Nitrate Dosing

[Myka]

My zoas Some of my SPS are a little faded, so 2 weeks ago after some reading I decided to start dosing sodium nitrate (food grade). I dosed 1ppm nitrate daily for 5 days but my nitrates stayed at 0.25ppm the whole time. I'm guessing due to the carbon dosing the nitrate I was dosing was getting consumed rapidly by the bacteria. I kept dosing nitrate at 1ppm for another week, and all of a sudden I noticed some burnt tips, and some of my SPS not looking happy. I immediately tested and my nitrate was now at 4ppm. What I think happened was that at some point, the trace amount of phosphate in my system got stripped and phosphate became limiting.

I have a very similar experience a couple times now. I just resumed NaNo3 dosing 5 weeks ago using Lab Grade Sodium nitrate from The Science Company, dosing 0.75 ppm every night and by morning the NO3 was undetectable using Salifert and Red Sea Pro kits. I didn't notice any difference in my SPS until the 2nd week when suddenly everything stopped growing and I had to stop 2-part dosing completely. 3rd week I'm keeping steady between 0.75-1 ppm NO3. 4th week I have burned tips on Montiporas (Acros look ok, but pale) and still no 2-part dosing so I stopped NaNo3 dosing. This whole time PO4 has been undetectable on Hanna ULR meter. I don't use any GFO or such.

The first time I got burned tips from this same dosing with the same product I had a similar experience where the corals stopped growing and I had to stop 2-part dosing, but I didn't catch it quick enough and had an alkalinity spike. I contributed the burned tips to the alk spike, but now I'm wondering if my burned tips are from the NaNo3 dosing stripping the undetectable PO4 to true zero?? Or maybe there's an impurity in the lab grade stuff that is causing the stress??

 

[furam28]

I have a very similar experience a couple times now. I just resumed NaNo3 dosing 5 weeks ago using Lab Grade Sodium nitrate from The Science Company, dosing 0.75 ppm every night and by morning the NO3 was undetectable using Salifert and Red Sea Pro kits. I didn't notice any difference in my SPS until the 2nd week when suddenly everything stopped growing and I had to stop 2-part dosing completely. 3rd week I'm keeping steady between 0.75-1 ppm NO3. 4th week I have burned tips on Montiporas (Acros look ok, but pale) and still no 2-part dosing so I stopped NaNo3 dosing. This whole time PO4 has been undetectable on Hanna ULR meter. I don't use any GFO or such.

The first time I got burned tips from this same dosing with the same product I had a similar experience where the corals stopped growing and I had to stop 2-part dosing, but I didn't catch it quick enough and had an alkalinity spike. I contributed the burned tips to the alk spike, but now I'm wondering if my burned tips are from the NaNo3 dosing stripping the undetectable PO4 to true zero?? Or maybe there's an impurity in the lab grade stuff that is causing the stress??

Your experience further validates my hypothesis that this is driven by phosphate stripping. Makes biological sense. Both phosphate and nitrate are required for bacterial growth, so when both of them are at undetectable levels and you dose nitrate, eventually phosphate will becoming limiting. I noticed my burnt tips as soon as the nitrate level started creeping up. High alk causing burnt tips is well-known. But there have been a lot of reports of GFO overuse causing burnt tips as well, so I think burnt tip in an ULN setting can be caused by low phosphate as well. In my case there was no increase in alk during the period, so phosphate stripping is the most likely culprit.

Do you do any vodka/noPox/biopellet/zeo?

 

[furam28]

All of the forms of phosphate in seawater equilibrate essentially instantly, so you can dose any form you want (H3PO4, H2PO4-, HPO4--, PO4---).

The only real difference is that adding some will add alkalinity (PO4--- and a small amount from HPO4--) and some will deplete alk (H3PO4, and a small amount from H2PO4-).

I think dosing it is a fine plan.

Thanks Randy. I have started dosing sodium phosphate (dibasic) and I will dose it at 0.02ppm daily and see if that slows down the burnt tip. I should start taking daily pics of the frags in question so I can document the progression. Last 3 days my Alk has been stable at 140ppm (7.84 dKh) as measured by Hanna.

 

[Randy Holmes-Farley]

Sounds good.

Good luck!

 

[Myka]

I noticed my burnt tips as soon as the nitrate level started creeping up.

Me too.

Do you do any vodka/noPox/biopellet/zeo?

Nope. Tank has been low nutrient from day one (set up July 1, 2015 ) because of low fish load and oversized skimmer.

I just increased my fish load by 20% a few days ago as well.

 

[grim1reaper72]

Thanks Randy for taking the time to answer my question.

 

[Randy Holmes-Farley]

Thanks Randy for taking the time to answer my question.

You're welcome.

Happy Reefing.

 

[Randy Holmes-Farley]

Me too.

.

