Brown spots, looks like nicotine stains on live rock? ID help...

[Jeremiah]

I'll try and get a decent picture of what is going on tonight, but i've seen these dark brown spots on my live rock for months and figured it was time to figure out what it was.

Did a lot of searching and the only thing everyone seems to say when you say brown spots is diatoms. I'm pretty sure it isn't diatoms.

At first I thought maybe it was dying coraline, but any coraline that i've ever seen die has turned white. (I'm still considering myself new to the hobby so I could be wrong) The reason I was thinking that is because in the area with the highest concentration of those "stains" is the area of highest flow and highest light. As well as the least amount of coraline growth. It is funny because RIGHT below that area in the shade w/ much lower flow it is the area of most coraline growth in my tank.

All my levels seem fine, alk is always around 6-7dk...PH gets pretty high swing 8.1+ to 8.6+....Calcium always around 430 or so. I've not started testing for mag. nitrate always under 5, all the other levels are either low or i can't read on my test kits. My corals are happy, except for the stuborn zoa colony that just chooses to stop opening periodically.

If anyone has any ideas/stuff that I should look up to see if it looks or sounds like what I'm talking about, it would be appriciated.

 

[jda123]

Check out brown coralline on google. Brown, dark burgundy and black all grow at higher light levels than purple. Coralline comes in just about every color.

 

[kmcmurtry]

I apparently have the same thing - glad you asked Jeremiah. I was starting to worry too, but it does seem to be a non-fuzzy, hard substance, and I have plenty of other colors of coralline, so why not, lol.

 

[Jeremiah]

Hmm...mine seems to be hard also, but over that area it does seem like i'm seeing a peach fuzz. I dunno....Couldn't really find a good thread on the different corallines. I'll try again when i'm off work tonight, hopefully it is just a darker coralline.

 

[SkyShark]

Do your fish smoke?

 

[sethsolomon]

On the context of coraline... Anyone have any yellow coralline algae? I will trade some neon orange coralline for it.

 

[Munch]

Isn't alk 6-7 a bit low?

 

[Jeremiah]

Yup 6-7 is a bit low, I would rather it be 7-8 or higher. I think the ocean is what 7?

However what I noticed was that the more I dosed ALK the higher my PH kept going. So I stopped to see how much was being used up inbetween water changes (i got worried when i saw PH always hitting 8.6). I do have very slow growth on my zoanthids and i'm sure that is because of my low ALK.

I am just started dosing for alk again and am going to just completely ignore my ph and slowly get that alk up. I'm not going to be raising the number very fast so as long as the corals / fish / inverts all look happy then i'm not going to sweat the ph.

Also I never got around to recalibrating the PH probe so also going to get that done this weekend. Hopefully it is just reading high.

Plan on getting a Mag test kit to make sure that is in the right range, may be that is low and why i can't keep my alk up? Calcium seems to barely get used up. I also was thinking Calcium might get used up more if my alk was higher? I don't have SPS's, but doesn't coraline use it?

 

[Jeremiah]

[attachment=65268:name]Pics of the marks, thoughts?

 

[Jeremiah]

Isn't alk 6-7 a bit low?

so I got my alk up in the 8+ range since you mentioned it and those spots are fading...almost all gone. Also coralline is growing like crazy. My guess was the black spots was the coralline dying.

just wanted to give an update...

 

[Andrew_bram]

Are you sure it's not flatworms. Hard to tell in the pick but it does resemble those. Take a very small piece and just put part of it in fresh water so you don't kill the whole piece of rock. They will come right off if that's what it is.

 

[Jeremiah]

Yup I am sure the spots are not flatworms. When I started noticing those I had also noticed that the coralline has stopped...my alk had gotten as low as 5.

 

[Andrew_bram]

Sorry just wanted to throw it out there I have seen people mistake flatworms for diatoms.