Nitrate spike during established vinegar dosing regimen

adubson · 08/09/2015, 03:33 PM

I began dosing vinegar + weekly MB7 in my 75 gallon mixed reef in January, and until June the results were great. Nitrates and phosphates decreased relatively quickly and stayed there for that entire time. Now, for the past two months I have been battling some major instability issues, and I cannot pinpoint the issue, if there is even just one.

The initial breakdown was with an Alk dropoff. Not too drastic, but dropped from the usual 8-9 to 6 and was seemingly locked there after many attempts to dose alk additives to bring it up. Continuous high dosing, and the addition of 2 part daily dosing to the previous Kalk setup have resulted in stable Ca/Alk finally. However, somewhere along this path I began getting large spikes in nutrients, especially nitrates. Nitrate levels were seen around 10-20, and phosphate levels were elevated (only had an API test kit at the time, but went through some major GHA outbreaks). So, I upped the vinegar dose, but nothing has happened.

Now, I have been attempting to let my tank sit for a couple weeks without water changes (normally do 15-20% water changes every other week) to hopefully settle out, but now my nitrates are up to 80 ppm on the API test kit. All other major parameters (Ca, Alk, Mag, pH, temp, and salinity) are in acceptable ranges, and phosphate appears to be less than 0.025 on the NYOS phosphate kit (color discrimination between 0 and 0.025 is difficult). Any ideas on what has happened to my carbon/probiotic dosing regimen? Could I have thrown the bacterial populations out of whack?

Could I possibly need to change carbon sources, or change the bacteria that's being dosed?

bertoni · 08/09/2015, 04:40 PM

The decrease in alkalinity might be due to more growth, although there are a lot of possibilities. People run into problems with salt batches or settling, and measurement issues, too. How is the skimmer doing? Has it been checked recently? I'd test for nitrite, as it can confuse nitrate test kits, and I'd get a second opinion on the nitrate kit, as well. If the nutrient level increase is real, I suspect you'll need to cut back on feeding, but I'm suspicious right now.

zachfishman · 08/09/2015, 05:22 PM

Curious,. How does your phosphate now compare to when you were successfully removing P and N via carbon dosing? If you are now PO4 limited as your tests might suggest, your carbon dosing won't be able to remove NO3 as effectively as before (bacteria need C, N, and P to grow).

adubson · 08/09/2015, 07:56 PM

Quote:

Originally Posted by zachfishman

Curious,. How does your phosphate now compare to when you were successfully removing P and N via carbon dosing? If you are now PO4 limited as your tests might suggest, your carbon dosing won't be able to remove NO3 as effectively as before (bacteria need C, N, and P to grow).

That's what I've been thinking, in terms of the right balance of nutrients. Unfortunately I only just upgraded my phosphate test kit during this debacle. When things were going well, I only had an API phosphate test kit, so all I know is that it was undetectable by that kit.

Another thought, if it is a balance thing, would increasing the phosphate (via something like seachem phosphorus) in order to re-establish the correct ratio possibly work?

adubson · 08/09/2015, 07:57 PM

Quote:

Originally Posted by bertoni

The decrease in alkalinity might be due to more growth, although there are a lot of possibilities. People run into problems with salt batches or settling, and measurement issues, too. How is the skimmer doing? Has it been checked recently? I'd test for nitrite, as it can confuse nitrate test kits, and I'd get a second opinion on the nitrate kit, as well. If the nutrient level increase is real, I suspect you'll need to cut back on feeding, but I'm suspicious right now.

Skimmer seems to be doing fine. I have an eshopps s120 cone skimmer. I could probably increase the skimming a bit. I change the skimmer cup at least once a week.

dartier · 08/09/2015, 09:27 PM

I experienced something similar to this. I have been meaning to post a thread about it, but never got around to it.

