Algae Scrubber Basics

[el aguila]

Sounds like my problem, that I let go for waaayyy too long, in the name of research... At least it makes me feel better if I say that.

In the process bleached and mostly killed a small blue acro colony I had going. All the corals seemed to love the light at first... They colored up nicely, but the bryopsis itself I am sure is a result of never having a QT tank or dip treating coral.

srusso the light really came on when I saw your posting last night.

To back up, my ATS now has 7-8 weeks. When I built it, I went with CFLs just to try it out and figured I could always go with T-5s or LEDs if I really liked it. The only thing that I needed to buy was the screen, CFL bulbs, and a couple of fittings. I used temporary construction lights cut away half of the cage and lined the rest with AL foil. DT lighting was a combination of solar tubes and HID Xenons (car headlights).

After week 2 I noticed that there was no algae on the glass; DT algae was dissapearing. I started feeding heavier and thought this is the best thing since sliced bread.

Then about 5 weeks after I put the ATS on line, I swaped the HIDs for LEDs. Now I can't even go a week without needing to clean the glass. Without a baseline of having run my ATS for 2-3 months, I really couldn't figure out what was going on.

I knew that I wasn't getting enough light in the ATS, so I bought 1 40W CFL and put it in last night before I saw your post just to experiment a little.

Looks like I'm going to slow down on my feeding and bite the bullet to go with either T-5s or LEDs. May throw in a few more 40 watters until I can get it done. Now to go back and read up on other lighting in this thread.

 

[redneckgearhead]

I am experiencing the same thing. But my difference is that my DT lights started over powering my scrubber lights when I started increasing the time my DT lights where on. At first they where only on 4 hours a day (trying to beat the HA). It worked my HA in my DT vanished, so I started feeding heavier (1-2 cubes a day rather than 1/2 a cube every other) and increased my lighting by two hours every two weeks until my lights where on 8 hours, and thats when I noticed the HA making a come back. I worked on my design of my scrubber and tried to make everything optimal. It helped a little but not like I thought it should, so I took two hours off my DT lights and now the HA in the tank seems to be receding.

On a side note, I hated having to have my scrubber lights (4-23 watt CFL's) so far away from the srubber to keep from "burning" the algae, so I moved them closer and turned down the time they where on. My lights are on 2 1/2 hours off 1 1/2 hours and it seems to have worked, my algae is not burning and is growing like mad. I'm also adding more flow to give my scrubber a little more power.

 

[jcooler]

smaller lighting periods

smaller lighting periods

...My lights are on 2 1/2 hours off 1 1/2 hours and it seems to have worked, my algae is not burning and is growing like mad. I'm also adding more flow to give my scrubber a little more power.

So, is that lighting cycle that you use 24 hours a day? 2.5 hours on, 1.5 hours off, 2.5 on, 1,5 off?
Did I understand that correctly?
If so, I really like that idea. Like you, I would like to move them closer, to prevent all the light spillage, but I don't want to burn the algae.

Unless someone comes up with a good reason not to do that, I think I'll give it a shot, once you confirm that I understood your lighting method correctly.
Thanks,
Jeremy

 

[parrotchute]

Thanks Johnny - yeah, I understand the eshine lights are a big variable that'll make it a little difficult! They are definitely growing algae now, though, so that's a plus. If anything, I'm beginning to suspect they are too bright - more algae is growing outside the "spotlight" of the LEDs. I've got them backed off a bit, but maybe if they continue to be a little bright, I'll add another brief "off" period on the timers. (sort of like what Scott is doing)

Yeah, I know it's too early for ME to consider splitting the screen - I was asking more to put the idea out there. What do people think about cleaning just ONE side (alternating) two times per week vs. a split screen?

 

[TheFishMan65]

IIRC several of the experts on plant life have stated that they need a respiration period of at least six hours. I just don't remember were I saw it. A lot of folks used to try and run them for 24 hours and it just didn't work.

 

[parrotchute]

Oh, and just for reference, here is what the manufacturer puts out for the PAR for eshine systems. Obviously, it's not objective, but interesting.
I'm not an expert on PAR, but it seems like, in general, PAR & spectrum would be better readings than watts for screens...

 

[redneckgearhead]

So, is that lighting cycle that you use 24 hours a day? 2.5 hours on, 1.5 hours off, 2.5 on, 1,5 off?
Did I understand that correctly?
If so, I really like that idea. Like you, I would like to move them closer, to prevent all the light spillage, but I don't want to burn the algae.

