Long term update, silicon did not work to hold them, finally used pvc glue it works well. They are in quar. tanks now and in one customers tank now. working well still. Very nice item for the price. Would have to say recomended if you are going to run power heads in your tank. Might be really nice with that dual outlet power head the lady is selling on here right now. Steve
I think my problem is they are on aquaclears 802 that are supposed to pump 400 gph. LOL I dont think they like it very much. I think if I had siloconed them from the start I would of never had any problems at all. I think the biggest maxi is rated to what 290-300 gph? I have never tried them but I hear always good things about them. Steve