Urry88

Just found these worm like things in my sons shrimp tank today not sure what they're but read it may be planaria and advice would be appreciated. I water change once a week, feed every couple of days and syphon the excess food out the tank a little while later. I've also not added anything new to the tank and did a big water change and cleaned the substrate about 2 weeks ago they've only appeared today so not sure where or how they got there. Also I have 2 little cherry 2 big clear ones and a little clear one and one of the big shrimp has eggs.