I just completed a full set of six blankets and a dozen burp cloths for a baby present. The tension was a little off but I continued with the project because it did not negatively impact the overall project. I switched out the threads so that I could adjust the tension before starting another project. I had purchased a multicolor set of thread...red...blue...yellow...and green just for the purpose of learning and troubleshooting. Wouldn't you know... now the tension is good. The rethreading must have reset the threads in the tension discs so that the overall tension did not need additional adjustments.
Luckily, my multicolor threads were more pastel...pink...light aqua...light yellow...and spring green... so the serger will work as threaded for baby blankets.