Confused about Skimmers

[meowzer]

Quote:
Originally Posted by florida joe http:///t/388866/confused-about-skimmers#post_3433019
for you my sweet potato http://www.markstraley.com/aquarium/algae_turf_scrubber.aspx
Thanks....it doesn't look like it takes that much room either

 

[snakeblitz33]

Meowzer, the scrubber that is built in that DIY is... not very good.
I would have used a little oversized pump and tuned it down a little. I would have also added a couple of unions on either side at the top. You can then disconnect the entire top instead of taking the whole thing out or cutting the zip ties.
Also, I think the problem with that screen is that it wasn't roughed up enough. By looking at the pics, it's not near rough enough to catch much algae. It only took a week and a half to start growing algae on my screens and I harvest a minimum of two handfulls off every week. Also, he didn't mention that he was washing the screen under tap water after harvesting it. Washing it under tap water after a harvest kills some pods eating the underlayers of the algae and it also washes off bits of algae that were dislodged from cleaning it.
Also, from the first pics that were posted of the scrubber, the lights weren't near close enough to the screen to be effective. Later, when the lights are moved closer to the screen, he starts seeing some algal growth.

 

[snakeblitz33]

Oh, and also in the first pic of his algae scrubber actually running, you can see that the water is not flowing down the screen in a waterfall, it's irregular and not enough. The irregularity was caused by the strip that was cut in the PVC is not straight enough. The flow rate is another concern. If the whole screen is not getting water flow, it would severely limit the amount of algal growth on the screen...
Anyways, just a few pointers.
Sorry to the OP of the hijack.

 

[jstdv8]

Everything you need to know about skimmers is in an old thread of mine somewhere on here.
Snake is right. There are guidelines, its a bit more complicated than just running some water down a screen next to a light source.... but not much hehehe.
Snake: I know he says its good to 100 gallons but I don't really get that. he grows more algae in the T-5 setup than I do on my screen and mine is more than sufficient for my 120 with a 55g sump. Doesn't seem to add up. They are so powerful I almost think you could do with half as much as is recomended and still keep your trates and phos at 0. Not gonna try it, just sayin'
I haven't checked my trates and phos in my tank in approx a year. The scrubber does it's job, no point anymore.
Quick Guideline, using feedings:
Each cube of frozen food you feed per day needs 12 square inches of screen, with a light on both sides totaling 12 real watts. Thus a nano that is fed one cube a day would need a screen 3 X 4 inches with a 6 real watt bulb on each side. A larger tank that is fed 10 cubes a day would need a screen 10 X 12 inches with 60 real watts of light on each side. If you feed flake, feeder fish, or anything else, you will need to blend it up super thick, strain out the excess water, pour it into a cube, and see how many cubes it is. And for Nori, 8 square inches = 1 cube.
Quick Guideline, using gallons:
0.5 real (not equivalent) fluorescent watts per gallon MINIMUM [0.13 watts per liter].f; line-height: 18px; background-color: rgb(225, 235, 242); " />
1.0 real (not equivalent) fluorescent watts per gallon for HIGH filtering [0.26 watts per liter].
1.0 square inches of screen per gallon, with bulbs on BOTH sides (10 x 10 = 100 square inches = 100 gal) [1.64 square cm per liter]
2.0 square inches of screen per gallon, if vertical but lit on just ONE side. [3.28 square cm per liter]
4.0 square inches of screen per gallon, if HORIZONTAL [6.56 square cm per liter].
1.5 real (not equivalent) fluorescent watts per gallon if HORIZONTAL [0.4 watts per liter].
18 hours of lights ON, and 6 hours of lights OFF, each day.
Flow is 24 hours, and is at least 35 gph per inch of width of screen, EVEN IF one sided [60 lph per cm].
Very rough screen made of roughed-up-like-a-cactus plastic canvas.
Clean algae off of screen every SEVEN (7) days.
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Note: If your scrubber is 1-sided instead of 2-sided, you'll need twice the wattage (or you'll need to feed half as much) in order to make up for the inefficiency of 1-sided screens.

