Tiny yellow worm on zoas, water chemistry

[Rapture111]

Hi, this is my first salt tank and my first coral. The tank was running for a long time (years) with only live rock. I thought I was going to upgrade the lights to LED (tank is a Biocube 8), but finally just put new bulbs in. I drained the tank and moved it downstairs, then put the same water back in. It had some ammonia, no nitrites, and some nitrates. While I was waiting for the ammonia to cycle out (about a month), I then moved into a new house. The tank was drained down to a couple of inches for the move, and sat that way for 3 days. I refilled with new salt water. Today my aquarium club had a fish meeting, and I meant to test the water before going to the meeting, but I forgot since I was still moving things from the old house. At the meeting, I bought a small zoa frag. When I got home, I tested the tank water, and it had some ammonia, lots of nitrite, and a lot of nitrate as well. I had about 1 gallon of clean salt water left in the jug, so I changed that much water. I also added 5x Prime. I figured the zoas would not even open and just die, but they are opening quite quickly. I noticed a couple of threadlike, yellow worms living in them. I tried sucking one out with a syringe, but all I managed to do was make the zoas retract. Do I need to worry about these worms? Seeing them reminded me that I haven't learned to dip corals yet. As for the water parameters, I was planning on getting more salt water tomorrow and continuing to change water while the tank continues cycling.

[RayWhisperer]

Look up spaghetti worm. It sounds like that's what you've got. If so, it's not a pest.

[MainelyReefer]

Are you sure it was worms and not the insides of the zoas coming out?  When my softies get upset or hungry that happens, mostly with mushroom corals they will let out what looks like intestines, I have seen it on palys and zoas before too perhaps that's the case? Do you have a picture? 

[Rapture111]

Thanks, I think it looked like the little legs of the spaghetti worm. I did not catch it in any pics. The zoas are still seemingly doing very well. I have changed 12% of the water two days in a row so far. Someone mentioned that I should change water less often. I'm just worried about the parameters being so bad. I am still overdosing Prime when putting in the new water.