Algae Scrubber Basics
- Thread starter srusso
- Start date
Floyd R Turbo
Either busy or sleeping
Here's a few pics on my Photobucket page. I drew it all up in CAD and my Dad and I fabricated it.
http://s611.photobucket.com/albums/tt191/FloydRTurbo/Customer SW Aquarium/2010-11-19 ATS 2/
It's designed to that you can lift up on the inner box and slide it out. You could probably make the outside enclosure with an end that you can remove so that it holds the lights in place when in use, but allow you to slide the box out. You will still need a bulkhead or some kind to allow the water to leave the inner box without getting all over the outer box. Someone else posted a build where they just let bulkheads drain into a large PVC pipe, so there was no connection between the inner box and the drain system. I just inserted PVC pipes into the 'drains' and had to remove them each time to get the box out. That was a pain.
I would make the inner box wide enough to allow for a 1" bulkhead (which has a 2.67"+ diameter flange, which you could trim down on 2 edges if you wanted it narrower - I did that on Rev 1).
As far as building it, you're talking acrylic fabrication. That's a whole other thread...
http://www.reefcentral.com/forums/showthread.php?t=1056956
9+ years of info, 2 splits, 5300 posts.
http://s611.photobucket.com/albums/tt191/FloydRTurbo/Customer SW Aquarium/2010-11-19 ATS 2/
It's designed to that you can lift up on the inner box and slide it out. You could probably make the outside enclosure with an end that you can remove so that it holds the lights in place when in use, but allow you to slide the box out. You will still need a bulkhead or some kind to allow the water to leave the inner box without getting all over the outer box. Someone else posted a build where they just let bulkheads drain into a large PVC pipe, so there was no connection between the inner box and the drain system. I just inserted PVC pipes into the 'drains' and had to remove them each time to get the box out. That was a pain.
I would make the inner box wide enough to allow for a 1" bulkhead (which has a 2.67"+ diameter flange, which you could trim down on 2 edges if you wanted it narrower - I did that on Rev 1).
As far as building it, you're talking acrylic fabrication. That's a whole other thread...
http://www.reefcentral.com/forums/showthread.php?t=1056956
9+ years of info, 2 splits, 5300 posts.
Floyd R Turbo
Either busy or sleeping
20" wide and about 7" tall
Floyd R Turbo
Either busy or sleeping
Timer's been on its regular schedule as have my cleanings (every 7 days). Scrubber is about 10 weeks old. Almost time to change bulbs, but not quite... although I could try that first. It's about 11" wide and 12" long, fed by my return pump (Eheim 1262) and lit by a pair of CFLs on both sides. Here's a photo from about a month ago:
Growth was green back then (lighter than the photo). Now it appears more brown and stringy; hence my concern about dinos continuing on the screen. I'll try to grab a photo before I clean it up.
If you're ever in the neighborhood, definitely happy to have you over to check things out in person!
I have an answer for your issue. You have likely getting dinos because your relfectors are only covering 1/3 of your screen. You have 1/3 the filtering that you think you have, which leave nutrients in the water for the dino's to grow. And since the nutrients in the water stay high, the screen stays brown. Blacking out the tank will just make this worse because the dino's that die in the display will put even more nutrients into the water, and make the screen stay brown.
The fix is to not to black out the display; get reflectors that cover the whole screen; and probably increase wattage until you start growing yellow, then cut an hour or two of light (more watts with less hours, is always better that more hours with less light).
SPotter
Active member
has there been any feedback on what works better with the dimension on the screen...like the wider the screen the better?
Floyd R Turbo
Either busy or sleeping
I don't know that there is that much of a difference until you get above about 20-24" tall. At that point, you tend to start approaching a diminishing return point, because the long strands of algae block more light on the lower section of the screen. If you wanted to build a box that allowed 3D growth this might help, but it would have to be a very sturdy pressure vessel, well braced, and thick (like 3/8", and a good cell cast acrylic, like Plex-G or Polycast).
Flow rate would be different for different orientations but filtration capacity would be the same since a wider screen allows more water to pass but taller allows a longer pass so it pretty much evens out.
