Will Chaeto survive?

I recently put my 75 gal reef tank back up after a few years and it is mid cycle. Ammonia is down now but nitrites are still elevated and nitrates are off the charts high. I need to make a trip to get some water from my lfs but its about 40 mins away(I am planning on my own RO/DI unit soon). I was hoping to be able to get some chaeto for my refugium while I'm there but I wasn't sure if these levels might kill it. I know it consumes nitrate but mine is sooo high. I don't want to interrupt the cycle by changing water before nitrites drop and the lfs is only open Fri sat and sun so I was going to get the water to have it on hand. If I can I'd like to avoid a second trip for a $10 bag of macroalgae.

 

It's $10, probably worth the try just to save the gas, but I'd guess it'll thrive!

 

It is interesting that chaeto will grow like a weed for some people, then for me it continually dies... What I learned is that the right light is of utmost importance...for photosynthesis to work well, light in the 6500k range in important...all of the "refugium" lights I purchased in the past have not encouraged the chaeto. Once I purchased a simple clip on, metal shaded light fixture and a 75 watt 6500 k flood light, placed this on a timer to run 12 hours a day, the cheato took off and in the last 4 months has increased 10 fold in size. If it keeps this up, I'll soon be listing some for sale...