What's with my rainbow montipora?

[Bpb]

when I got it, it had the classic rainbow monti look. Baby blue base, green polyps in the center, red and orange on the outside. Over the year as it has grown and encrusted...it has lost its blue base and red polyps. It now has a dark purple base and all green polyps. The PE is good, it's generally happy and fast growing. I don't care for the look though. So much to the point I consider selling the whole colony due to how dull it has become. Lighting is radiums on m80 ballasts. Should not be a limiting factor. It's in the top 1/2 of the tank

 

[Eastone]

Quite often just the spectrum-shift can bring about drastic changes in coral color, however these take longer than the regular browning up and regaining lost color cycles, it may be this.

 

[ajcanale]

Low alk has always made this piece look like this for me. I kind of use it as an indicator for when alk gets too low.

 

[Ratpack]

Interesting, mine has done the exact same thing. My alk is at 7 dkh. Maybe I will try to raise it some and see if it goes back to the original colors.

 

[ajcanale]

Yeah for whatever reason the turning point seems to be 7.5-7.8 range. If you can get it consistent around 8.5 the blue should slowly come back.

 

[Ratpack]

Yeah for whatever reason the turning point seems to be 7.5-7.8 range. If you can get it consistent around 8.5 the blue should slowly come back.

What about the colored polyps? That is more important to me than the blue base.

 

[Tweaked]

I wasn't able to regain the colors in my rainbow until I lowered in the tank, got my mg to about 1350, and lowered my po4. GL

 

[ajcanale]

What about the colored polyps? That is more important to me than the blue base.

The colored polyps in my experience only exist on new growth and coincide with a whitish base.... though... I've seen pics and videos where the yellow/orange/red polyps are more pronounced.

 

[Reefvet]

Interesting, mine has done the exact same thing. My alk is at 7 dkh. Maybe I will try to raise it some and see if it goes back to the original colors.

7 isn't low. It's normal. The ocean is typically 6.5 - 6.7.

Yeah for whatever reason the turning point seems to be 7.5-7.8 range. If you can get it consistent around 8.5 the blue should slowly come back.

That's a pretty minute difference. It could be attributed to test kit accuracy.

I don't doubt that you've had the color's change but are you sure the only thing that changed in your tank parameters was .5 alkalinity ?

The greater likelihood is it's due to light or amino acids. I've been growing and researching growth of SPS for 25 years. I've seen a lot of subtle color changes due to changes in husbandry. I've never seen a .5 alkalinity change the color of any coral.

Edit: I should add I've never seen a subtle color change caused by a change of any level of alkalinity unless it's extreme. I commonly see corals growing with very little color because of unnaturally high alkalinity like 9+.

 

[Reefvet]

I wasn't able to regain the colors in my rainbow until I lowered in the tank, got my mg to about 1350, and lowered my po4. GL

So with 3 variables changing all at once you have no way of knowing which one, or combination of one or more, had the effect.

Standard ocean levels of MG are 1100-1200. 1350 isn't significantly different.

Where this coral grows naturally the MG level is lower than 1350 and it's highly unlikely there are any measurable phosphates. Light level would be subject to depth, turbidity and many other conditions. What there would be is a constant source of food.

 

[ajcanale]

7 isn't low. It's normal. The ocean is typically 6.5 - 6.7.



That's a pretty minute difference. It could be attributed to test kit accuracy.

I don't doubt that you've had the color's change but are you sure the only thing that changed in your tank parameters was .5 alkalinity ?

The greater likelihood is it's due to light or amino acids. I've been growing and researching growth of SPS for 25 years. I've seen a lot of subtle color changes due to changes in husbandry. I've never seen a .5 alkalinity change the color of any coral.

7 is relatively low in contained reef keeping terms.... I understand it is close to NSW but our tanks are not the ocean. The 7.5-7.8 reference is a range at which I have noticed that the base color change seems to occur. Like I said I use this particular monti in my system as somewhat of a reference point of when ALK gets below where I want it. FWIW I primarily use a Hannah checker with at least 2 different reagents on hand (ideally separate Lot #;s) and keep a Salifert on hand for backup. The point I'm trying to make here is that at a given point this particlar montipora takes on a different appearance, it really has nothing to do with a given range, but the particular point is on the low end of the dKh spectrum that common SPS tanks are kept . I just posted a range assuming there is a margin not only in error of a given test but also that there might be other parameters involved.

 

[Reefvet]

7 is relatively low in contained reef keeping terms.... I understand it is close to NSW but our tanks are not the ocean. ....

... I just posted a range assuming there is a margin not only in error of a given test but also that there might be other parameters involved.

I disagree that 7 is low in a reef tank. The current TOTM runs at 7-8 and it looks pretty colorful.

I run 7 with high PAR, 600+ and have few color issues. My point being there are many factors.

 

[Bpb]

This is all interesting banter. I've seen it look perfect in other tanks on my reef club way up high at the top (guy I got it from ran sol blues and had it very high), and others who have the same lineage keep it on the sandbed. I can't make sense of it. One club member suggested I frag the colony and put it in a few different spots and see where it colors best and sell the rest. It grows super fast for me and I've had it some years so im not worried about going back down to a small frag of it. It'll grow back. Plus it's made its way onto the Rockwork so no matter what, it's there to stay in one spot. It's also encrusting on my overflow