Sick algae blenny?

hi, I'm new to this hobby having set up my marine tank in feb 2010. I have had an algae blenny for about 1 and a half months now and he/she is looking & acting abit strange. He/she has always been very lively up until this morning when i noticed it was lying in the corner of my tank where there was no hiding places and it hasn't moved since, one if its eyes seems to have gone abit cloudy and red and it seems to loose its colour every now and then. I have had a few other deaths in the family since then... 2 blue/green chromis, 2 clownfish, 2 cleaner shrimp and I lost a six line wrasse just this morning.
my tank parameters are 0 ammonia, 0 nitrite, 8.4 PH and salinity of 1.022 but the nitrate is between 20 and 40, i realise this is high but no matter how many water changes I do it doesnt get any lower! I asked at my local pet shop and they said that the nitrate isn't as important as the rest as all it will do is create more algae.
Not sure what is going on so all advice is greatly appreciated!!

 

Does your tank have enough algae for the blenny? Is he eating? If his belly is really really thin, he might be in trouble. Try nori algae sheet.

 

yeah he's been eating great, there is loads of brown algae on the rocks, that is ok for him isn't it? or is it another type he eats? his belly seems ok to me, look no different to the ones in the pet shops. don't understand whats happened.

 

It seems to me your tank is still very new to have been that heavily stocked, I don't know what is wrong with your blenny by the description.... can you post pics?

More tank info also would help.... how much LR? What size tank? How many fish do you still have? What did you introduce last?

Try to think of anything that has happened/changed in the last 2 weeks, have you added anything new? Dosed anything new?

 

I can't think of a single brown algae they would eat. I'm not saying that's the cause.....they just normally eat green and red algaes.

 

I have pictures but for some reason can't upload any.
my tank is 140 litres and i think there is approx 12 kgs live rock. at the moment it has 4 blue/green chromis, 2 clownfish, 2 firefish, 4 humbug damsels, 1 bangaii cardinal.
We introduced the 2 clownfish a few days ago.
There is a little green algae on the glass and a little on the rocks, but i have never seen him eating that before only seen him eat the brown algae.

 

Also quite a few of the fish seem to be rubbing themselves on the rocks, i believe this is Ich? we have treated them using something called "oodinex" but havent been very succesful

 

Ok, first off... stop adding fish!! This isn't helping any

I need to convert your liters into gallons and then will repost. Brb

 

Think it is about 35 gallons

 

You are correct, its around 35 gallons.

Ok, first step is to stop adding fish, for a 35 gallon tank there are wayy to many fish in there. That is a big part of the problem IMO....

There could be some sort of parasite or something (say this because of the rubbing on rocks) or it could be ich... either way it needs to be dealt with.

My advise would be to research and find out exactly what your problem is..... as far as the blenny, it could just be stressed because there isn't a lot of room in the tank, or oit could be getting bullied. Then again it could be affected by the same "thing" your other fish are (the ones iching on the rocks).

Hope I helped, and I didn't mean to sound short in the last post.... I'm sorry