Algae Scrubber Basics

[JohnnyB in SD]

The MD7 should be more than enough and maybe overkill. If it were me I would get an MD5 (49w) or the 7 and probably valve it down if I thought I might need to have higher flow for some future possibilities.
I bought one of those marineland submersible type pumps once. Not impressed with the quality, seems more like a toy than a hobby pump. It cr@pped out prematurely too.

 

[EnderG60]

Well in that case, if you rigged up something with a break in between, like double-tee so that the skimmer effluent went down a pipe that fed the scrubber, and that pipe had a tee off to a open-drain with a half trap, that could work. Like this

This is my sketchup of an emergency overflow design for a overflow-fed scrubber, the idea being that if the slot clogged there would be another path for the water to flow. Same concept here except the purpose of the double-tee/double elbow is to eliminate back pressure on the skimmer, however unlikely that is. It also acts as a siphon break which is equally as likely with a direct sealed line from the skimmer.

Make sense?

Yup that would work, looks like im off to home depot this weekend.

 

[pskelton]

Two weeks ago I decided to increase my lighting. The bulbs are about 4 inches from the screen (which is 7" wide and about 10" long). I replaced the 23 watt CFL bulbs with 42 watt bulbs (1 bulb per side). Photo-period is 18 hours on and 6 off. The first week the algae growth increased and almost seemed to be getting green (mostly noticeable after I first clean the screen).

But the last day or two these spots are developing, and I'm wondering if you think I'm burning my screen?

Should I cut the photo-period in half at this point?

Does it seem like I have enough light to be effective yet? My DT algae problem is holding on...

Thank you!

Looks like pods eating algae on your screen. Make sure you wash your screen in tap water each time you clean it so that you kill the pods. I think it that it is too soon to start playing with you lighting cycle. It is my experience that it takes about 2-3 weeks of running to determine the full affect a change will have on your scrubber. Just make sure you wash your screen on each cleaning and be patient.

 

[srusso]

Looks like pods eating algae on your screen. Make sure you wash your screen in tap water each time you clean it so that you kill the pods. I think it that it is too soon to start playing with you lighting cycle. It is my experience that it takes about 2-3 weeks of running to determine the full affect a change will have on your scrubber. Just make sure you wash your screen on each cleaning and be patient.

+1 - those spots are pods eating the algae. Just as pskelton said, be sure you run the screen threw fresh water to kill the pods after each harvest.

 

[Floyd R Turbo]

you can also shut the pump off halfway though the week and pour a few cups of RO/DI water over the screen, and that will help keep the pods population down. Also make sure your screen is plenty rough, which will help the algae hold on instead of detaching when the pods munch on it.

 

[Floyd R Turbo]

I finally got around to moving everything from the temporary tank at my house back to the office in their new home.

I haven't installed the scrubber yet because I had to make some modifications. After the issues I had with light bleeding into the display tank at my house, I decided to block all the light that I could, so I skinned pretty much everything I could with 1/8" black acrylic

Here's how it looked before (this is a pic of the box before it even touched water)

And here are my mods to it

Removable covers

On the end (in the pic above) I extended the end bracket so that it will sit on the top edge of the sump. The other end will 'stand' in the sump, so I had to make a leg for that

I 'field fitted' this leg and brought it back home to shore it up (as shown) as it was pretty wobbly (15 lbs without water)

This will be pump fed on the new tank, the old one was overflow fed, but the new overflow system is a beananimal with 3000 GPH going through it and I just didn't want to mess with that. I decided to take advantage of the new screen sizing guidelines, since I had to cut a new slot tube anyways. I made the new slot 14" long instead of 20" and will use the leftover screen sections for a small scrubber on the 120 at home, which will house another temporary system for a while longer (if you call since April "temporary").

I'll take some more pics of the system when I install it...also I have a thread running on this system here for anyone interested:

http://www.reefcentral.com/forums/showthread.php?t=2061389

 

[Floyd R Turbo]

I totally forgot about the scrubber drain system.

I did away with the male/female coupling idea and took a page from a user on this thread (somewhere along the line) and siliconed in a small piece of 1" PVC into the holes like so

And then cut up some 1.5" PVC to make a drain pipe like so

This will be held on to the underside of the box. So the idea here is that the short pipe sections in the screen box (which fits inside the light frame box) allows the water to drain out without gurgling (my top-of-tank setup was very quiet, if it wasn't for the long drop to the tank), the pipe sections extend below the bottom panel of the box so that water doesn't 'wick' or 'creep' along the bottom of the inner/outer box, and there is an air break between this and the drain system, so there's no chance of flushing/purging/gurgling, at least not at that point.

The 1.5" pipe has a tee on the end, and what I don't show is the second tee below that, which has a piece of the plastic canvas inserted into it to break the fall of the water and direct it out the side of the tee, where it will go into a section of the sump so that the bubbles may diffuse. If you read my build thread, you will see I have fully embraced plastic canvas as the unsung wonder aquarium product. I have found so many uses for this stuff that I went and bought about 10 sheets of the stuff in various sizes.