I was dosing the DIY NOPOX for several months with good results. Then I seemed to hit a wall. My Nitrates and Phosphates kept rising. I tested for, or dosed all the usual suspects that are needed for carbon dosing (potassium, iron, iodine, etc.). Nothing was out of whack that I could find/test for. After bumping my carbon dose a bit higher to see if I just needed a bit more to get things headed down, my purple fire fish became covered in some weird white stands all over his body. I was sure I was going to lose the fish. I prepared to quarantine him, but he was way too fast to catch. I figured it was not a coincidence and stopped carbon dosing. The strands started to relent the day after I stopped carbon dosing (they had been increasing for a week), and were fully gone in 3 days.

Out of desperation, I switched to All In One pellets, which I had used before, but stopped due to being messy. This took my Phosphate down, but did not touch the nitrate. I figured the GFO in the pellets was taking the PO4 down, but the pellets were not touching the nitrate. I even started dosing Seachem Phosphorus to keep the PO4 above 0.00 ppm.

During this time my frags and coral remained with good colour and growing, even though my nitrate is 50 ppm, which I thought was quite odd. However the polyp extension left a lot to be desired.

At this point I started working on a sulfur denitrator to help with the nitrate. Since I was testing it offline, I needed some test water, so I did a big water change and used the old high nitrate water.

Then something unexpected happened. All my corals showed much improved polyp extension, but most of them darkened with some even browning out.

What I think was happening is that my daily water change, which I always assumed was about 1%, was probably smaller than I thought. My belief is that something was being depleted and it eventually made the carbon dosing ineffective, although the corals looked really good. I think the manual large water change helped to resolve this somewhat, and now the higher nutrients are having an impact on the zooxanthellate, and they are darkening as a result. My PO4 is sitting at 0.03 ppm and I have lowered the dosing for it.

You may want to try a decent sized water change if you have not been changing a lot while carbon dosing, and see if it helps.

Dennis

adubson · 08/10/2015, 01:45 PM

I was routinely doing 15-20% water changes every other week. 2 weeks ago I did back to back 33% water changes to hopefully cut down the nitrates, with the plan to let the take sit for a bit after that final water change to stabilize.

Nitrates measured at 10 ppm after the last water change. Currently, they're at 80. I was also dealing with some cloudy water at the time so I tried a bag of chemipure elite. This cleaned up the water very rapidly and most of the remaining nuisance algae. Don't know if it had some effect on the nutrient balance though...

08/09/2015, 03:33 PM	#1
adubson Registered Member Join Date: Oct 2014 Location: Chicago Posts: 22	Nitrate spike during established vinegar dosing regimen I began dosing vinegar + weekly MB7 in my 75 gallon mixed reef in January, and until June the results were great. Nitrates and phosphates decreased relatively quickly and stayed there for that entire time. Now, for the past two months I have been battling some major instability issues, and I cannot pinpoint the issue, if there is even just one. The initial breakdown was with an Alk dropoff. Not too drastic, but dropped from the usual 8-9 to 6 and was seemingly locked there after many attempts to dose alk additives to bring it up. Continuous high dosing, and the addition of 2 part daily dosing to the previous Kalk setup have resulted in stable Ca/Alk finally. However, somewhere along this path I began getting large spikes in nutrients, especially nitrates. Nitrate levels were seen around 10-20, and phosphate levels were elevated (only had an API test kit at the time, but went through some major GHA outbreaks). So, I upped the vinegar dose, but nothing has happened. Now, I have been attempting to let my tank sit for a couple weeks without water changes (normally do 15-20% water changes every other week) to hopefully settle out, but now my nitrates are up to 80 ppm on the API test kit. All other major parameters (Ca, Alk, Mag, pH, temp, and salinity) are in acceptable ranges, and phosphate appears to be less than 0.025 on the NYOS phosphate kit (color discrimination between 0 and 0.025 is difficult). Any ideas on what has happened to my carbon/probiotic dosing regimen? Could I have thrown the bacterial populations out of whack? Could I possibly need to change carbon sources, or change the bacteria that's being dosed?

