Algae Scrubber Basics

[Floyd R Turbo]

So if I understand this correctly for my 150 gallon tank, I would need the following; 15" heigh
By 10" wide then I would need a flow rate of 350gph not including any losses. That would also need to be light on both sides too. Lighting I'm ok with

That's the old guideline - see the post #'s in my sig for the updated basics. Size according to feeding: 12 sq in of screen (LxW) lit on both sides for every cube of food fed per day (average).

I use tank size as a secondary factor, once you get into the 150-200g range, then I start to look at the ratio of the tank volume to the water flow rate across the screen. Right now my rule of thumb is if you are approaching 1:1 then you need a wider screen (more overall flow) and that might mean if you only feed 2 cubes/day you might built a scrubber that is sized for 4 cubes/day, just to get the turnover rate. Plus, with a larger tank you have room to grow and might end up feeding more.

other secondary factors can be existing filtration (which will take part of the load also, thus reducing your required scrubber size) and tank conditions (like a nutrient or algae problem, which might bump you up a bit)

 

[herring_fish]

The entire surface area of the ocean provides sea air exchange of all kinds. Not just beaches. It's a lot of exchanging that goes on. Gigatons.

I did a quick google search and found that you are right and I am wrong. In the would ocean system more oxygen comes from down welling of water from the surface than comes from phytoplankton. As a side note, phyto can be as much as 20 times more effective and land plants but that is not relevant here.

I was at work and just pulling from memory. In Dr. Adey's book I quickly looked up one of the references that I was thinking of. It was more focused on modelling a reef.

Exchange and Selected Synthetic Ecosystems (Page 198)

The southern bank barrier coral reef on the Caribbean island of St. Croix can be regarded in many ways as a generalized tropical reef. It is mature, well developed geologically and biologically, and has been studied in some detail. Given the low rates of metabolic activity in the offshore water, the water moving onto the reef due to wave and current action typically has an oxygen concentration close to 6.5 mg/l, a level that varies only by a few tenths day and night [Chapter 5, Figure 10). This is essentially the saturation point. As this sea water flows in over the reef, driven by the constant trade winds, it picks up extra oxygen, becoming highly supersaturated during the day because of excess photosynthesis, that is, photosynthesis that exceeds respiration. On the other hand, at night the same water loses oxygen, due to the respiration (without photosynthesis) of both plants and animals in the reef. The effect of extensive wave breaking on the exchange of oxygen is also marked and causes oxygen loss during the day and oxygen gain at night, the net effect being to smooth out metabolic effects on the gas concentrations. .....

Algal Turf ScrubberTM (Page 234)

"¦ the scrubber keeps oxygen near or above the saturation point and effectively removes all classes of dissolved animal wastes.

 

[Becks]

Thanks floyd.

It seems every time I read good things about ats I then read so much negtive which mostly Seems to be posted on reeftank forums? Is there history here??? Mainly saying that ats add organics into the water which can't be tested causing tank crashes, that they are nutrient sinks etc etc. It seems just as I start to make progress someone posts information which seems to knock me back a step

 

[Floyd R Turbo]

the TRT is for some reason full of ATS haters like no where else. Don't know what to say, it is what it is. If you hate ATSs and want good company, you'll find it there for sure.

 

[SantaMonica]

I run into areas heavily covered in periphyton, you don't find coral, at least not much

Probably a different definition of periphyton. Every square mm of rock is covered in it, if it's not a coral.

With out the airwater interaction it wouldn't have been saturated in the first place

Photosynthesis can indeed put oxygen into the water without any air being involved, once the algae is there. Getting the algae to grow rapidly, however, is what takes the air/water interface.

oxygen comes from down welling of water from the surface

And that oxygen comes from the phyto.

ats add organics into the water

Yes, the same organics (carbs, vitamins, aminos) you buy and dose. That's why corals learned to consume those things... because algae puts it there in the ocean.

 

[karimwassef]

Hmmm. I went away for a couple of days and wham! So much cool new content.

I love the approach of the article on skimmate. But I'd want to see the results that referenced the intake water analysis too. I think a skimmer takes out what you put in it. I don't think that my heavily fed tank skimmate would match what a ULNS tank would. Or a heavily fish stocked tank vs. a sparse tank... Or even a tank with carbon dosing mucus, or one where the coral mucus is heavy vs. one without. Or one with an ATS vs one without...

By the way- I'm a lover, not a hater. I think an ATS is necessary just as I think a skimmer is. The bigger the better for both! Then feed like its a zoo.

I also don't run my skimmer constantly! At night, when I dose my phyto, amino and fattys, I turn it off. This works because the temperature also comes down from 84 to the high 78 range. Food should be in the water long enough for it to be consumed but if it's turning into waste, I'll take it out and put new food in.

