Algae Blenny food

[Van down by the river]

Hello Scott,

Well your first problem is simply this, the tank is too small for your Blenny.
You said "Nano" so I will assume your tank is less than 20gallons. Normally a Algae Blenny is recommended for 50 gallons or larger. Your clown and Royal Gramma are omnivorous (unspecialized) feeders and will eat practically anything. Although your blenny may eat meaty foods, and they often do, it is not his main natural diet. You may find he bothers your corals when he has a lack of natural food supply. You mentioned algae wafers, if you are referring to the hard types of discs and pellets you will find that only larger fish such as Tangs will show interest in them.

Rich's suggestion of seaweed attached to rocks is a good idea that I have used in the past. It has been my personal experience that these blennies have a high metabolism and can require large amounts of suitable algae to fulfil their dietary requirements.

I would also like to draw your attention to your hair algae problem in your aquarium.
I think a more productive long term solution would have been to focus on your water chemistry. The addition of another fish increasing the bio load will only serve to further aggravate the hair algae problem, as even the current nutrient levels are not being processed effectively.
Revisiting some of your maintenance/feeding methods may also help you control your algae problems.
You mentioned your clown and Royal gramma are fat and happy. Remember that even if your fish eat all the food given they only process a certain percentage and the rest is past on back in to your aquarium as waste (also know as Algae fertilizer). So maybe cut back slightly on your feeding to reduce the nutrients available to the algae.

The addition of various small grazers such as hermits and snails would have been a much better solution for a small tank. They also will have a much smaller effect on your bio load.

Blennies have pretty small throats comparatively.. They have problems eating many things.- Rikko

Although somewhat true, I think you would be surprised at what small fish are able to swallow. I do agree that variety in food and particle size is beneficial. Obviously within reason, the ability to swallow has some effect. Some fish will show prey size preference, but I don't think that's the issue here. Usually what is referred to as a Algae blenny is a Salarias fasciatus, Istiblennius sp. or closely related species with about a 10 -15mm mouth opening.


quote]Maybe try growing some grape or feather caulerpa, since most herbivores love that stuff. If I toss in a fist sized clump in the evening, by morning not a stem is left after my tangs & angels are through.-SeaHorse Fanatic/Anthony[/quote]

Caulerpa's may help with reduction of nutrients in this case, but due to the small size of the aquarium and risks of macro algae reproduction. I don't think this is the solution.
The blenny has a comb like mouth designed to scrape small algae off the rocks. Unlike larger herbivores he will most likely show no interest whatsoever in large Macro algae.

So what is the solution? based on your post:

I got a small Algae Blenny for my Nano about 6 weeks ago and it has been doing an amazing job with hair algae in my tank. It is constantly active picking away at the glass and rocks. I would have expected it to be fat by now but it is not. In fact it appears to be slowly wasting away.

Look at some of the issues I mentioned.
As for the blenny, it is in his best interest that you place him in a more suitable home. It is quite obvious that he is not getting enough to eat. Trade him back to the store you got him from for snails and hermits. If you are unable to do that than sell or give him to a fellow hobbyist with a larger more suitable aquarium. If you choose to keep him, he will ultimately waste away and die in your system. Please be responsible, they are living things.

I hope I've helped clarify things, and do not take any of this as a personal attack on you or anyone else's abilities or ethics.

I do think that asking questions prior to purchasing would have avoided this.