Yellow in corals

I have a 3 month old tank, my corals are doing well, good colors and growing. I keep PO4 as low as possible. .03 or less. ULR Hanna.
My NO3 stays around 3ppm.
ALK 9.5
Cal 430
Mag 1350

I have high flow, 60 times display.
High light, Kessil AP700
Some frags I have are a little slow getting started and a bit pale.
I have a good amount of fish some lots of nutrients going in.
Strong skimming SRO-5000, refugium/cheato, vinegar dosing, GFO/Carbon, MarinePure Block.
My parameters stay rock solid, I test ALK often. Use Kalk in my ATO, two part ready once Kalk no longer fullfls demand. PH averages 8.25 some times higher.

I feel like I have everything needed and the stability is there. I guess all I can do is keep it up and hope for the best.

That all looks good.
You have a FTS of that amazing reef?
 
I've also found that maintaining a proper K level seems to benefit the overall color of every stick. (not just blue)

I also can't say that it's directly linked to yellow but I do know that overdosing Potassium will certainly show in your yellows... I had a K level of 460 upon returning from Europe over the summer and my Wolverine colony looked like a neon yellow/green glowstick. By letting it naturally drop down to 420, it brought back more of a true yellow in the coralites.
 
Last edited:
For me its a balance of elements and nutrients with optimum flow and high light. I observed to make yellow or to keep yellow you need to keep your nitrate low <2ppm if it goes up then the yellow started to become greenish yellow. In case you run too low NO3 like 0ppm it become pastel yellow like we see in zeovit and other ULNS systems.
 
I've also found that maintaining a proper K level seems to benefit the overall color of every stick. (not just blue)

I also can't say that it's directly linked to yellow but I do know that overdosing Potassium will certainly show in your yellows... I had a K level of 460 upon returning from Europe over the summer and my Wolverine colony looked like a neon yellow/green glowstick. By letting it naturally drop down to 420, it brought back more of a true yellow in the coralites.

How quickly is your K used up, how much do you need to does to keep NSW levels
 
That all looks good.
You have a FTS of that amazing reef?

IMG_2707.JPG


I've got about 60 young corals in there. My iPhone just isn't really capable of getting good shoots.
 
I think in many ways it is only certain corals that are going to be actually yellow. In almost all occasions the yellow is tinged with green or tan. I have had a lot of acros through my system, this is currently the only one I have seen that is truly yellow in my tank. I have it high in the tank under MH lights, with strong flow. Nitrates are at 5-8 ppm, Phosphates around 0.05 ppm.

_D712088.jpg
 
How quickly is your K used up, how much do you need to does to keep NSW levels


Take my Potassium post with a grain of salt. I know of plenty of tanks that don't dose/test for Potassium but still pull brilliant yellows like no other. Maintaining Potassium within a range of 380-420 ppm is sufficient. Potassium has a low-moderate consumption rate which is somewhat comparable to that of Calcium, but not quite as fast.

With the current lack of continuous research and proven knowledge supporting the roles that Potassium plays in the reef tank, it's hard to fully give it credit for anything other than the direct impact it has on the health/coloration of Montipora species, along with it's ability to target and enhance blue color pigmentation of other SPS species.

IMHO I truly do believe that Potassium is equally as important as Magnesium if not immediately trailing behind it. However, that's solely based off of my own personal observations upon maintaining the desired K level in my own system.


In conclusion, I know that time alone along with many other factors play a significant role as well. But at the end of the day, when I gaze into my display and don't see a tank full of brown, gray or bleached coral, I know I must be doing something right... ;)
 
Last edited:
I think in many ways it is only certain corals that are going to be actually yellow. In almost all occasions the yellow is tinged with green or tan. I have had a lot of acros through my system, this is currently the only one I have seen that is truly yellow in my tank. I have it high in the tank under MH lights, with strong flow. Nitrates are at 5-8 ppm, Phosphates around 0.05 ppm.

_D712088.jpg

That contrast is simply amazing! The purple coralites of the colony in the foreground perfectly complements the yellow behind it. Looking good :D
 
Interesting perspective, the good doctor says most (acro) are yellow due to stress

http://www.advancedaquarist.com/blog/be-cautious-of-yellow-acropora
He actually says that some staghorn acros turn yellow a few days before they die.