Anyways, will post more as it comes...

 

[alaska clowns]

Well... I do have a ton of pods in my tank! Good thing I have 3 wrasses coming in the mail today I rinse in tap water when I clean, and I'll try pouring some fresh water over it in between.
At this point, if the screen wasn't rough enough, would there be a solution other than replacing the screen with a rougher one? Don't know if that's the problem or not.
Thank you!

 

[Floyd R Turbo]

Yes, when you clean it, use a hacksaw blade to scrape off the algae, which will rough the screen up well. I do this periodically, maybe once or twice a year. You can also rough it up with a hole saw after cleaning, it won't kill off your screen to do so.

 

[jimrawr]

Well I finished my ATS, what do you guys think? For lighting I am using the 23w spiral bulbs which are equivalent to 100w, the flow I used a mag 7 tuned back with a ball valve, the total flow is around 395gph on a 9.5" screen. I know thats a little more than whats suggested, but when I ramp it down the water doesnt flow across the screen evenly. The lights are perfectly centered as I have a very limited space to work with

 

[parrotchute]

The MD7 should be more than enough and maybe overkill. If it were me I would get an MD5 (49w) or the 7 and probably valve it down if I thought I might need to have higher flow for some future possibilities.
I bought one of those marineland submersible type pumps once. Not impressed with the quality, seems more like a toy than a hobby pump. It cr@pped out prematurely too.

CAN you have too much flow? What would be the con?

 

[JohnnyB in SD]

I don't recall seeing anyone with the problem of too much flow, is usually not enough. I think you can get over spray, noise or something if you get really crazy. Floyd would know.
Seems that people often try extra pumps (usually little MJs) they have laying around and quickly find their flow is lacking.
IMO is better to go with higher flow pump and valve it back if needed than buy one with borderline flow. You just don't want to go way overboard & waste too many watts, unless you live somewhere like Iowa where they give electricity away.
Personally, I'm shooting to feed my next build from the tank overflow and not need the extra pump.

 

[parrotchute]

Yeah, I could see spray and noise I guess. Or maybe too much flow literally pushing the algae off of the screen.

Of note, I think my LEDs are burning the middle of the screen a bit, so this week I'm experimenting with the screen off one hour out of every four to see if that makes a difference.

 

[parrotchute]

Yeah, I could see spray and noise I guess. Or maybe too much flow literally pushing the algae off of the screen.

Of note, I think my LEDs are burning the middle of the screen a bit, so this week I'm experimenting with the screen off one hour out of every four to see if that makes a difference.

 

[Floyd R Turbo]

You can use as much flow as you want as long as your screen is rough enough, you just widen the slot to deter spraying form the pressure. I haven't heard of anyone using more than 70 GPH/in, but that doesn't mean you can't. The higher the flow, the better. Higher flow tends to pull the algae from the screen in sheets, so having a significantly rough screen that is fully 'cured' is important.

Nutrient exchange in balance with light is something to consider too. It is feasible that a high flow screen could 'take' more light per square inch without going yellow or burning. I wonder if this is the answer to the problems with spotting / diffusion when using 3W LEDs....hmmmm...brainstorm occurring...

 

[SPotter]

You can use as much flow as you want as long as your screen is rough enough, you just widen the slot to deter spraying form the pressure. I haven't heard of anyone using more than 70 GPH/in, but that doesn't mean you can't. The higher the flow, the better. Higher flow tends to pull the algae from the screen in sheets, so having a significantly rough screen that is fully 'cured' is important.

Nutrient exchange in balance with light is something to consider too. It is feasible that a high flow screen could 'take' more light per square inch without going yellow or burning. I wonder if this is the answer to the problems with spotting / diffusion when using 3W LEDs....hmmmm...brainstorm occurring...

I am using 3w leds on my current scrubber and was having significant yellow growth. I moved the heat sinks back as far as they could go and have increased my flow significantly which has resulted in a nice healthy green screen once again. So I definitely think there could be a need for higher flow rates required for 3w led systems.

 

[JohnnyB in SD]

Good to hear you have your algae back on track.
How far are those 3w LEDs from the screen now?
Any idea how many GPH you're doing?

 

[srusso]

Good to hear you have your algae back on track.
How far are those 3w LEDs from the screen now?
Any idea how many GPH you're doing?

+1... this is very interesting

 

[SPotter]

I will measure tonight but they are easily 4-5" back. I will also try to calculate the flow. I also cut back the photoperiod to a total of on 16 and off 8.

Steve

 

[srusso]

I will measure tonight but they are easily 4-5" back. I will also try to calculate the flow. I also cut back the photoperiod to a total of on 16 and off 8.

Steve

If you switched to a dim-able driver you wouldn't have to move them at all.