Algae Scrubber Basics

[Scrubber_steve]

Originally Posted by Floyd R Turbo

You've seen CoralVue's attempt at doing this, right? The IceCap scrubber?

Not all that familiar with them or their scrubber, but at a quick look, it is cheap & poorly designed.

Seems like they had no one who new what they were doing design it for them.

If coralVue need the services of someone with experience to help them, I'm available.

I could even sell them my innovative design.

[Floyd R Turbo]

Bingo. I knew I wouldn't have to follow that with anything...anyone who has done a little research and built a few units can quickly spot what's going on with their design...which is one reason why the largest online reef equipment retailer isn't carrying it.

[SantaMonica]

Ok here's the second growth pic of 2020

[SantaMonica]

And the second

[ComicCaper]

Starting to do my research, thoughts on these two lights:

45W Grow Light

ANKE Grow Light

Tank is 120 gallons, Reef, feeding will be one cube per day.

Once I get farther into the design side, I'll post some drawings to get some thoughts

Thanks all.

[Floyd R Turbo]

ACKE over that other one, stronger LEDs. That 45W one is junk IMO

[HarrisonMG]

Just scraped this itsy bit of gunk off the screen. This is 3mo worth, although right after I noticed there were some clumps in the sump.

I think it's low nutrients cuz my nitrate test kit was reading 10ppm for months and I got a new one which told me flat out 0 every time. Phosphate 0.25ish.
Been feeding heavily last couple weeks and got the nitrate up to 5, and saw some slight improvement in terms of growth until this!

Any recommendations? Might I need to get a fertilizer or something? ICP test results are sent out to see about trace elements, awaiting those.

[Floyd R Turbo]

Are you saying that you waited 3 months to harvest/clean the screen?

[HarrisonMG]

Well a couple months ago it was growing really well and had been since last summer and then I noticed this time, only in certain spots. It was patchy. Then it mostly died so I scraped everything off. Then not much of anything really grew back on until a bit over the last couple weeks but the other day it must've died again.

I've been having problems with my softies and think I might even figured out it was the nitrate test kit. It read 10 when the whole time (since maybe Jan) it had been 0. Phosphates are at .25. So I would assume it was low nutrients; although I've been feeding quitr heavy and the numbers are going up.

Doing something wrong?

Thanks!

[Floyd R Turbo]

pics of scrubber? It does sound like you're stripping out the nutrients

[HarrisonMG]

Sure. the pic of the empty screen is today. The full screen is January. The one with only a bit of algae growing is 2 weeks ago. Thanks!

*I should note that I used to clean the screen every 10-12 days.

[Floyd R Turbo]

What to the lights look like, and how long have you been running them/day?

[HarrisonMG]

the size of the light is the same size as the scrubber. there is a diffuser between light and scrubber. Usually I would run it for 5-8 hrs in the middle of the night. For now it is on for 2 hrs, with the intention of not trying to let it suck up all the nutrients in case that is the root cause. That wouldn't end up killing it?

[SantaMonica]

Needs much more light, and weekly cleaning.

[HarrisonMG]

Originally Posted by SantaMonica

Needs much more light, and weekly cleaning.

Ok. I will set it to be on longer.
I should clean it even if there isn't much of anything on it?

Also, I'm concerned that if I give it light to grow in a fashion that it would suck up all the nutrients, then my corals would resume dying. I saw there is a chaetogrow product, and that there are certain other fertilizers you can give for a refugium.
Any thoughts on those? Or is it just a matter of feeding a ton?

Thanks for the feedback!

[SantaMonica]

Yes you need to get the slime off so that gha can attach. Plastic screens cannot hold on to slime well at all.

You have plenty of nutrients in the water, which is making the growth dark. You don't need more nutrients.

Just feed more if you want more coral growth.

This also might help:

Phosphate flow out of rocks

Many people, when they get their scrubber running for the first time, get worried when more (not less) algae starts to grow on their rocks. It seems really strange, especially when nitrate and phosphate tests have been lower than before. What is happening is that phosphate is coming out of the rocks. Remember, phosphate is invisible, so you can only see the effects of it, and it always "flows" from higher concentrations to lower concentrations (just like heat does).

Example: If your room is warm, and you put a cold object on the floor, heat from the air in the room will "flow" into the object until the object and the air are the same temperature. Example 2: If you put a hot object on the floor, heat will "flow" out of the object and go into the air in the room, again, until the air and the object are the same temperature. Now suppose you open your windows (in the winter). The warm air in your room will go out the windows, and it will get colder in the room. The object on the floor is now warmer than the air, so heat will flow out of the object and into the air, and then out the window.

Think of phosphate as the heat, and your rocks as the object, and your windows as the scrubber. As the scrubber pulls phosphate out of the water, the phosphate level in the water drops. Now, since the phosphate level in the water is lower than the phosphate level in the rocks, phosphate flows from the rocks into the water, and then from the water into the scrubber. This continues until the phosphate levels in the rocks and water are level again. And remember, you can't see this invisible flow. It's like a fast flowing, but shallow, river. And it can be much more phosphate than how much you are feeding each day.

This flow causes an interesting thing to happen. As the phosphate comes out of the rocks, it then becomes available to feed algae as soon as the phosphate reaches the surface of the rocks where there is light. So, since the surface of the rocks is rough and has light, it starts growing MORE algae there (not less) as the phosphate comes out of the rocks. This is a pretty amazing thing to see for the first time, because if you did not know what was happening you would probably think that the algae in the scrubber was leaking out and attaching to your rocks. Here are the signs of phosphate coming out of the rocks:

1. The rocks are older, and have slowly developed algae problems in the past year.

2. The scrubber is new, maybe only a few months old, and has recently started to grow a lot; possibly dark and thick.

3. Nitrate and phosphate measurements in the water are low, usually the lowest they have been in a long time.

4. Green hair algae (not brown) on the rocks has increased in certain spots, usually on corners and protrusions at the top.

5. The glass has not needed cleaning as much.


Since skimmers, filter socks, etc don't remove any nitrate and phosphate, and waterchanges and macro's in a fuge don't remove much either, most people have never seen the effects of large amounts of phosphate coming out of the rocks quickly. But sure enough, it can with a scrubber. How long does it continue? For 2 months to 6 months, depending on how much phosphate is in the rocks, how strong your scrubber(s) is, and how many other phosphate-removing filters you have (GFO, carbon dosing, etc). But one day you will see patches of white rock that were covered in green hair the day before; this is a sure sign that the algae are losing their phosphate supply from the rocks and can no longer hold on. Now it's just a matter of days before the rocks are clear.

[Floyd R Turbo]

SM, review his other posts. He had a full screen of green at one point, this isn't a brand new screen.

[SantaMonica]

Some packed algae fun, with mustard from the grilled hot dogs

[SantaMonica]

A tray of morning goodness...

[SantaMonica]

First post of 2021...

Can you spot the sump waterline

[Nanook]

How are these at nitrate and phosphate reduction?