Hey folks been away a while on vacation just wanted to make contact again. All is pretty good with the tank,anybody want pulsating xenia

this stuff is a weed been growing and spreading like crazy. Moved rock around to isolate from rest of the tank (right). Do have a question although our pink birdsneat which has been growing well has developed some brown tips

I have seen crabs tangled up in it and wonder if this could be the cause ? or is it somrthing else params are on the money and every thing appears normal except for the brown tips any thoughts that can help me clear up this concern ?