Unless someone comes up with a good reason not to do that, I think I'll give it a shot, once you confirm that I understood your lighting method correctly.
Thanks,
Jeremy

Yep that is correct, on off on off for 24 hours

IIRC several of the experts on plant life have stated that they need a respiration period of at least six hours. I just don't remember were I saw it. A lot of folks used to try and run them for 24 hours and it just didn't work.

I'm not sure about that but it seems to be working for me. Ill see if I can find some info on that. The lights do go on and off but its just in shorter cycles, 6 cycles of 2 1/2 on 1 1/2 off

 

[jcooler]

Yep that is correct, on off on off for 24 hours



I'm not sure about that but it seems to be working for me. Ill see if I can find some info on that. The lights do go on and off but its just in shorter cycles, 6 cycles of 2 1/2 on 1 1/2 off

Scott,
I'm going to give this a shot for a few days to see how it works for me. How close do you have your lights to the screen?

 

[JohnnyB in SD]

Oh, and just for reference, here is what the manufacturer puts out for the PAR for eshine systems. Obviously, it's not objective, but interesting.
I'm not an expert on PAR, but it seems like, in general, PAR & spectrum would be better readings than watts for screens...

I will be building a dual 10"x18" screen scrubber after the holidays and would like to use LEDs. I don't see having the time to research and build DIY units, so your eshine appeals to me.
You're using the 50w Nano 4G?
They seem like they will be "good enough" for your 10x14 screen?
Did you buy direct, how much they run?

 

[redneckgearhead]

Scott,
I'm going to give this a shot for a few days to see how it works for me. How close do you have your lights to the screen?

About 2-3 inches away. I moved them in close and then adjusted the lighting schedule until I had no more yellow. Originally I had my lights like 6-8 inches away to keep from burning the algae.

 

[parrotchute]

I will be building a dual 10"x18" screen scrubber after the holidays and would like to use LEDs. I don't see having the time to research and build DIY units, so your eshine appeals to me.
You're using the 50w Nano 4G?
They seem like they will be "good enough" for your 10x14 screen?
Did you buy direct, how much they run?

I bought the 50w direct, they were $75 ea. They seem more than good enough - the algae is actually growing more on the edges which leads me to BELIEVE that it's actually a little too strong and I should either move them back some more or reduce their on time.

 

[Floyd R Turbo]

short cycle *may* work. The real question is: is it the MOST efficient?

 

[parrotchute]

Ok, got a pic after a week with the new tank. Got some initial HA in the dt, hopefully it won't stick around too long. Any thoughts?

 

[zhewitt04]

On a side note, I have reason to believe I may have discovered a new "rule".

Scrubber PAR should be equal or greater than that of your display lighting.

At least this is the case for me... allow me to explain...

Some of you may or may not know my tank has become infested with bryopsis... Its bad... like a... really bad.

About 4 months ago I purchased all new lighting. Went with top of the line metal halide equipment. The change in PAR was from a crappy (ebay) 250 PAR at the water surface to now 1500 PAR... (anyone see the problem, my lighting is NOW like 4 feet from the top of the tank...)

now my scrubber didn't get an upgrade... it is still using the crap drop lights and 23w CFLs. AND if you have been keeping up with the reading the PAR reading from my scrubber are about 300 - 400...

With the scrubber being on for 18 hours a day and my tank lighting about 12 -10 hours, (I like to see my tank on early during weekends) the tank was receiving a TON more PAR then my scrubber.

So I believe I flipped the algae filtering from a sump scrubber to an entire system turned into a scrubber. Needs less to say the output of the scrubber declined over the four months, as the bryopsis did its thing and took over everything. I felt I had failed and a weed had won the battle.

Equipped with a new outlook, I will attempt to fix my own ongoing experiment of a reef tank.

Ps... yes I tried the kent magnesium thing... I am going to try and get the balance of power corrected, now that I may have found my issue. :headwallblue:

I think the main take away here is, scrubbers need lots of quality light.

Ok this is scary. I literally on this cleaning am getting GREEN stuff on my scrubber. It is looking like alot of the growths I have seen on here. After changing flow and lights and designs its about time. Then I read this:uhoh2:..... and I am switching my t5 lighting to metal halides this weekend. Is this going to screw everything up again? I am really worried. I am going from 8 t5 (54 watts) to 2 x 175 MH. (12k) and some pc lights for atinics

 

[redneckgearhead]

short cycle *may* work. The real question is: is it the MOST efficient?

