I have a aquatic life t5 with 2 hydra 52 HD, running them for approximately 12 hours. Last week I changed my lighting spectrum from 12K spectrum (100% all channels) to a more 20K (no whites). as a result my alkalinity jumped from 8.6 to 9.6 dkh within one week. I made sure to match the PAR Levels around 300-400. is this normal to expect or should I have had an alkalinity drop? what are your guys' experience with spectrum change and alkalinity consumption? does a more blue spectrum increase or decrease alkalinity consumption as compared to white spectrum? I'm thinking because the abrupt change in spectrum caused my corals to get shocked and stopped growth even though I don't see any signs of stress??
Alkalinity Consumption & Spectrum (Blue vs White)
- Thread starter dave57
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Naturally, any kind of abrupt change is going to cause the corals to have to readapt. Gradual adjustments should be done over at least a few weeks until you get to your end point.
Besides that, a PAR meter reads violet and blue spectrums lower than white, so you'd have to increase your 'adjustment factor' for the 20K to get a more true-to-life PAR number.
Besides that, a PAR meter reads violet and blue spectrums lower than white, so you'd have to increase your 'adjustment factor' for the 20K to get a more true-to-life PAR number.
Do you believe a more blue spectrum will have a higher consumption of alkalinity vs a whiter spectrum? I know there are a lot of variables but if you were to have those two what do you think?
That's really hard to say as it can differ from one aquarium to another depending on the preferences of the calcifying organisms within. Might take a while for your corals to adjust to the abrupt change of lighting and that's when you may see higher alkalinity usage.
Personally, I like the middle ground ~14K. Moderate growth, enough 'complete spectrum' to develop fluorescent as well as non-fluorescent pigmentation in the corals. With 20K fluorescent 'pop' is pronounced, but non-fluorescent colors will be muted, or absent.
BCSreef
Well-Known Member
Same here for the reasons you stated.
Bpb
2500 Club Member
@Dana Riddle did some better controlled experiments with this concept than any of us have likely done. Perhaps he can summarize or link the posted literature on it.
Dana Riddle
2500 Club Member
There was a discussion in another thread about a peer-reviewed paper that stated light peaking at about 450 nm not promoting photosynthesis (estimated by production of oxygen by zooxanthellae.) A couple of hypotheses were advanced.
What you are seeing *might* be a case of chromatic adaptation, where the pigment ratios in zoox were tuned to a specific spectrum. I expect the alkalinity modulation is temporary (week or two) but could you keep us posted please?
I have some data I never published about chlorophyll content in zoox/Porites in response to changes in light. It's been years since I made these observations and other than responses were rapid, I don't recall particulars. I'll try to find that info.
What you are seeing *might* be a case of chromatic adaptation, where the pigment ratios in zoox were tuned to a specific spectrum. I expect the alkalinity modulation is temporary (week or two) but could you keep us posted please?
I have some data I never published about chlorophyll content in zoox/Porites in response to changes in light. It's been years since I made these observations and other than responses were rapid, I don't recall particulars. I'll try to find that info.
If you were running channels at 100% and dropped the whites (but kept the blues the same), then I don't see how you would have been able to match your par levels unless you lowered the lights. You effectively reduced the amount of light you were supplying. Now, if you have decreased your white channel and increased the blue channel, then I could see how your par levels would have stayed the same. Or perhaps you measured and adjusted after adding in the T5 lights and were just LED before?
To me, it sounds like you decreased your light, so the alkalinity usage declined slightly from less consumption, and thus, you are now showing higher dkh levels than before.
I was going to say the same thing. The best looking led tanks I have seen had their lights on all channels at 100%. From what I have seen just blues won’t pull certain colors out in acropora. I think the decrease in consumption is telling you the change was not as good as before.
