that really sux, i just bought a similar set up, MH and HPS ballast, and i am currently running the MH for the last week or so, I hope I dont run into the same problem at day 23 or near, thanks for the heads up, but if i did, I agree with those who say to throw the HPS in, everything I have seen says you can use it to go straight thru veg to flower anyway so it cant hurt for a day... and I hate cfls lol, i dont get em... but I am a newb who never tried em...