Floyd, I think it has some benefits. Before with a long cycle I had to have my lights so far away 6-8" to keep the algae from turning yellow. So moving them closer and having shorter cycles *should* work. It appears to be working on the HA in my DT. So we shall see. I will let you know my findings.

 

[srusso]

Ok this is scary. I literally on this cleaning am getting GREEN stuff on my scrubber. It is looking like alot of the growths I have seen on here. After changing flow and lights and designs its about time. Then I read this:uhoh2:..... and I am switching my t5 lighting to metal halides this weekend. Is this going to screw everything up again? I am really worried. I am going from 8 t5 (54 watts) to 2 x 175 MH. (12k) and some pc lights for atinics

I am still trying to figure out display tank lighting myself to be honest. My first attempt an ebay "250w MH w/ 4 39w T5 actinics"... the T5's had no cooling so it killed brand new bulbs in short course, and the MH ballast was some crap hardware store deal. This unit was designed with legs and sat on the rim of the tank, 6" above the water surface. Thats (4*39)+250 = 406 watts of power and nothing to show for it!

My reef club loaned me a PAR meter to test, was only getting 250 to ~300 PAR at the water surface! (scrubber was working wonderfully during this time) While I had the meter I tested the scrubber, and got 350 to ~400 PAR from my CFLs with aluminum foil reflectors...

SO, a good friend gave me a great deal on some brand new equipment he had to off load, due too a failed tank upgrade project. I now have a Lumatek 400W Multi-Wattage (250W, 400W) Ballast. A Radium 250w mogul based 20K MH, and a CoralVue reflector (looks like mirror inside). Hung it 8" away from the surface and PAR tested... 2500! Moved it to 13" from the water surface... 1500 PAR! (At this point my wife is getting ****ed b/c the "fish tank light" is now lighting the room more than the tank)

Left it at 13", it was all I could manage cut the time back in effort not to shock the corals. I am not going to lie, I was rather proud of my 1500 PAR... I'd say once I reached about 6 hours a day thats when I started noticing some algae growth in the tank.

If you do some shoty math...

Display - 1,500PAR x 6 Hours = 9,000PAR a day
scrubber - 400PAR x 18hours = 7,200PAR a day

To make thing worse the schedule got to its normal 10 hours a day and about 12 hours a day on the weekends....

By this time the scrubber was nearly producing nothing, I had started dosing kalk, still feeding the same crazy amount of food I had always been feeding when the scrubber was working normally... and for the last two months been heart broken and ready to give up...

That brings us to about three weeks ago, Bryopsis had choked out my zoas, had grown its roots into some SPS. Monti's seem fight it off well, and its covered my claim, it still opens fine though... I turned off the tank lights now for almost two weeks now. My scrubber growth was dark green/brown this week... cleaning it now every 4-5 days.

Even though the light is off, I raised it to the top of my ceiling, about 3ft... lol

I went from grossly inefficient lighting to extremely efficient, well actually too efficient... Like Yankee stadium in my living room if the light is on... Either this light now has to be replaced, or the tank goes to the basement...

In the mean time I plan to frag what is still left alive, setting up a QT for the corals while I figure out my lighting issues yet again...

 

[perpetual98]

Almost sounds as if DTs with massive PAR need to have a different calculator? At some point even with the best intentions, you're going to either run out of room or have a massive ATS that is going to require as much in lighting as your DT. A nice tumbleweed of cheato in addition to the ATS? Hard to say.

 

[srusso]

...to make things even worse I just found my post in the advanced scrubber thread (post #30) when I took my PAR reading for my scrubber...

226 -302PAR... that makes it even worse then I originally believed. :hmm5:

 

[srusso]

In summery, I believe a scrubber requires more or equal PAR for your scrubber than the PAR reading of the water surface of your display

That may seem crazy but...

Your display is X deep. The layer of water flowing over your scrubber is very thin... And you can put the lights as close to the scrubber as needed.

So you need good lighting for both your scrubber and your display, but the scrubber PAR requirements are far easier to achieve.

The formula may be

Display PAR x display Hours = or < scrubber PAR x scrubber hours.

 

[perpetual98]

Can you get crazy PAR in the right spectrum without burning your algae? Or is that where fiddling with the on/off times comes in? I still haven't set up my ATS as my tank is still cycling and I haven't had time to build a frame for mine since I have too much going through the overflow for a 7" slit to handle without it just making a big mess.