Green Slimer Turning Purple on Bottom

[lrosenberg5]

@Dkmoo I haven't measured my PAR. See the screenshot, this is the settings I am running at with a 20% reduction (acclimation mode).

From what I have read, I was under the impression that the single AI Prime light would be sufficient for the 20 cube. The settings you see in the photo is how I have been running the tank since I got it ~6 months ago. You think It's worth trying a different preset?

Also not sure how I would go about measuring my PAR given the price of most PAR meters on the market.

 

[Dkmoo]

@Dkmoo I haven't measured my PAR. See the screenshot, this is the settings I am running at with a 20% reduction (acclimation mode).

From what I have read, I was under the impression that the single AI Prime light would be sufficient for the 20 cube. The settings you see in the photo is how I have been running the tank since I got it ~6 months ago. You think It's worth trying a different preset?

Also not sure how I would go about measuring my PAR given the price of most PAR meters on the market.

I see. With it comes to SPS like acropora, they really need 200+PAR minimum. Im afraid with a single Prime, changing to a different setting won't help. Even at 100% max on all the channels im thinking at that spot on the rock, you'd barely get 200. There's just not enough juice. Plus, you still want that that blue heavy spectrum mix so you really won't be able to get to those high numbers without additional light supplementing.

With your current setting + a 20% reduction, if i have to guess (strictly based on my own experience measuring my own tank back when I had 1 prime), I'd say that where you glued the slimer is getting MAYBE 125 to 175 par. Bottom of the tank at 50 to 100 PAR, and top of the tank 1/3, where you currently have no rock to mount anything, probably 150 to 200.

When they say 1 prime is enough for a mixed reef 20g cube, they mean its mixed with LPS and softies which do well in that 25 - 150 PAR range. Once you add SPS into the equation the light generally becomes lacking.

A Seneye is relatively cheap to measure PAR if thats something within your budget. Otherwise, see if you can rent a PAR meter from your LFS.

If you still have your mind set on Acropora, then I think your aquascape will need some major renovating and potentially moving frags bc even if you just keep that top of the rock at 250+par, even the bottom of your tank, which currently has no shade, will get too high for most of your current corals. You probably want to think about adding shelves and making the structure higher to get more shading. Placement will get tricky, as I mentioned in the first post, and may require a redesign of the aquascape from the ground up.

However, don't get discouraged or overwhelmed by all this. If you want to add SPS, there are other options. Really acropora is the only kind that require those high 250+ numbers minimum. The below SPS are less light hungry and can work better in your tank without too much modification:

1) psammocora - can def work in your current tank as is, need 100 to 150 PAR. This is the first SPS I added to my tank back when I had only 1 Prime.

2) leptoseris - don't need that much light. 50 to 100 works, may not even need to be on the top of your rock.

3) montipora, Poccillopora, stylophora can all do well in that 100 to 200PAR range, you may need to modify your current rock scape a little bit bc that top of the rock will get crowded.. maybe add something higher and add a shelf