The aiptasia dilemma; what do I really have?

[jonzer]

I don't want to bore everybody with the same question, everybody else asks, but I think I have aiptasia, but need a little clarification:

 

I actually have 2 critters climbing around. And the only reason I ask is that they look very different, but I have seen pictures here of BOTH and both are claimed to be aiptasia! So here goes (my camera just doesnt get a good pic):

 

Critter 1: approx 1/2" diameter and 1" tall. Nearly opaque brown with a stem and 1/2" tantacles. This looks very 'anenome-like' and I'm pretty sure this is the aiptasia. Looks like:

http://www.nano-reef.com/forums/showthread...&threadid=36772

 

Critter 2: total diameter is about 1/16." They are flat and have an opaque white center, with radiant translucent tentacles. Unless my eyes decieve me, the tentacles are translucent and opaqe white striped. These have just recently infested my tank. They are on the glass, on the LR, on the hermit crabs and snails (thousands of them). They just recently appeared after the addition of a banded serpant star and a 20% water change w/ distilled water/instant ocean. Looks like:

http://www.nano-reef.com/forums/showthread...&threadid=36685

 

Any help distinguishing these two creatures is greatly appreciated. BTW, water is pretty much flawless. Ni, Na, Am at 0, pH at 8.3, sg at 1.0235, temp at 79F. I recently had been dosing with kalkwasser for corraline growth, but had stopped about 2 weeks prior to the appearance of these guys. Again, the only reason I ask is that both have been deemed aiptasia, but they look completely different.

 

Thanks again in advance!

[ODOG]

#1 is probably aiptasia, I had a few on one rock...tried tweezers with no luck so I bought 2 peppermint shrimp and they ate them by the next morning.

#2...what you describe and the picture aren't the same in my opinion. I have something like your picture on a rock. He can retract into a hole in the rock or into himself, i'm not sure. What you describe sounds like hydroids which are jellyfish. They are harmless. They tend to show up on the glass every now and then. If you can, squirt one off and watch him swim around the tank...it's pretty entertaining.

[jonzer]

thanks for the input, I feel like I finally have some clearification, now:)