 

[snakeblitz33]

Very well said, Jstdv8. And congrats on 3,000 posts!

 

[florida joe]

Quote:
Originally Posted by SnakeBlitz33 http:///t/388866/confused-about-skimmers/20#post_3433088
Oh, and also in the first pic of his algae scrubber actually running, you can see that the water is not flowing down the screen in a waterfall, it's irregular and not enough. The irregularity was caused by the strip that was cut in the PVC is not straight enough. The flow rate is another concern. If the whole screen is not getting water flow, it would severely limit the amount of algal growth on the screen...
Anyways, just a few pointers.
Sorry to the OP of the hijack.
My 02. Algae growth is not predicated on water flow, it is predicated on nutrient exposure and illumination.
It is an established fact that the crucial factor for a turf scrubber is wave action. Julian sprung references the fact that there is a radical drop off of the photosynthesis mechanism without surge. The aim is not to have a waterfall effect over the screen but more of a broken up patter which serves as a light flasher by moving the filaments of the algae back and forth. This movement then presents both illumination and shade for the algae. The broken up water also facilitates the exchange of metabolites needed or excreted by the algae

 

[2quills]

Quote:
Originally Posted by florida joe http:///t/388866/confused-about-skimmers/20#post_3433182
My 02. Algae growth is not predicated on water flow, it is predicated on nutrient exposure and illumination.
It is an established fact that the crucial factor for a turf scrubber is wave action. Julian sprung references the fact that there is a radical drop off of the photosynthesis mechanism without surge. The aim is not to have a waterfall effect over the screen but more of a broken up patter which serves as a light flasher by moving the filaments of the algae back and forth. This movement then presents both illumination and shade for the algae. The broken up water also facilitates the exchange of metabolites needed or excreted by the algae
Makes sense but when there are guys out there pulling algae out of there tanks every 7 days that look like this out of a 120g system then I have to wonder how necassary it is to have the surge effect?

Good flow = continuous nutrient exposure. It's already a well known fact for vertical scrubbers that the more flow you have the better the results will be. That is, if the screen is being supplied with the proper amount of light in the right wavelengths to stimulate such growth in conjunction with good flow. Scrubbers with low flow, don't produce nearly the same results.

 

[florida joe]

Quote:
Originally Posted by 2Quills http:///t/388866/confused-about-skimmers/20#post_3433213
Makes sense but when there are guys out there pulling algae out of there tanks every 7 days that look like this out of a 120g system then I have to wonder how necassary it is to have the surge effect?

Good flow = continuous nutrient exposure. It's already a well known fact for vertical scrubbers that the more flow you have the better the results will be. That is, if the screen is being supplied with the proper amount of light in the right wavelengths to stimulate such growth in conjunction with good flow. Scrubbers with low flow, don't produce nearly the same results.
First let me say, I seriously doubt that someone is pulling that much algae growth out of their tanks EVERY seven days. I don’t even think it is possible to get that growth over again in seven days even if you tried. There is no correlation between flow rate and flow pattern.

 

[2quills]

Your skeptism is understood. I've followed many of Floyds threads and videos across a couple of different sites. he doesn't seem to be the type that would go out of his way to give false information. He is merely one example of many who have scrubbers that grow like that. Ofcorse, one should understand the amount of food that is going into the system on a daily basis to produce such results.

 

[jstdv8]

Joe,
SantaMonica stated quite some time ago that the surge didn't make a significant contribution to the growth of the algae. At least not enough to make it worth the extra know how and parts and a sound that is not unlike a toilet flushing every few seconds.
I don't get that much growth in 7 days but I'm also not running T-5's like that system is. And like 2Q said most of us aren't feeding as much as he does to his tank.
I do feed heavily for the amount of fish I have though.
I'd say my screen grows about 1/4 of that much algae in a week on one side every single week. Which is plenty sufficient to do what it's designed to do.

