Increased nitrite in QT
 

So I have a 10gal QT with a sponge and ceramic bio cylinder type material in the filter (was running a week or so in my DT so help jump start the bacteria prior to putting it on my QT). I test my water daily and cycled tank with water from my DT. Water changes done weekly with freshly mixed water. About a week or so after setting up purchased chromis, a firefish and a diamond goby. Only lost one chromis to abuse? Otherwise the rest look well. I noticed end of last week my nitrite levels have been increasing but everything else remains good.
Temp:74, sal:1.025, kh: 8, ca:360, no3:0, ph:8.4, PO:0, nh:0
I was doing 10% changes daily which did nothing and then started doing 50% daily still with no major drop. I feed once a day of flake food. Tank is all glass with a few plastic pipe pieces that was boiled to sterilize. Anyone have any tips to help reduce my nitrite? After my water change (50%) I got 0.25. Help?

If there was no change at all after a 50% change, I'd try another test kit.

Also if you're talking about nitrite then it's probally cycling, since you should only be reading nitrate with fish in the qt. I believe nitrite is not good for fish. You should run a hob filter to help speed the cycle.

Yeah I am currently running a AC30 with the carbon removed and just the foam and the bio ceramic type material. Had it running on my DT for a week prior to putting it on my QT. will go grab a new test kit and see what my reading comes back at. Until then, daily 1-5g changes

I wouldn't worry about nitrite or nitrate in a fish only QT. Nitrite/Nitrate are not toxic to marine fish unless the level is very high(>100ppm).
IMO you should monitor ammonia regularly in a QT. Get a good ammonia test kit and/or seachem ammonia badge.

+1 on the ammonia badge. I use two in my tank transfer method of QT

Already got the ammonia badge going.... Which is showing "safe" and my API test is showing 0. My nitrite is still .50-1, LFS recommended some
Bottled stuff (Prime and bio boost) so lets see how this works...

The Ammonia Alerts works really well, but don't rely on them for an actual reading. I've found the measurements they show are often 1/10th of the actual amount of ammonia in the water. Best practice is to dose an ammonia detoxifier as soon as you see ANY color change on the alert.

This is correct. Nitrite is not toxic in saltwater like it is in freshwater = even for (most) invertebrates.

You currently have enough bacteria that convert ammonia to nitrite, but the bacteria that convert nitrite to nitrate are not abundant enough. Just keep monitoring ammonia.

Here is a good article on nitrite in a reef:

http://www.reefkeeping.com/issues/2005-06/rhf/

As has been said, nitrite is not as toxic as in fresh. I am quarantining right now (first time for me) and have been watching ammonia real close. Nitrite and Nitrate are higher in my qt tank - seems to be going ok so far.