Since you are pooling, I consider that you are interested only about qualitative assessment of the metagenome. In this case, my suggestion is to quantify each of the sample by nanodrop or Qubit and make pool by taking equal amount (ng/ul) of DNA from each sample. Calculate the amount of each sample to be added in a way that the concentration and total amount required for the sequencing is met. Hope this works.

best wishes,

SD

thank you dear..

Look into barcoding the samples before combining them. You should be able to pull based on just the concentration after that as Sibnarayan Datta said.