I have two pairs of kribensis in my 55 gal tank. One pair had about thirty fry a month ago which have grown to about 1/3 inch in length and have been reduced in number to about 20 by being picked off by my rainbowfish when they were tiny. Now the same pair has laid eggs again and is preparing for the next batch! Should l let them go through with it? The mother is already chasing away her last batch to protect her nest. This is my first time having babies so any ideas would be appreciated. How long do you wait to sell the fry?