(Dry) food grade potassium nitrate amount?

[Scott.h]

Rather than burn out a couple of test kits I figured I'd ask. I have about 100 gallons total water volume and undetectable nitrates. Wondering how much dry I should add to the tank per week to get me in the ballpark of being consistently detectable. Looking to add it to my 5 gallons a week auto top off water once I'm close. Quite a bit a rock work, 20 or so frags. 1/8 tsp too much? Mixing with rodi of course..

 

[Ocelaris]

Here's a good thread and recipe, I make a half liter or so and dose 20ml every other day or three on my 130 total water volume tank.

https://www.reef2reef.com/threads/r...emover-potassium-nitrate.283886/#post-3455084

It usually takes a few days to get up to about 5ppm nitrates and hold it there. Initially you may have to add a bit more for the first few days. Once you get a stable amount you will see results in the few days.

 

[Scott.h]

Here's a good thread and recipe, I make a half liter or so and dose 20ml every other day or three on my 130 total water volume tank.

https://www.reef2reef.com/threads/r...emover-potassium-nitrate.283886/#post-3455084

It usually takes a few days to get up to about 5ppm nitrates and hold it there. Initially you may have to add a bit more for the first few days. Once you get a stable amount you will see results in the few days.

I've found a lot on spectracide, but I chose to buy food grade dry because I simply don't know the impurities in spectracide. (I realize a lot of people use that). So I don't really know how deluded spectracide is compared to the dry granules. I put 1/8 tsp in a 17 oz bottle of rodi. Just kind of been splashing some in my sump every few hours. I have no idea if it will suck up that whole 17 oz bottle and still be undetectable or maybe it will be 10. No clue. I'm aiming for slightly pink through the side of the salifert test tube.

 

[ocboat]

Spectracide is not diluted, its a dry granule just like you purchased.

 

[Ocelaris]

Right, potassium nitrate = potassium nitrate = potassium nitrate. Unless it was anhydrous; but I am pretty sure you didn't because it's more expensive and probably not food grade. So the same formula would apply.

Here's a good dosing calculator:

https://rotalabutterfly.com/nutrient-calculator.php

But realistically, get close with your mix and then test daily.

 

[Randy Holmes-Farley]

Potassium nitrate does not typically come as hydrates (the way magnesium salts usually do), so the calculators for potassium nitrate solid are typically fine.

 

[Scott.h]

My nitrate must really be depleted. I keep feeding more.. fish food, then coral food. I added 1/8tps last night of nitrate spread out. Tested this morning. I can't see any pink even from the side view (which is 10x). I'm trying not to get carried away so I don't get a spike but I have two corals specifically that have been effected as the tank matures more. Considering removing the little bit of macro in the sump also, but trying to weigh the pluses and minuses of that also.

That calculator is really cool.. thanks for that. Hopefully I'm reading it correctly