I also use massive agitation in my tank to pull up material from all layers. I have a double surge that releases 2 X 20gal in alternating and then crashing formations that pull a massive volume of water suddenly from almost everywhere. There are few quiet zones during a storm and many resident seek shelter during these events... Kicking up anything there too.

In terms of cucumbers... I only keep sand cleaners. My favorites are the tigers!! The water sifters, like apples, have caused disasters and usually die in many tanks. I haven't tried any in mine: I've even had two cucumbers die when they lodged themselves in my rockwork' unusual formations. I chose to leave them there and my scavengers consumed them. Strangely enough, I've been finding baby cucumbers now too. The cucumber needs a FED tank. If you are going to have a tank on a diet, they're not for you. If you feed, they will work to keep the sand polished. With so many, they actually exhibit interesting nighttime socialization too.

I find that they are super-sensitive to oxygen levels though. When power went out, my water was unusually still for a few hours... In my water churned madness of a reef, that is not normal. I found all the urchins hugging the walls and rocks at the surface - which I interpreted as seeking more O2.

I think that simulating the surface of a reef with a skimmer is important. The injection of gallons of fresh air is just as important as the extraction of waste.

 

[jason2459]

I'm with you on being a lover not a hater. But also a realist. I love my skimmer but understand it's not the best mechanical filter. I actually like that it's not. I don't want filter socks or polishing pads etc.

I also love my ATS and I believe all healthy systems should have some kind of algae in them to harvest. But I also know it's not perfect or able to solve all my problems like high CO2/low pH. Sure it can help but just like the skimmer it's not going to do it all itself.

Everything in my system works with everything else in my system. Its a synergy. My carbon dosing, along with my excessive daily feedings, feeds everything from the ground up.

My skimmer helps remove excess growth of bacteria, diatoms, sponge, etc. (anything that will stick to a bubble...) This helps remove the nutrients they've consumed. It also helps to aerate the water and exchange gases.

My ATS (along with most any kind of algae harvesting) is great at also consuming nutrients. The same kind of nutrients the bacteria was consuming too btw. Some will argue it will also pick up harmful elements. Well, so do bacteria. Bacteria consumes more then just the common C:N that most just worry about. They all work together. The ATS also helps to consume CO2 and increase O2. Plus, itself becomes a great food source for many organisms. This will be the next thing to go into my our tanks biology up close thread.

 

[outy]

But I also know it's not perfect or able to solve all my problems like high CO2/low pH.

.

if you don't have, get a kalk reactor.


One of the better pieces of equipment I have ever purchased

 

[jason2459]

if you don't have, get a kalk reactor.


One of the better pieces of equipment I have ever purchased

Limewater is my primary pH booster. But with it I have to watch my Alkalinity. My alkalinity will go sky high before my pH does.

 

[SFish]

Ats

Ats

Ok so first build in planning stage

I have a 10x10" screen. I was look to use some of those clamp on light fixtures. I want to use LED lights so my question is what wattage lights would I need? I've been looking at LED grow lights. Also do LEDs need to be 4" away from the screen as well.

 

[Floyd R Turbo]

Low-power LED lights are not very effective - they provide a good distribution of light, but lack the power to drive the light deep into the algae mat when the growth gets thick.

First question, how did you arrive at the 10x10 size screen for your system?

 

[SFish]

I'm running about 100gallons of water and going to use both sides of the screen. So should the lights still be about 4" away from the screen.

 

[SFish]

So 50W bulbs should be good right?

 

[outy]

So 50W bulbs should be good right?

You may be missing his point.


The bulb you listed will not work decent in this application.

You need to try for the 1-3W individual led diodes, the one you listed is not the right path to follow here.

 

[Floyd R Turbo]

I'm running about 100gallons of water and going to use both sides of the screen. So should the lights still be about 4" away from the screen.

You went by the old guideline, which was 1 sq in per gallon

The new guideline is 12 sq in, lit on both sides, per cube of food fed per day - see my sig for the most recently updated Basics posts in this thread.

This will probably change your screen size and light requirements quite a bit.

Also see the post # in my sig that covers LED lighting guidelines.

 

[SFish]

Oh

Thank you

From what I see 2-3inch from the screen seems normal is that right?

 

[SFish]

You went by the old guideline, which was 1 sq in per gallon

The new guideline is 12 sq in, lit on both sides, per cube of food fed per day - see my sig for the most recently updated Basics posts in this thread.

This will probably change your screen size and light requirements quite a bit.

Also see the post # in my sig that covers LED lighting guidelines.

Thank you

The problem I have is I don't have fish right now.

 

[SFish]

Led

Led

Would a light like this work?

 

[Floyd R Turbo]

Nope, low power LEDs. Rule of thumb I follow is 1W or 3W individual LEDs, and if they don't need a heat sink, they're not strong enough for a scrubber

 

[SFish]

Ok now I'm confused can you give me am example of what will work