I'll do my best to catch up after skimming the thread
So I run a CW-50 clearwater scrubber on my 106 gallon system (80 DT, 26 sump). I'm trying to use it to keep my nitrates around 10 and my phos around .1. That has not happened yet. Early on I was running it 24/7 and it bottomed out my nitrates and had my phos at .06. I got dinos for a couple weeks, so I turned it off and let the "dirty" run up so the dinos would go away (they did). Today I'm around 25 nitrates and .3 phos. I don't think it's that big of a deal, but I'd like to see if I can get this ATS dialed in. I was running it for about 12 hours opposite my DT LED schedule, I just dialed the time up for 20 hours a day to see if that will curb nutrients.
Does anyone have any experience with an ATS and what are you using for a lighting schedule for it? What are the benefits you see from it? How is it impacting your nutrient levels?
I may go another route if this ATS doesn't get dialed in and do what I expected it to do.
Everyone's setup is different, so what works for one doesn't necessarily work for another. That's by far the main difficulty in weeding through advice.
CW50 on a 100g is not necessarily "too small", obviously it bottomed out your N/P so that's not the case. Getting to a balance point with your specific system is the key.
The things you can typically adjust are:
Light photoperiod
Light intensity (either with dimming, diffusion, or shading)
Water flow rate (nutrient delivery)
Are you feeding pellets or frozen and at what frequency? I switched from all pellet to mainly frozen and that seemed to help my PO4.
I wonder if running light 20 hours per day would cause photosaturation?
You are probably aware, but there is a good deal of information here:
AlgaeScrubbing
Photoinhibition or photosaturation is an instantaneous factor, meaning, related to the intensity (not the duration).
I do 2 feedings + nori twice a day - I am a generous feeder (frenzy and mysis)
It’s funny you brought that website up, I quoted that on a Facebook post when discussing it and the owner of Clearwater got on and insulted my intelligence and told me they don’t know anything. Lol. So ya, if I hadn’t bought a Clearwater brand by then I would have not after that. Totally unprofessional. I believe it was specifically concerning the need to use no light or “rest” the algae culture for best results.
Do you have other filtration in play? I didn't see it mentioned but then again, I skimmed the thread quickly
Regarding the need for a "dark period" - I'm of the opinion that this is not necessary. That primarily comes from discussion/evidence related to house plant type photosynthesis. At the root of the discussion is actually the cellular mechanism, and what holds true for plants does not necessarily hold true for algaes. There's room for discussion on this but many have shown that 24/7 lighting on an algae scrubber (specifically) does not cause negative growth compared to a cycle with a rest period. The dark period also came from Dr. Otto Warburg who besides discovering the root cause of cancer, also figured out that if you "flash" algae with light 10% of the time (90% dark period, at something like 7 kHz I believe) that you get the same level of production as if you lit it constantly. Now that doesn't mean you only need 2.4 hours of light per day, but the "dark" cycle is slower to complete and this has to do with flashing. The nice thing here is that water flowing across the algae mat causes glimmer lines (like in a tidal pol or swimming pool) so this is actually happening already in most scrubbers.
The real issue is: can your scrubber handle 24/7 lighting? The answer here should be "if" - if you have progressed through ramping up growth by increasing photoperiod, flow, and intensity over time. And also if you have a sufficient bioload and level or diversity to warrant it (to support the scrubber)
I held back from saying "only if" because there are always exceptions....
I've been thinking about this - so I've decided to ask 3 questions to ATS users:
1. Is the nutrient removal consistent and/or measurable? Meaning if the screen is "full" I see 30% less reduction in Nitrate/Phoshate or when the screen is new I know that my nitrates will drop by 5ppm, etc.
2. Using an ATS causes nutrient depletion so I dose X. Backed up by an ICP or titration test.
3. Using a 24 hour light cycle is less efficient than 18 hour....or 12 hour is better than 14 hour....any facts to back that up
BONUS QUESTION: What piece of equipment, or dosing, or whatever to you think the ATS is replacing? If any? Would you say they are a standard in your setups? A nice feature to have? Totally unnecessary?
1) Josh with Clear Water actually found a lab (happens to be literally 10 miles from my house) that can test algae samples for nutrient content. This stems out of a lot of FB and in person discussion with some of those high profile reefkeepers, basically it came out that apparently no one has ever actually tested algae nutrient content post-harvest...they've just always gone by what some book says.
2) I've got no opinion here, except that it's generally understood that trace elements will get sucked down, and this again can be variable from one system to another. I feel this can be affected also by your frequency of water changes, what salt you use, etc...
3) All dependent on the specific system. One answer doesn't not apply to all. Specific to my units, this is why I feel dimming is absolutely critical. It's the instantaneous factor (intensity of light;
rate of individual photons hitting algal cells and causing photosynthesis) that is the most influential - duration and flow are of much less effect. If you have too many photos hitting too few algal cells, you get photosaturation. Going back to the light/dark cycle: the "light" cycle fills a bucket with energy (a simplification). The "dark" cycle empties this bucket into another part of the cycle. If the "dark" cycle can't happen well, the buckets all stay full and everything slows down (or just stops). Dimming combined with the glitter-line effect allows one to "tweak" the process until you get the best growth for your specific system. Remember - intensity is the most influential factor.