 

[florida joe]

I think this would be a good topic for a thread all on its own. That being said and not wanting to highjack let me finish my part by saying IMO for that much algae growing(pic of screen posted) weekly there would first of all have to be a system devoid of any other forms of nutrient export via mechanical or biological. (No protein skimmer no weekly water changes no anaerobic bacteria dinitrification no algae growth within our DT). The massive amount of organic material needed to facilitate that growth would IMO mean that the DT is grossly over feed or is grossly over populated. Can you post the link where the info on surge not being a factor facilitating the exchange of metabolites needed or exchanged by the algae on the scrubber screen?

 

[jstdv8]

Here are a couple pics of my screen I just cleaned. It's a little black in some spots because I need to change the bulbs soon.
The screen is about 9" x 12"
Not sure why they came out sideways LOL

 

[meowzer]

OMG...that is a lot of algae....How long did it take you to grow all that?
do you have a picture of your actual scrubber?

 

[2quills]

Your assumptions are correct Joe. No other forms of filtration are being used on the tank that belongs to the scrubber I posted above. No water changes, it is a little heavily stocked. And fed several cubes of food a day. The point was to prove that surge methods or dump box styles of scrubbers aren't necissary in order achieve the objective of high nutrient export. Ill find the video of the tank tonight when I get home. As far as links, would a whole site dedicated to folks running scrubbers suffice?

 

[jstdv8]

Maybe Meo or another mod can move the scrubber portion of this thread to its own. sorry for the hijack, but there is some good info to be had here.
The picture of the long screen that 2Q posted is from Santa monicas T-5 scrubber.
He feeds alot, he does not do water changes (Hasn't since 2008, he doses for his corals of course) he has no algae in the DT (that's kinda the idea), There is no mechanical filtration other than the scrubber, no filter socks, no skimmer, no other filtration at all. Mine is run the same way although I don't feed as much as him I think. I'd get better growth if I had more fish to create more waste.
But part of the concept is to not have to feed your corals because of all the food and fish poop that is allowed to break down into coral food instead of being removed from the system.
I'll see if I can dig through his site and find where he was talking about the surge. originally he thought it was a big deal, but later posted that the results weren't all that great.

 

[jstdv8]

Quote:
Originally Posted by meowzer http:///t/388866/confused-about-skimmers/20#post_3433281
OMG...that is a lot of algae....How long did it take you to grow all that?
do you have a picture of your actual scrubber?
That's 1 weeks worth of algae growth on one side of the screen
I have some pics of a scrubber I built at a frag swap meeting to show.

This is the basic set up with the little T on the right side of the pic going to a hose that connects to the pump, you could also connect this right to your overflow and not need an extra pump at all depending on the GPH of your overflow and the needs of your screen. I actually gave this one away to the person who owns the tank on the right side of the pic.

 

[snakeblitz33]

This is one weeks growth on a 110g that was started with tap water. The display tank is completely clean of all hair algaes with the exception of some halimeda and some yet unidentified macroalgae that is slowly going away. I clean half the screen once every week, as per the guidelines in SantaMonicas threads.

 

[jstdv8]

joe here is the link
http://algaescrubber.net/forums/viewtopic.php?f=9&t=68&p=5953&hilit=surge#p5953
doesn't really say much in the way of a scientific reason other than its just a lot harder to make than a constant waterfall and they are noisy.
Q: I've heard you have to "pulse" or "surge" the water to get best results.
A: This is not proven. Most scrubbers use a constant flow, and have great results. Thus it is not recommended to use a surge device. Plus, surges are noisy, and are just too difficult to build.

 

[snakeblitz33]

Quote:
Originally Posted by Jstdv8 http:///t/388866/confused-about-skimmers/20#post_3433277
Here are a couple pics of my screen I just cleaned. It's a little black in some spots because I need to change the bulbs soon.
The screen is about 9" x 12"
Not sure why they came out sideways LOL
Does yours always grow such dark green algae? The lights that I use, at 4" produces that really bright green algae you can see in the above post. When I was reading through the scrubber threads, some argued that the bright green algae was better for nutrient export. Can you post your water parameters??

 

[florida joe]

The algae growth is impressive, and those pics represent the amount of growth you get weekly. Also does the elimination of algae in your DT inhibit the keeping of omnivores and herbivores ?