Probably a little more benefit to the wider screen.
Flow rate would be different for different orientations but filtration capacity would be the same since a wider screen allows more water to pass but taller allows a longer pass so it pretty much evens out.
Probably a little more benefit to the wider screen.
MrClean
Active member
I don't have a pic of the sump, but the problems are legion. A too tall sump in a short cabinet so I really have trouble getting things in and out of it; removing the skimmer cup is a challenge and that is just a lift and move to the side. The sump is chopped into smallish compartments but it has a long area along the back, ~20x7.
I really didn't want to re-plumb, cut the compartments out, or source a new sump, so the ATS will have to go along the back. I like the separate box, but it would be difficult to undo a union.
Oh well, I've put up with that sump for a long time, maybe it's time to replace it.
I really didn't want to re-plumb, cut the compartments out, or source a new sump, so the ATS will have to go along the back. I like the separate box, but it would be difficult to undo a union.
Oh well, I've put up with that sump for a long time, maybe it's time to replace it.
Floyd R Turbo
Either busy or sleeping
What about a totally enclosed system that sits outside the sump and drains into a low area? It would be more difficult and more expensive to build, and you wouldn't have to tear everything up.
Floyd R Turbo
Either busy or sleeping
I remember your post from before - can you provide more info about your system, there might be something else going on. Screen size, flow rate/inch of screen, N and P levels, livestock (fish & corals), tank lighting, etc. Everything you can think of. And pictures of your tank and scrubber are the most helpful...
I posted on here a few days ago about adding some pictures and I have some updates. I've been fighting algae coming and going and decided to build my own ATS. It might look a lot like srusso's because I wanted to try and mimic his design since it works so well. So with a trip to Lowes, actually about 4 trips in all and about a days worth of work, I have it up and running.
Here's the setup, I picked up 4 23W 2700K CFL's.
Another Shot
Here's the setup, I picked up 4 23W 2700K CFL's.
Another Shot
Floyd R Turbo
Either busy or sleeping
you need to add relfective material to those shop lights, it will dramatically increase your scrubber's effectiveness. If you look in the summary 2001-2010 posts, you can see a pic of his showing the comparison.
Other that than, looks good! Lots of light for a screen that size, which is always better than not enough, as long as your flow is adequate.
Other that than, looks good! Lots of light for a screen that size, which is always better than not enough, as long as your flow is adequate.
OodleyBoodely
New member
"General Electric Soft White 100" (any brand in this range of actual wats and kelvin will work) These are the 100w equivilent but only 26wat actual spiral compact lamps. You want the Soft or Warm whites which are in the 2200 to 2700 Kelvin range. Change bulbs every 3 months because the spectrum will shift after that and they will not grow algae as well.
Floyd R Turbo
Either busy or sleeping
It likely has zero to do with brand and model of lamp.
From reading back through your posts, it sounds like you have running 2 26W lamps in dome-type reflectors, a 10 inch wide screen, light bio-load, but you still have some type of alge in the display.
If I had to take a stab at this, I would say that your light is too weak, and possibly your reflectors are not big enough. You posted that your screen is 10 inches wide but how tall is it? I'm guessing it's 9-10 tall also. You need 90-100 watts of light or more for that setup. The weaker light will grow darker algae which has less filtering power.
You need to get a couple of 42W CFLs and big (10") dome reflectors, and make sure that the lamp doesn't extend past the dome, or you lose that light. Then place those 4"-5" away from the screen and run them for 9-12 hours a day instead of 18. Increase the photoperiod a little each week until you start to get yellow algae instead of green, then back it off.
It is better to go with stronger light for a shorter period of time, as more intense light will grow greener algae, but this is limited by flow rate. Yellow algae is the result of light that is so intense that the algae can't get nutrients in and out fast enough. Brown algae is just not enough light. You don't have enough light.
Floyd R Turbo
Either busy or sleeping
There is another option here. I am working on a post to describe sizing a screen based on the amount you feed. This is a relatively new 'guideline' and I want to explain it properly in that post, which will be coming here shortly.
