red Leds and 1 3 watt RB led per side running at 700ma. That is a total of 8 660nm and 2 RB leds running at 700ma.



I feel that my issues are either GPH flow or lighting. My return pump is a rio 3100 and it is a direct shot from the sump to the tank. I have tried 100% going through the scrubber and it was way too much flow. It was like a garden hose just spraying out the slot. I have about half the return water running through the scrubber at this point. It keeps the whole screen covered is a steady stream of water.



Would I be better off replacing the RB leds with 660s or redesign the lights and add 10:1 Red:RB 1watt leds preside?



When I clean the scrubber I have mushy green algae on it but nothing that really attaches or pulls off the scrubber. All I get off the scrubber is green water with no physical algae.



Let me know your thoughts.


Sent from my SM-N910V using Tapatalk

 

[Floyd R Turbo]

Got a pic of the scrubber and/or what the growth looks like?

 

[biglurr54]

Sent from my SM-N910V using Tapatalk

 

[biglurr54]

I'll take a pic of the growth today when I get home. It looks like good growth but is just slimy water when cleaned off.

Sent from my SM-N910V using Tapatalk

 

[Floyd R Turbo]

How much are you feeding?

looks like the LEDs could be really close. Is there a way you can parallel the 2 arrays together to cut the intensity in half? Also the RB at 700mA can easily cause photosaturation. You might try jumpering over that one temporarily and seeing if that makes a difference.

 

[ratherbeflyen]

without seeing it, my first thought is your screen needs to be rougher.

 

[biglurr54]

So the leds are on a dimmer. And it's turned all the way up. I can dial it back down if needed. The rb has to be on unless I replace them with red to keep the forward voltage high enough.

The screen was rough but seems to be getting less and less rough as it is in use and being cleaned.

Should I re rough it up? One side at a time? The leds are spaced out fairly well. One on each corner of the heat sinks and the rb in the middle.

Sent from my SM-N910V using Tapatalk