The curios case of the disappearing GHA

[jda]

There is a tuxeudo urchin in one of those photos. Those things destroy soft algae in time. Often it looks like they are not making a dent and then they seem to matter in an exponential way.

As tanks mature and the urchins eat the ground clean, other things can help colonize behind the urchins.

The tuxedos only live like 2-3 years, so have a plan to replace them.

 

[jda]

IME - without herbivores, if you have corals thriving, algae can thrive too. Starve one and stave the other. The herbivores are the difference.

The exception to this is algaecides, or algaecides that were sold as bacteria supplements like Vibrant.

 

[arking_mark]

IME - without herbivores, if you have corals thriving, algae can thrive too. Starve one and stave the other. The herbivores are the difference.

The exception to this is algaecides, or algaecides that were sold as bacteria supplements like Vibrant.

When replenishing/increasing my herbivores...I did not see any difference in reduction in GHA for 9 months. The GHA was never terrible or overtaking my tank, so they were probably keeping it in check...and once the GHA started to reduce the herbivores definitely finished it off.

I really feel something has changed in the tank and agree with @Randy Holmes-Farley that either or both:

1. Something it depends on has become very limited (nutrients or elements/ions)
2. The biome of the tank has changed with something that is out-competing the GHA

Along with the disappearance of the GHA, my Zoas disappeared.

As a quick experiment, I added a small colony of Rastas (40+ heads). It almost completely receded in a week. So I’m leaning towards something important to them being limited. Not sure what as my ICP tests are pretty clean.

 

[jda]

I would have zoas melt when I had not changed water in too long - simple water change kept them better. Not all zoas, but some. Traces, most likely.

Have you been changing water?

ICP cannot test for everything and does not test for compounds. It is mostly useless to me. I spent the money on salt instead. For example, you could have enough Vibranium in the ICP test which sees the element, but it might not be in vibranium tri-poly-chloride form which corals use and was in some other form like vibranium phophate which is useless to corals.

The urchins can often look like they are not doing much and then the removal speeds up like crazy...

 

[arking_mark]

I would have zoas melt when I had not changed water in too long - simple water change kept them better. Not all zoas, but some. Traces, most likely.

Have you been changing water?

ICP cannot test for everything and does not test for compounds. It is mostly useless to me. I spent the money on salt instead. For example, you could have enough Vibranium in the ICP test which sees the element, but it might not be in vibranium tri-poly-chloride form which corals use and was in some other form like vibranium phophate which is useless to corals.

The urchins can often look like they are not doing much and then the removal speeds up like crazy...

Automated 1% daily water change.

 

[jda]

Look for a nudibranch or snail munching on the zoas at night.

 

[arking_mark]

Look for a nudibranch or snail munching on the zoas at night.

...only thing left is my Grandys Palys. So not sure I'll find anything at night.

 

[Court_Appointed_Hypeman]

...only thing left is my Grandys Palys. So not sure I'll find anything at night.
[/QUOTE]
Might be worth doing less frequent larger water changes. Can your awc system do 20% every 20 days instead? Obviously it depends on your reservior and waste sizes to keep it practical amd worry free, but smaller more frequent doesn't dilute as much.

Unless you already do some water changes on top of your auto.

However, I never change water anyway, so I am just throwing this out there.

 

[Gretchacha]

In one week:

To....

Perhaps they need more nutrients and iodine. If they came from a more nutrient rich tank, they could quickly decline in the new environment, but could be trained to be in a low nutrient system over time.

 

[arking_mark]

Perhaps they need more nutrients and iodine. If they came from a more nutrient rich tank, they could quickly decline in the new environment, but could be trained to be in a low nutrient system over time.

That could be true. My tank has almost always run ULN...at least measurable PO4 and NO3. However, I try to be heavy in heavy out with my tank.

The Zoas did come from a much higher PO4/NO3 tank...so that could certainly be a possibility.