You don't feed very much, so your screen is capable of handling a lot more nutrients than you supply to the system. Thus you are spreading the filtration over a wider, less adequately lit area. If you are cramped for space, then cut your screen down to more match your lamp and reflector signature. This will concentrate the algae growth only where the light is actively performing filtration. It will also increase flow per inch to the screen. So you will deliver the same amount of nutrient to the algae, but in a space that is more concentrated, has more intense light (this would be using the same lights you currently have) and more flow.
Keep in mind that this is all not really that much of a concern if you have low N and P, and your tank is free of nuisance algae. It sounds like you are wanting to grow green algae for the sake of just wanting it to be green. Or is there something else I'm missing?
You don't feed very much, so your screen is capable of handling a lot more nutrients than you supply to the system. Thus you are spreading the filtration over a wider, less adequately lit area. If you are cramped for space, then cut your screen down to more match your lamp and reflector signature. This will concentrate the algae growth only where the light is actively performing filtration. It will also increase flow per inch to the screen. So you will deliver the same amount of nutrient to the algae, but in a space that is more concentrated, has more intense light (this would be using the same lights you currently have) and more flow.
Keep in mind that this is all not really that much of a concern if you have low N and P, and your tank is free of nuisance algae. It sounds like you are wanting to grow green algae for the sake of just wanting it to be green. Or is there something else I'm missing?
Floyd R Turbo
Either busy or sleeping
I think I'm going to start piecing out the "Part 2" of the summary, and then just put it all together whenever there's enough there to warrant it. It's too much to wait for...
Floyd R Turbo
Either busy or sleeping
New screen sizing guideline
After much experimentation and observation, there is a new guideline that can be followed for sizing your scrubber screen. Instead of sizing the screen based on the size of the display tank or system water volume, you can size the screen based on how much you feed the tank. This actually makes a lot of sense if you think about it, because the nutrient load is directly proportional to the amount of food you add to the tank.
Here's the guideline:
Each cube of frozen food you feed per day needs 12 square inches of screen, with a light on both sides totaling 12 watts. So if you feed 1 cube of food per day, then a 3x4 screen with a 6 watt lamp on each side (actual, not equivalent) will adequately filter the system. If you have a larger tank and you feed 10 cubes per day, you would need a 120 square inch screen with 120 total watts, or 60 watts per side (again, actual wattage).
If you feed flake food, feeder fish, etc, then you need blend it up super-thick, strain out the excess water, pour it into a cube, and see how many cubes that comes to. For Nori, 8 square inches is equivalent to 1 cube.
Just so you know, I run a screen that is about 120 square inches with 4 24W T5HOs and really good reflectors, and I feed my tank roughly 6-8 cubes per day or a DIY food, and grow a ton of green algae, and I have zero waste buildup anywhere in the tank. So this really is a pretty accurate way of sizing your system.
Now, I realize that there are a lot of people who have already built systems that are looking at this now and thinking that their scrubber is way too big. Feeding 10-12 cubes per day to a 100 gallon system is a lot of food, and costs a lot of money, so in reality, most people aren't doing this. Unless you're like me, and feed a total tank food that costs $10 for a bag that is roughly 2x as big as a bag of Rod's Food, it costs way too much.
Having an oversized scrubber is not a bad thing, as long as there is enough light and flow. IMO, a larger scrubber is better, as long as the flow and lighting are good, because it can more adequately handle variances in the system such as overfeeding, or an organism death that cannot be removed (or is not even known about), addition of new corals, fish or inverts, or an outbreak of algae, cyano, dinos, etc. It also allows you to maximize the use of your system, meaning you can pack it with corals and fish and feed them all they can physically eat. A large scrubber, sized as has been recommended up until now, is a very robust and forgiving filtration system.
Sizing a scrubber based on quantity and frequency of feeding means that the quantity and size of livestock in the system must be limited. That being said, most people are used to feeding sparingly, as little as every other day or maybe every 3rd day, so minimal feedings are where they are at and where they plan to stay. So if you build a feeding-scaled scrubber, you just have to be aware of the limitations of that system.
