Too much Nori?

adidas · #1 07-25-2006, 03:40 AM

I've got a nice healthy 4" sailfin Tang, he eats a 2"x2" sheet of nori in the morning and could easily eat another sheet before bed.

How much is Too much?

Delphinus · #2 07-25-2006, 04:21 PM

I would define "too much" as the point when your tank starts having problems from overfeeding. Problem is, as far as the fish is concerned, you can't overfeed them, they're always hungry. And in the ocean where the food supply is more or less infinite (maybe in smaller doses, but basically they eat all day), tangs are 4 to 5 times as fat as the fattest fish you ever saw in an aquarium.

So the trick is finding the balance of not trying to restrict the feeding too much, without cratering your system in the process.

Depending on the tank size and bioload buffering ability of your system, I'd consider two 2x2 pieces, if I could swing it. (I personally can't do that in my own system, I feed about a 2.5x4 sheet once per day, and occasionally twice as a treat). Like I said, you have to find the balance. Keeping the fish too hungry is cruel, but so is keeping the fish in a nitrate soup (my $.02 anyhow).

EmilyB · #3 07-26-2006, 08:39 AM

Fish don't mind nitrates, it's phosphate that will affect them. I haven't really measured what nori does in that regard but it might be interesting.

Delphinus · #4 07-26-2006, 03:59 PM

Welllll ... OK. Fish may not mind nitrates directly, but the fact is if you have too many in your system there will be unpleasant consequences nonetheless, it is better to avoid a buildup, which was the point I was trying to make. Also I sort of used the term "nitrate soup" simply as an analog of "water with a high dissolved organic compound" which realistically will include other byproducts/endproducts/whatever besides only nitrate.

Nori does seem to introduce phosphates as well:
http://canreef.com/vbulletin/showthread.php?t=12625&

I guess the point I was trying to make is that if you find your tank system in unable to cope with the bioload of the fish being fed, that it is an indication that things may need to be adjusted or upgraded (larger tank, more LR, stronger skimming .. whatever ..). One needs to take a balanced approach.

adidas · #5 07-26-2006, 08:22 PM

thanks!

yup i've been trying to keep my Sailfin eating like a pig. i usually put the nori in and make sure he eats it all, so nothing left to create nutrients. I'm really careful with flake and shrimp not to overfeed the tank.

so i guess the only concern with a lot of feedings is the effect it can have on the bioload.

christyf5 · #6 07-26-2006, 08:39 PM

I feed my fish a 3"x2" chunk daily (3 of them eat nori), I can't believe the amount of crap it generates on the bottom of the tank. Because of this I have to do water changes weekly to siphon it all up as it forms piles on the bottom of the tank that start to deteriorate as well as look gross. This week I experimented with not feeding nori at all, just frozen as usual and the lack of detritius on the bottom of the tank is incredible. However my fish are getting lumpy guts so its back to the nori I go. In the meantime, they certainly do pick at the rocks more without the nori (eat that damned algae you picky little buggers!!

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