Any Guess To What These Are?

[Seige]

Just an update, I had a tank meltdown in November and lost everything because of medicating for cyanobacteria. So I took all my LR and scrubbed it down, rinsed it off and propane torched the colonies of these Hydroids. Been almost 3 months now since that, and I still have a few small returning colonies in those hard to get places, but because I am still in the process of rebuilding my stock I can easily take the piece of rock out and torch the colony again, problem is that kills all the coraline on the rock too, so I have to wait till the coraline starts to reappear on those treated rocks. I may try the hot water squirt, but these are very resilient, having reappeared after being on rock that dried overnight, was propane torched, and survived the meltdown of my tank when all my levels skyrocketed past the highest levels my test kit could show. The meds killed out my nautural filter bacteria in the whole tank, thus the tank was not able to support the live stock, and further more as animals began to die they only added to the chaos. Aptaisia treatments didn't appear to help, such as Joes Juice. The torch option works, but you may have to re-torch those areas that are very dense.

Sorry to hear about your meltdown. That must have been rough and costly. Hopefully you have reef clubs in your area that helped you restock.

I've got 3 fairly large aptasia I need to deal with soon. I'll probably try the juice/syringe method this time since they are larger.

[Ninong]

If you have only a few Aiptasia, get a large syringe and inject them with plain white vinegar. It won't harm your tank at all. If you tried to do that with a lot of them at one time, you could lower your pH but you won't if you just do a few.

[Ninong]

As far as I know, there is nothing you can use against Cyanobacteria that is both effective and safe for use in a reef aquarium. Some of those products contain Erythromycin, an antibiotic. After all, if the product kills bacteria (Cyanobacteria), then it's bound to affect other bacteria in your system, especially if it is accidentally overdosed.

Eliminate the causes of the Cyanobacteria, otherwise it will just come back a few weeks later anyway.



P.S. -- Cyanobacteria has been discussed in detail in many, many previous threads over the past ten years.