As I said before I am not using any kno3 as I am not sure what it will do in terms or growing algae... I went to point Roberts on the weekend and picked up some stump remover, I am going to do some reading before mixing it up and putting it on the doser. I also tested my nitrates last week and finally after adding some dry rock that was not cured I have some readings of nitrates but it is in the range of 0-5ppm so I will continue to test and as it falls I will add some of this nitrate.

How long have your sps been in the tank, they look pretty pale... hopefully with kno3 you will see some better colouration in the coming month. Usually sps will look bleached then get brown then colour up. Good luck!

The pictures are not great. They are not as pale as they appear in the photos. The corals have been in my tank for about 1 to 3 months. I have about different 20 sps. I have shown the pictures of the palest ones. All the corals are growing well, they just are paler then I have seen elsewhere.

Even with adding nitrates I still can't get a reading. I will continue to do so. I am also feeding the corals and adding amino acids every day.

Reef tank long time experts like Julian Sprung, Sanjay Joshi, Jason Fox, Elegance Corals, Brad Syphus and other top sps coral collectors are keeping their nitrates at level above 5ppm and some of them up to 50ppm.

There are some horror stories using stump remover, check some forum treads. It works for some but didn't on others.

For me, KNO3 is a better choice to raise your nitrate. It will not only raise your NO3 but will also raise your Potassium (K) level a little bit which is good for coral coloration. You also need to check your K level to make sure it is on the 400 range. It is also easy to dose and calculate the levels, check on the article written by Randy Homes Farley. But again, dose slowly...

Hey man I hear you on that, definately horror stories on a lot of stuff. Equiptment, salt you name it. Anything I do I always try abit and wait awhile to see the coral reactions.

How often are you doing waterchanges and how much?

Changing water about 10 gallons every second week on a 80 gallon system. This was more an effort to reduce phosphates that had gotten really high. Using only RO DI water newer filters. I was only lightly feeding and have a low fish bio load (5 fish). I was using a lot of GFO to help reduce phosphates. I have never registered Nitrates. It was Gregzz4 that told me the 0 nitrates is the problem.

Almost the same issue with me, no no3 and sometimes lots of po4. The colours on my sps are awesome tho so can't complain but the po4 won't go down without no3 they drag each other down....

How's your bioload, how about your feeding? You must be adding enough nitrates in your food that keeps the corals fed and healthy but not enough to stabilize your Phosphates.

Your system is likely using up any nitrates that you add.

I have about 25 fish and feed 3-5x per day dirty food like pei mysis plus coral food so definately a lot of feeding.