08/09/2015, 04:40 PM	#2
bertoni RC Mod Join Date: Mar 2002 Location: Mountain View, CA, USA Posts: 88,616	The decrease in alkalinity might be due to more growth, although there are a lot of possibilities. People run into problems with salt batches or settling, and measurement issues, too. How is the skimmer doing? Has it been checked recently? I'd test for nitrite, as it can confuse nitrate test kits, and I'd get a second opinion on the nitrate kit, as well. If the nutrient level increase is real, I suspect you'll need to cut back on feeding, but I'm suspicious right now. __________________ Jonathan Bertoni

08/09/2015, 05:22 PM	#3
zachfishman Registered Member Join Date: Sep 2003 Location: St Petersburg, FL Posts: 3,577	Curious,. How does your phosphate now compare to when you were successfully removing P and N via carbon dosing? If you are now PO4 limited as your tests might suggest, your carbon dosing won't be able to remove NO3 as effectively as before (bacteria need C, N, and P to grow). __________________ Patience is a reefer's best tool. Secret Xenia lover. M.S. Marine Biology Staff - Marine Discovery Center, St. Petersburg FL Tampa Bay Reef Club BOD 2018 Current Tank Info: 34g modded Solana

08/09/2015, 09:27 PM	#6
dartier Registered Member Join Date: Aug 2012 Location: Brampton, ON, Canada Posts: 958	I experienced something similar to this. I have been meaning to post a thread about it, but never got around to it. I was dosing the DIY NOPOX for several months with good results. Then I seemed to hit a wall. My Nitrates and Phosphates kept rising. I tested for, or dosed all the usual suspects that are needed for carbon dosing (potassium, iron, iodine, etc.). Nothing was out of whack that I could find/test for. After bumping my carbon dose a bit higher to see if I just needed a bit more to get things headed down, my purple fire fish became covered in some weird white stands all over his body. I was sure I was going to lose the fish. I prepared to quarantine him, but he was way too fast to catch. I figured it was not a coincidence and stopped carbon dosing. The strands started to relent the day after I stopped carbon dosing (they had been increasing for a week), and were fully gone in 3 days. Out of desperation, I switched to All In One pellets, which I had used before, but stopped due to being messy. This took my Phosphate down, but did not touch the nitrate. I figured the GFO in the pellets was taking the PO4 down, but the pellets were not touching the nitrate. I even started dosing Seachem Phosphorus to keep the PO4 above 0.00 ppm. During this time my frags and coral remained with good colour and growing, even though my nitrate is 50 ppm, which I thought was quite odd. However the polyp extension left a lot to be desired. At this point I started working on a sulfur denitrator to help with the nitrate. Since I was testing it offline, I needed some test water, so I did a big water change and used the old high nitrate water. Then something unexpected happened. All my corals showed much improved polyp extension, but most of them darkened with some even browning out. What I think was happening is that my daily water change, which I always assumed was about 1%, was probably smaller than I thought. My belief is that something was being depleted and it eventually made the carbon dosing ineffective, although the corals looked really good. I think the manual large water change helped to resolve this somewhat, and now the higher nutrients are having an impact on the zooxanthellate, and they are darkening as a result. My PO4 is sitting at 0.03 ppm and I have lowered the dosing for it. You may want to try a decent sized water change if you have not been changing a lot while carbon dosing, and see if it helps. Dennis __________________ 560G Miracles tank in process making a DIY DyMiCo style filter (for 560G) Current Tank Info: 560G Miracles tank in progress, 80Frag Temporary

08/10/2015, 01:45 PM	#7
adubson Registered Member Join Date: Oct 2014 Location: Chicago Posts: 22	I was routinely doing 15-20% water changes every other week. 2 weeks ago I did back to back 33% water changes to hopefully cut down the nitrates, with the plan to let the take sit for a bit after that final water change to stabilize. Nitrates measured at 10 ppm after the last water change. Currently, they're at 80. I was also dealing with some cloudy water at the time so I tried a bag of chemipure elite. This cleaned up the water very rapidly and most of the remaining nuisance algae. Don't know if it had some effect on the nutrient balance though...