Now that this option exists, it releases many other possibilities for new builds, and solutions for existing problems. This is potentially good news for many out there trying to fix issues such as flow rate due to plumbing and pump restrictions or space restrictions preventing adequate lighting.
If you have a screen that doesn't have enough flow (less than 35 GPH/in of screen width) and you don't have any way to increase the flow short of a total or partial tear-down, then just shorten the screen.
If you don't have the space for additional light fixtures, don't sweat it. Just realize the limitation of your system. Ideally though, you do want the screen to match the size of the area that is fully illuminated, as that area is really getting the effective growth. Or at least, you only want to consider the area that is adequately illuminated as being your effective filter size. If your scrubber is inadequately lit and you are experiencing issues, consider increasing the lamp wattage and adjusting the photoperiod (discussed in the next update)
If you aren't getting thick green growth, it is most likely because you don't have enough flow, don't have enough light, you're not feeding enough, or a combination of those factors. Green growth does the best filtering, so that is what you want. If you keep the same lighting and flow, then reduce the width of the screen, you bring the same amount of nutrients to a more compact area of algae growth which receives more intense light.
Next subject: Over-lighting your screen
After much experimentation and observation, there is a new guideline that can be followed for sizing your scrubber screen. Instead of sizing the screen based on the size of the display tank or system water volume, you can size the screen based on how much you feed the tank. This actually makes a lot of sense if you think about it, because the nutrient load is directly proportional to the amount of food you add to the tank.
Here's the guideline:
Each cube of frozen food you feed per day needs 12 square inches of screen, with a light on both sides totaling 12 watts. So if you feed 1 cube of food per day, then a 3x4 screen with a 6 watt lamp on each side (actual, not equivalent) will adequately filter the system. If you have a larger tank and you feed 10 cubes per day, you would need a 120 square inch screen with 120 total watts, or 60 watts per side (again, actual wattage).
If you feed flake food, feeder fish, etc, then you need blend it up super-thick, strain out the excess water, pour it into a cube, and see how many cubes that comes to. For Nori, 8 square inches is equivalent to 1 cube.
Just so you know, I run a screen that is about 120 square inches with 4 24W T5HOs and really good reflectors, and I feed my tank roughly 6-8 cubes per day or a DIY food, and grow a ton of green algae, and I have zero waste buildup anywhere in the tank. So this really is a pretty accurate way of sizing your system.
Now, I realize that there are a lot of people who have already built systems that are looking at this now and thinking that their scrubber is way too big. Feeding 10-12 cubes per day to a 100 gallon system is a lot of food, and costs a lot of money, so in reality, most people aren't doing this. Unless you're like me, and feed a total tank food that costs $10 for a bag that is roughly 2x as big as a bag of Rod's Food, it costs way too much.
Having an oversized scrubber is not a bad thing, as long as there is enough light and flow. IMO, a larger scrubber is better, as long as the flow and lighting are good, because it can more adequately handle variances in the system such as overfeeding, or an organism death that cannot be removed (or is not even known about), addition of new corals, fish or inverts, or an outbreak of algae, cyano, dinos, etc. It also allows you to maximize the use of your system, meaning you can pack it with corals and fish and feed them all they can physically eat. A large scrubber, sized as has been recommended up until now, is a very robust and forgiving filtration system.
Sizing a scrubber based on quantity and frequency of feeding means that the quantity and size of livestock in the system must be limited. That being said, most people are used to feeding sparingly, as little as every other day or maybe every 3rd day, so minimal feedings are where they are at and where they plan to stay. So if you build a feeding-scaled scrubber, you just have to be aware of the limitations of that system.
Now that this option exists, it releases many other possibilities for new builds, and solutions for existing problems. This is potentially good news for many out there trying to fix issues such as flow rate due to plumbing and pump restrictions or space restrictions preventing adequate lighting.
If you have a screen that doesn't have enough flow (less than 35 GPH/in of screen width) and you don't have any way to increase the flow short of a total or partial tear-down, then just shorten the screen.
