I agree but a zero reading doesn't say much especially on low grade kits. I know corals like bacteria use more nitrogen than phosphorus whether or not there's a perfect number I font think there is but they do need some as their basic needs.

I wouldn't be adding nitrates unless I am carbon dosing and even then it would have to be severe.

Not sure overfeeding will do much besides add more phosphates, upping the bioload will help but if carbon dosing then it's only temp until the denitrifying bacteria catch up.

A zero is kind of a neutral point , are we below zero or are we way below zero , I agree shooting for zero on hobbyists kits is ideal as there is sure to be n and p being used in conjunction to what's being read.

If colors are the issue or even growth then I too would look at other things mainly lighting , totm on RC right now only measures three parameters alk,salinity and phos and his phos is 0.21 so I don't think having it really low is a must as he obviously has no issues with growth colonies are huge and colors are amazing, 400w radiums baby lol

Greg what would make You think your nitrate deprived or do you think that?

Pee in the sump!:lol:

But seriously, I'm nitrate limited too. I run biopellets (carbon source), I have high phosphates, and undetectable nitrates. From my reading, I take it I need to up my nitrates in order to lower my phosphates.

Sorry I don't have a solution, but I'll tag along....

Like all forms of carbon dosing Your pellets remove more nitrates than phosphates so running either more amounts of gfo at a time or less amounts more often would be better than raising your nitrates. You can also remove some pellets if you think it's really low. I believe it's about 16:1 for the ratio . Again over feed will add more po4 than nitrates.

I'm currently removing the biopellets and replacing with vinegar more control and all around healthier than ethanol or sugars

There's more to Colors and growth than n and p , lighting and flow are also crucial;)

There's a thread on RC called dosing nitrates in the chemistry forum it's a good read and prob the one brads talking about I'd link it but I'm out and a about town atm but some good info on why one would dose them.and what to dose. Again adding nitrates directly is a bit touchy of a subject and seems to be more beneficial ways of doing it.

I dont think adding NO3 will solve any problems with SPS. JMO.

Yeah, sure can't figure why you would want to raise your nitrates... I spent about a year getting mine down from a high of 100 ppm to zero with bio pellets. They have been zero for about 2 years now. But just a couple of weeks ago, I removed my bio pellet reactor since it wasn't consuming many bio pellets anymore. However, just noticed now that my nitrates are no longer zero. They just barely register some colour now, so still less than 5, but not zero anymore. I was surprised actually, and will definitely keep a close watch with my testing. If they continue to rise, will install the bio pellet reactor again.

My phosphates are running around .04 - .08 lately, too high IMO. I had them down to zero last year, too, and had my best SPS growth and colour then,.. and no algae. I think P04 actually has the biggest effect on SPS growth. Some SPS (birdsnest, valida, montis, etc) of course grow just fine with higher nutrients. But my deep water smoothies definitely like the low P04.

I'm with you I don't think the impact higher nitrates will have will be huge or beneficial to Sps longterm.

Agreed.

SO what is the problem with the SPS. You could probably get some good advice here.

Definitely 5ppm NO3 is not needed. I dont think it would hurt but I have had great SPS growth and colour with unregistered NO3 and PO4.

Personally I think that when people see a positive reaction to increasing NO3 or PO4 it's actually a postivie reaction to something higher up on the nutrient/food chain. Ie. feeding more.

My philosophy is high import (larger bioload, larger amount of quality food) and high export (quality filtration). Bascially allowing there to be a constant influx of food yet with the filtration ablity to keep the broken down by products (disolved NO3 and PO4) to a minimum.