Modern LED scrubber light

[SantaMonica]

especially the usual reef setup with tons of live rock.

I should have said "except for rock or sand".

run a protein skimmer automatically an hour/two per day, for safety.

This does not do anything "for safety". It just removes 1/24 of the food of the day.

This will result in people doing ok for a while, then having various corals and such get oddly sick as various chemical concentrations get out of whack.

Not true at all. Algea is the natural filter and feeder of the entire ocean. The reason that the balances are what they are in the ocean is because the algae made it that way. So when you use algae, the levels get to where they need to be. Plus, many tanks, including mine, have gone a long time with algae-only filtering. Some 10 years. Matter of fact, it is the NON-use of algae that gets things "out of whack", because then you don't have the natural feeder and filter that operates the ocean.

You get enough green algae growth on your screens to be worth scraping off every week. Basically, this means the light/flow/screen is good enough for basic functionality.

This doesn't mean anything. If people are going to come to this site and build something that is "supposed to work on their tank", then it's irrelavent how much algae grows on thier screens. All that matters is how much filtering they get.

But while algae growth has really slowed in the main tank, it is still there, so I
need to make my ATS larger and tune it to really out-compete, before I can consider it a great success.

Correct.

[rygh]

run a protein skimmer automatically an hour/two per day, for safety.

This does not do anything "for safety". It just removes 1/24 of the food of the day.

When something dies and disintegrates, a protein skimmer can deal with that sudden surge, but an ATS can't grow that fast.
A short spike of N/P is no big deal, but if that kills something else, you can get a chain reaction.
But a skimmer only on a few hours a day may not do that much anyway. So I may have to rethink that.

This will result in people doing ok for a while, then having various corals and such get oddly sick as various chemical concentrations get out of whack.

Not true at all. Algea is the natural filter and feeder of the entire ocean. The reason that the balances are what they are in the ocean is because the algae made it that way. So when you use algae, the levels get to where they need to be. Plus, many tanks, including mine, have gone a long time with algae-only filtering. Some 10 years. Matter of fact, it is the NON-use of algae that gets things "out of whack", because then you don't have the natural feeder and filter that operates the ocean.

You might have missed the sentence just before that on trace dosing.
To clarify: I feel that water changes are valuable for the ADDITION of nutrients that get used by everything, including algae.
Sure, algae takes things out. But what puts things in? Food and air is about it. Well, and the obvious calcium/alkalinity.
For example, my iodine absolutely plummets without water changes / dosing.
Seems a bit worse after the ATS was put on, but one of my soft corals is growing like crazy now so who knows.
Then there are the others, like Strontium, etc. I don't want to deal with testing/adding all that.
Water changes are a pretty simple way of keeping all that straight.

Running a tank for 10 years with no other filter makes perfect sense.
But was that a reef tank, with no water changes, and only simple alk/calc dosing?
If so, it would sure save some hassles.

[SantaMonica]

When something dies and disintegrates, a protein skimmer can deal with that sudden surge, but an ATS can't grow that fast.

When something dies, it makes ammonia. That is what kills things. Skimmers don't remove any ammonia at all. Not even a little. Ammonia is algae's favorite food.

You might have missed the sentence just before that on trace dosing.

Sure, algae takes things out. But what puts things in? Food and air is about it.

I saw it. Everything you need to put in your tank is contained in the food you feed, and in the organics produced as the algae grows. Algae is 90% of all life in the ocean; it creates 100% of the food in the ocean, from the sun. Every trace element (which matters) that is in the ocean is put there by algae. That's why algae handles metals so well.

Then there are the others, like Strontium, etc. I don't want to deal with testing/adding all that.

my iodine absolutely plummets without water changes / dosing.

Try feeding more. If you fed anywhere near natural reef levels, you'd have plenty of iodine and everthing else.

Cal/Alk/Str are not trace elements. They are basics, like salt. And dripping kalk, or dosing ca/alk, is a lot easier than water changes.

Running a tank for 10 years with no other filter makes perfect sense. But was that a reef tank, with no water changes, and only simple alk/calc dosing?

Yes, everyone knows about the IA tanks.

[rygh]

Interesting data. I may need to rethink my "safety" features. Hmm.
No idea what an IA tank is, but I will search.

At any rate, I promised to post some new results and info. Following.

[rygh]

This is the new setup. See other thread Rev2 horizontal build for details.
I want to emphasize by re-posting this here that the left part is standard CFL flood, 2 x 24W.
The right is the original 15W LED system in the beginning of the post.

[rygh]

Here are the screens, with 1 week of growth. Only up for 2 weeks, so still getting established.
While it looks yellow, that is fairly thick yellow, with some ice-plant like pale green growth, not
a simple thin dusting.

It should also be emphasized that this 200 sq inches, on a 65 gallon lightly fed, protein skimmer on, system.
So the lack of huge clumps is completely expected.

Top left screen is the CFL section.
Top right screen is the LED section.
Bottom screen is a mixture.

The LED system clearly has an issue with light distribution, but it is really too small for this size screen,
so that is a fix in progress.

The LED side is a bit darker green, but I would say there is slightly more algae mass on the CFL side. Maybe 20% or so.
Of course, that is 50W versus 15W.

[rygh]

Here is the scrapings from the screen. Pretty good.
I also included the amount of food for the same period.
I am frankly pretty amazed by how close in mass they are.
Although the basic physics say they should be.
Still, it is really good to see.

[rygh]

ON TO THE NEXT REVISION!

As stated up a ways in the thread, with the larger system, I need more LED power.
So I am building a 12 LED, 25W, spectrum optimized system. --- hopefully.
8 x special deep red
4 x blue.
Running at 700 mA
So there will be 4 sets. Each set has 2 red, 1 blue.
Each set is on a single large heatsink.
I decided not to make my own this time. Lazy, and found some surplus. Hence the odd shape.

Here is the basic set.

[rygh]

Here is the box that holds the 4 sets, and the 4 sets basically sitting on it.
Very simply plywood box, painted white, holes cut where LEDs pass through.

[SantaMonica]

The reason you have yellow on the CFL side is because it is flow-limited. When scrubbers have enough light to grow, but not enough flow to transfer metabolites, it grows yellow. This is why the LED side grew green; the light-power is lower, so it has enough flow to handle it. Thus, the LED side is currently at its max filtering, whereas the CFL side is ready to jump up in filtering as soon as flow is increased.