If you don't have the space for additional light fixtures, don't sweat it. Just realize the limitation of your system. Ideally though, you do want the screen to match the size of the area that is fully illuminated, as that area is really getting the effective growth. Or at least, you only want to consider the area that is adequately illuminated as being your effective filter size. If your scrubber is inadequately lit and you are experiencing issues, consider increasing the lamp wattage and adjusting the photoperiod (discussed in the next update)
If you aren't getting thick green growth, it is most likely because you don't have enough flow, don't have enough light, you're not feeding enough, or a combination of those factors. Green growth does the best filtering, so that is what you want. If you keep the same lighting and flow, then reduce the width of the screen, you bring the same amount of nutrients to a more compact area of algae growth which receives more intense light.
Next subject: Over-lighting your screen
Floyd R Turbo
Either busy or sleeping
Strong vs weak lighting
The general recommendation for lighting strength and period is 1 watt per square inch of screen / per gallon of tank size. So a 10x10 screen for a 100 gallon tank would need 100 watts of lighting. However, your setup might not be conducive to achieving this ‘ideal ratio’. There are times when you can nudge this rule around, and there are limitations to how far you can nudge it. You just have to pay attention to your system and your growth.
If you are designing your system and are “in between” 2 lamp strengths, choose the stronger lamp. So if you are setting up a 40 gallon filter and can choose between an 18W or 23W CFL on each side, go with 23W. If you start to get yellow or rubbery algae (‘burnt’ algae), then increase the flow, add iron, or decrease the light period (in that order of preference).
You want as much flow as possible, because this brings nutrients to the algae. You want as rough of a screen as possible so that you can have as much flow as possible without the algae detaching. You want as much light as possible, because stronger lighting grows greener, brighter algae, which does the most filtering, and stronger light also helps prevent the algae from detaching.
If you start getting yellow, rubberly algae, that is a symptom of not providing enough nutrients to the screen in relation to the amount of light the algae is getting. Logically, if you can’t increase flow, you would think that you would instead change to weaker lamps and run then longer. This is NOT what you want to do. Weaker light will grow darker algae, which does not filter as effectively. You want lots of physical algae growth, which needs more intense lighting, not longer lighting. You would therefore run a shorter, more intense photoperiod.
Finding the balance point between the photoperiod and avoiding the yellow growth is the key. This is something that will differ with every system, so you just have to pay attention and make photoperiod adjustments as needed.
So now that I’ve brought up the shorter, more intense photoperiod, let’s discuss another topic.
The following has been suggested as an experimental fix for brown/black algae growth (from a high nutrient system), and also for extending the life of the bulbs past 3 months:
1. Use bulbs with twice the wattage as recommended; so use 2 watts per square inch of screen. Thus a screen 10 X 10 inches = 100 square inches would get 200 total watts of light instead of 100 watts
2. Run the lights for half as many hours as recommended; this would be 9 hours instead of 18.
3. Around 3 months, when the growth starts to get darker (because the bulbs are getting weaker), start increasing hours until it grows green again. When you reach 18 hours, it's time for new bulbs
This does a few things: The first is obvious; you will get longer bulb life as long as you remember to increase the hours when you get to 3 months. Second, if the light is strong enough, it can also turn black/brown growth into green, no matter how high the nutrients are. The trick is just to not burn the algae; thus the hours have to be less
As you can see, this is related to the above topic regarding flow, lighting intensity, and the previously posted “New Screen Sizing Guideline”. This is not a completely new notion, temporarily powering through “black slime” algae with more intense light has been done. Doing it on a regular basis is not something that has been done very much. Keeping good records of photoperiods and screen growth would be advisable.
The keys to making this type of scrubber setup work are knowing your system and paying attention to your growth, and making modifications as necessary.
The general recommendation for lighting strength and period is 1 watt per square inch of screen / per gallon of tank size. So a 10x10 screen for a 100 gallon tank would need 100 watts of lighting. However, your setup might not be conducive to achieving this ‘ideal ratio’. There are times when you can nudge this rule around, and there are limitations to how far you can nudge it. You just have to pay attention to your system and your growth.
