Do I need THAT much live rock

[musicman980]

I was in my lfs the other day and asked about fish to live rock ratio, the guy said that the 5 to 6 lbs of live rock in my 35 long tank was enough to keep a clownfish in it, cause any more rock would just die off.
I went in there days after and spoke to a different person and he said that i need 30 more pounds of live rock to get another small clownfish.
Do I really need 35 pounds of live rock to keep 2 clownfish? Because hypothetically speaking for exaggeration, if I had a 150 gallon tank with one goby I wouldnt need 150 pounds of live rock, am I right?

 

[novahobbies]

There's not really a single answer to your question, and your hypothetical doesn't exactly relate to your situation. You're right; a 150 gallon tank would not need 150 lbs of live rock to filter the waste of a single goby. The hypothetical question is one of dilution, really: a single goby will take a LOT longer to "pollute" a 150 gallon tank, whereas 2 clownfish in a 35 gallon tank will pollute the tank a whole lot faster!

 
In regards to your immediate problem, I think you can split the difference between the two extremes if all you ever intend on keeping is 2 clownfish. If you decided to add more fish, however, or add coral, then yes - a minimum of 30 lbs would be recommended. As it is, I think you could easily use 15 to 20 lbs of rock to provide plenty of surface area for biological filtration to handle your two clownfishes waste. IMO 5-6 lbs won't really be enough.

 

[musicman980]

Well my nitrate level has hovered at 30 to 40 ppm for the longest time with 1 clownfish and 5 to 6 pounds of live fiji rock, and that is acceptable because my clownfish is very happy. Wouldnt like 10 to 12 pounds be enough? Would there be an ammonia spike or something if I got the new fish and didnt put any more live rock in?

 

[flower]

 
 
Live rock serves many purposes besides natural filtration. Saltwater fish need a place to hide and feel safe. Fish nip and feed on the little critters that live in and on the rock. From what I have seen, most successful reef keepers have the rock half way up the tank. Leave lots of crevices and small caves so the fish can swim in and around it.
Leave open areas so the fish can just swim unhindered as well. Clown fish are not all that active and stay in a corner or host a coral, anemone or intake and output tubes for the most part. They still look for food on and in the rocks.