Curious that folks who are trying to avoid a ULNS situation by dosing nitrate may inadvertently cause one (via low phosphate).

 

[Myka]

Curious that folks who are trying to avoid a ULNS situation by dosing nitrate may inadvertently cause one (via low phosphate).

It is, isn't it? *grumble*

 

[Myka]

I went on the search for liquid Nitrates. Brightwell sells it although it wasn't readily available, I was able to locate a vendor with the help of Brightwell.

What is the Brightwell product called? I know they have one for phosphate dosing too. I can't seem to find them on their website. Unless maybe people are referring to the Brightwell products designed for freshwater planted tanks??

 

[Lazys Coral House]

What is the Brightwell product called? I know they have one for phosphate dosing too. I can't seem to find them on their website. Unless maybe people are referring to the Brightwell products designed for freshwater planted tanks??

Here is the brightwell product I used. I have been able to stop using it with heavy feedings. The po4 and nitrate have been able to be maintained where I want it. Nitrate around 5-10 and po4 .02-.05
It took quite a lot of dosing and feeding to get them to stay at those levels but now it is maintained and fish and corals are doing well.
http://www.bulkreefsupply.com/neoni...rkcQ7MmCrN70hDPQlKW_VC7VFzZ28tG59khoCn1Hw_wcB

 

[furam28]

I dosed 0.2ppm phosphate yesterday. An hour later I tested with Salifert and it was around 0.125 - 0.25. Today morning, 10 hours later phosphate is undetectable. That's a very high phosphate demand. No wonder my SPS were suffering. Nitrate is at 4ppm. I reduced my NoPox dosing further from 1.6 to 0.8mL per day. Dosed another 0.2ppm phosphate. Will check again tonight.

 

[furam28]

What is the Brightwell product called? I know they have one for phosphate dosing too. I can't seem to find them on their website. Unless maybe people are referring to the Brightwell products designed for freshwater planted tanks??

The one lazylivin posted is the nitrate. Here is the phosphate supplement: http://www.bulkreefsupply.com/neophos-balanced-phosphorus-supplement-brightwell-aquatics.html

 

[Kungpaoshizi]

Reef Energy is the best product I've found to introduce nitrates. It's also a pretty darn good food for everything... (I dose it 24x7 and the coloration/growth is pretty nice; using a cheap usb mini fridge with 100ml bottles, refill them once a week)

 

[Randy Holmes-Farley]

I dosed 0.2ppm phosphate yesterday. An hour later I tested with Salifert and it was around 0.125 - 0.25. Today morning, 10 hours later phosphate is undetectable. That's a very high phosphate demand. No wonder my SPS were suffering. Nitrate is at 4ppm. I reduced my NoPox dosing further from 1.6 to 0.8mL per day. Dosed another 0.2ppm phosphate. Will check again tonight.

Some of that dose likely bound to rock and sand.

 

[Redbarnreefer]

Great thread, curious @furam28 has any updates?

 

[JPK]

sorry if I missed it, but how do you determine what ppm concentration/dose of sodium nitrate you are using for your tank size?

For example, how would you mix powder sodium nitrate and/or trisodium phosphate with ro/di water to achieve a .75 ppm dose to a 120 gallon (actual water volume) system? I have a scale accurate to 0.1 grams. I ideally would like to auto dose this/these daily once a balance was achieved.

And I would assume this would be the same for powder trisodium phosphate?

http://www.amazon.com/Sodium-Nitrat...qid=1460912115&sr=8-2&keywords=sodium+nitrate

My SPS system has undetectable levels of both nitrates and phosphates (good fish stock and a lot of feeding).

Thank you

 

[Randy Holmes-Farley]

You need to know the exact form for phosphate dosing calculations. Trisodium phosphate s only one of several possibilities. So before I go through the math, let's be sure which one you want.

Here's a recipe for potassium nitrate, and it can be adjusted easily for sodium nitrate if you choose to use that:

Dissolve 10 grams potassium nitrate in 1 liter of fresh water. That 10 grams contains 6.14 grams of nitrate, so that solution is 6,140 ppm nitrate.

If you add 1 ml of the solution per 2 gallons of tank water volume, that will boost nitrate by 0.8 ppm nitrate

 

[Slm222]

Which would be better randy? Sodium nitrate or potassium nitrate?

 

[Randy Holmes-Farley]

Which would be better randy? Sodium nitrate or potassium nitrate?

It probably doesn't matter, but if you are not occasionally monitoring potassium, I'd use sodium.

Here's the above recipe adjusted for sodium nitrate:

Dissolve 8.4 grams of sodium nitrate in 1 liter of fresh water. That 8.4 grams contains 6.14 grams of nitrate, so that solution is 6,140 ppm nitrate.

If you add 1 ml of the solution per 2 gallons of tank water volume, that will boost nitrate by 0.8 ppm nitrate