Just want to thank ereryone here for the great info,that allowed me to sucessfully set up my 20gal long.Planned ahead for 2 mo. befor setting up.I have 1-55 wt.6700k ah supply retro. and 2 13wt.retro.Can say only goor things about ah.super products and price.Also have Hagan co2 system doin good job,have to prune plants every week.Have 6 amano shrimp.8neons,3 ottos,2 sae,2 dwarf garamies,sorry cant spell sometimes.Plants include.glasso.val,indica,2 red plants.Ammonia 0,ph-6.6-7.0 late afternoon.nit-0 do 25%water change weekly.dose florish twice a week-half a capfull,and excell every other day,half cap.used 10lbs.shults on bottom 12lbs flourite on top,is all about correct?again thank you,and any suggestions ,ps been set up for 6 weeks now no algee prob yet,knocking on wood. ha ha