when i just did my change from gravel to sand i removed the ugf that i had stopped using months ago and my tank got so nasty and cloudy because of all the "stuff" underneath it im amazed that i didnt have huge spikes in my water params, but i did 2 80 percent water changes in 2 days and it is almost back to norm, it is only a little cloudy but im guessing that it is also from the sand i put in as well. so i dont highly recomend ugf's. it never did anything for my tank anyways, thats why i stopped using it.
(BTW none of the posts i read warned me to wear gloves when rinsing the sand and my hands got dyed black and my knuckes got so torn up that it looked like i had beaten someone up lol)
(BTW none of the posts i read warned me to wear gloves when rinsing the sand and my hands got dyed black and my knuckes got so torn up that it looked like i had beaten someone up lol)