If you are designing your system and are “in between” 2 lamp strengths, choose the stronger lamp. So if you are setting up a 40 gallon filter and can choose between an 18W or 23W CFL on each side, go with 23W. If you start to get yellow or rubbery algae (‘burnt’ algae), then increase the flow, add iron, or decrease the light period (in that order of preference).
You want as much flow as possible, because this brings nutrients to the algae. You want as rough of a screen as possible so that you can have as much flow as possible without the algae detaching. You want as much light as possible, because stronger lighting grows greener, brighter algae, which does the most filtering, and stronger light also helps prevent the algae from detaching.
If you start getting yellow, rubberly algae, that is a symptom of not providing enough nutrients to the screen in relation to the amount of light the algae is getting. Logically, if you can’t increase flow, you would think that you would instead change to weaker lamps and run then longer. This is NOT what you want to do. Weaker light will grow darker algae, which does not filter as effectively. You want lots of physical algae growth, which needs more intense lighting, not longer lighting. You would therefore run a shorter, more intense photoperiod.
Finding the balance point between the photoperiod and avoiding the yellow growth is the key. This is something that will differ with every system, so you just have to pay attention and make photoperiod adjustments as needed.
So now that I’ve brought up the shorter, more intense photoperiod, let’s discuss another topic.
The following has been suggested as an experimental fix for brown/black algae growth (from a high nutrient system), and also for extending the life of the bulbs past 3 months:
1. Use bulbs with twice the wattage as recommended; so use 2 watts per square inch of screen. Thus a screen 10 X 10 inches = 100 square inches would get 200 total watts of light instead of 100 watts
2. Run the lights for half as many hours as recommended; this would be 9 hours instead of 18.
3. Around 3 months, when the growth starts to get darker (because the bulbs are getting weaker), start increasing hours until it grows green again. When you reach 18 hours, it's time for new bulbs
This does a few things: The first is obvious; you will get longer bulb life as long as you remember to increase the hours when you get to 3 months. Second, if the light is strong enough, it can also turn black/brown growth into green, no matter how high the nutrients are. The trick is just to not burn the algae; thus the hours have to be less
As you can see, this is related to the above topic regarding flow, lighting intensity, and the previously posted “New Screen Sizing Guideline”. This is not a completely new notion, temporarily powering through “black slime” algae with more intense light has been done. Doing it on a regular basis is not something that has been done very much. Keeping good records of photoperiods and screen growth would be advisable.
The keys to making this type of scrubber setup work are knowing your system and paying attention to your growth, and making modifications as necessary.
Floyd R Turbo
Either busy or sleeping
Ok, so how do you know your flow is 400 GPH? Did you measure it or calculate it?
Read my last couple posts and see if that sounds like something you might be able to try.
I would start by leaving the screen alone and going to 42W lamps and knocking back the photoperiod. Green algae filters better, which is going to help you battle what sounds like either GHA in the tank or green cyano. Either way, you need a strong scrubber to get rid of it, and don't black out your tank like the 'standard' advice says, that will just result in dumping nutrients into the system and you'll get darker (less efficient) algae growth.
flyhigh123
funky member
I love 99 cents store!
So, I dropped by today, building my ats, I found 40w compact fluorescent bulbs that are a 150w equivalent, for 59 cents each! These were $8+ each at homedepot!
Also found 23w=100w cf bulbs for 59 cents as well which were 2 for 6 at homedepot.
It's rare to find the 40watts.
Also, got a nice pair of aquarium tongs for a dollar good for picking up small things.
I'm in Cali btw, so it's subsidized I think
So, I dropped by today, building my ats, I found 40w compact fluorescent bulbs that are a 150w equivalent, for 59 cents each! These were $8+ each at homedepot!
Also found 23w=100w cf bulbs for 59 cents as well which were 2 for 6 at homedepot.
It's rare to find the 40watts.
Also, got a nice pair of aquarium tongs for a dollar good for picking up small things.
I'm in Cali btw, so it's subsidized I think
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