In the past few months i have put in two diff. blennies. Both have died and then i think my brittle star has consumed them. Are brittle stars and blennies not compatable??
Also i lost my emerald crab. I think he may have just been old.
My water params are good. amm. 0% nitrite 0% and nitrate 15% or so.
Any ideas here ??? TIA.

I have also noticed that i have what appear to be small white tube worms. There are hundreds of them. They are on the live rock and in my sump. Has anyone experienced this?

Are they like tube worms on your glass? If so then yes.

In the sump they are on the glass. In the main tank they seem to stay on the rock.

I assume that they are good and not bad ??

Yea, they arent vad. I have alot in my overflow sump. Nothing to it. Just that they can get annoying when theres alot.

Were both the fish healthy when first introduced and were they eating? Also what species of Blennies were they? What other fish do you have in the tank? The Starfish may have killed them, but not very likely. Tube Worms are harmless, I have had them in all my tanks.

They were sailfin blenny i think. And they were healthy when i put them in. The last one lasted for about two weeks then just disappeared.
Other fish two green chromis, one coral beauty, one yellow tail damsel, one yellow tang, two cleaner shrimp, one brittle star. And some polyps and the condy.

I had a similar experience with a scooter blennie. I finally caught the culprit in the act after he had killed 2 other fish... it was my scarlet skunk cleaner shrimp. No, I'm not kidding, I wish I was. I actually watched him as he plucked a perfectly healthy fish out of the water, and began consuming it tail first until it was dead, otherwise I would have never believed it myself. As beautiful as they are, I don't think I'll ever get another skarlet skunk cleaner shrimp... it's peppermint shrimp for me from now on.

PS - The remaining fish exacted revenge when he molted from all that eating, and I havn't lost a fish since.

Well my cleaner shrimp are the skunk ones but i have never seen them bother anything. Both of them are quite large, so i guess they could kill a blenny.

They arn't supposed to bother anything, in fact they are supposed to be benefitial. I thought my experience was unique, but now I'm thinking otherwise.