"
When staghorn corals bleach, they sometimes fluoresce a bright yellow colour, as seen on several reefs this year. This may help the coral to defend itself against damaging ultraviolet radiation from the sun. This phenomenon lasts for several days, after which the coral usually dies.

Should you encounter such a bright yellow Acropora at your local fish store, be sure to ask your vendor if this is a recently imported specimen. If it is, it may not last very long."
 
I have a 3 month old tank, my corals are doing well, good colors and growing. I keep PO4 as low as possible. .03 or less. ULR Hanna.
My NO3 stays around 3ppm.
ALK 9.5
Cal 430
Mag 1350

I have high flow, 60 times display.
High light, Kessil AP700
Some frags I have are a little slow getting started and a bit pale.
I have a good amount of fish some lots of nutrients going in.
Strong skimming SRO-5000, refugium/cheato, vinegar dosing, GFO/Carbon, MarinePure Block.
My parameters stay rock solid, I test ALK often. Use Kalk in my ATO, two part ready once Kalk no longer fullfls demand. PH averages 8.25 some times higher.

I feel like I have everything needed and the stability is there. I guess all I can do is keep it up and hope for the best.
As a fellow Ap700 owner, just be patient. It isn't until about month 6 where your tank "matures" and your corals start growing like crazy. If you're 3 months in and aren't having trouble keeping SPS alive, then I think you're ahead of the game. :)
 
Does anyone have examples of yellow acro's turning green? I've browned and bleached them but never green. My guess is bleached/morphed green acro's are being sold as yellow. I have only seen 3-4 acro species that are true yellow.

I also don't believe you need any fancy parameters to keep yellow acro's. Proper lighting and stable sps parameters. For nutrients I run 0.00 po4 and 0ish nitrates. I also feed 8 cubes of frozen, flake, and reef energy daily.
 
Well you don't need fancy parameters but parameters such as yours help acros with a greenish hue to show more yellow. I agree there aren't a lot of yellow acros but there are a lot with a greenish hue that with the right situation you can make look fairly yellow.
I don't really believe you need to be careful of yellow corals dying that are recently imported at all. You just need to understand what certain acros are supposed to look like and understand all the elements of stress that can happen when wild or maricultures are shipped. Along with how to deal with them when a certain sign is apparent on an acro that has arrived.
 
Very interesting Discussion. I don't have very consistent observations but some acros that were sold to me as yellow-green were mucho more greener when placed at relatively low light than when placed at the top of the tank.

Anyway I think it would be valuable for the progress of the Discussion to indicate the species of Acropora we are talking about. In that way we could ascertain which ones are truly yellow and which ones are green that may show some yellow.
 
Very interesting Discussion. I don't have very consistent observations but some acros that were sold to me as yellow-green were mucho more greener when placed at relatively low light than when placed at the top of the tank.

Anyway I think it would be valuable for the progress of the Discussion to indicate the species of Acropora we are talking about. In that way we could ascertain which ones are truly yellow and which ones are green that may show some yellow.

I think we in majority talking proven acro's only here.
Acro's that you know of from their linage that are yellow.
Getting just a acro yellow that is bought as a green hulk will be a tough call.
Know for the yellows is that they need high in the tank with lots of light.
If you can blast a par of 400 at your sand or middle up that's great but at the same time we looking at 500 close to 700 over the top of your rock in the higher areas, not much corals will be your friend if so.
And IMO not a whole lot of fixtures will give you that much par and still look good to the eye.
 
As a fellow Ap700 owner, just be patient. It isn't until about month 6 where your tank "matures" and your corals start growing like crazy. If you're 3 months in and aren't having trouble keeping SPS alive, then I think you're ahead of the game. :)

Thank you. When you have put so much thought and effort into a system you often question things. I guess your right and should be happy with my progress. I can't help but look and question everything.

IMG_2836.JPG
 

IF YOU HAD TO TAKE A REEFING EXAM, WOULD YOU PASS?

  • Yes!

    Votes: 32 45.7%
  • Not yet, but I have one that I want to buy in mind!

    Votes: 9 12.9%
  • No.

    Votes: 26 37.1%
  • Other (please explain).

    Votes: 3 4.3%
Back
Top