Can sodium nitrate be dangerous to corals?

Docdiggy · May 8, 2018

I guessing no, but ever since I started dosing I've been losing all my sps. I did end up overdosing initially, but it came down as did my phos. All algae I had in the sand and cyano went away too.

Randy Holmes-Farley · May 8, 2018

How much did you overdose?

Docdiggy · May 8, 2018

Sigh......i was at 0. My red sea kit only goes up to 4. If I had to guess 10-12ppm. I got lazy with the 2ml syringe and poured some in. Phos was at .11 and dropped to a low of .03. At this point the levels are nitrate 1ppm and phos .04. I overdosed about 2 months ago and things are still dying. Polyps disappear and then eventually they bleach and die.

Docdiggy · May 9, 2018

It's my fault on the OD, but things have been quite stable for a while now. My lps took really well and have looked very full and colorful since dosing.

hyprc · May 9, 2018

I've been dosing sodium nitrate for about 3 weeks now and just barely saw a non-zero test reading (salifert) of 2.5 - corals seem to like it =\ sorry to hear about the OD. I saw a similar diminishing of algae and cyano although now I'm starting to see some green hair pop up here and there in very small patches. May back off my daily no3 dose

Randy Holmes-Farley · May 9, 2018

I’d be surprised if that dosing was an issue. Lots of people have raised nitrate similarly without issue, and I’m not sure why it would do anything more than brown up corals due to zooxanthellae increases.

Maybe phosphate got too low, maybe some toxic organism grew, or maybe it was coincidence.

Docdiggy · May 9, 2018

I've been dosing 2-4ml a day to maintain a level and it seems like I'm just poisoning things. I just noticed another sps bleaching today that has been fine during the original dose. I don't really know where else to look for the cause.

Starblenny · May 9, 2018

Docdiggy said:
I've been dosing 2-4ml a day to maintain a level and it seems like I'm just poisoning things. I just noticed another sps bleaching today that has been fine during the original dose. I don't really know where else to look for the cause.

How's your alk?

Docdiggy · May 9, 2018

8.6. I brought it down from 9.6 over a week and a half. Things were not good even before that. 90% of my lps are fine. Most sps are fading or bleaching. Deresa clam is fine. I use a Hanna checker for alk. I really want to compare it to another good test. I have 2 bottles of regant and they test very close to each other.

jda · May 9, 2018

While no single number in that range seems dangerous, bouncing around can be hard on SPS. Having an undetectable amount of nitrate is no issue. If you suspect it, why don't you stop dosing? I would phase it out over a week.

In most tanks with sand and real, functioning live rock, you are only really driving the bacterial population higher, to a new-high "equilibrium" and then the corals fight for the scraps, just like they did at lower levels.

Docdiggy · May 9, 2018

If the level is detectable now, then there shouldn't be much of a fight?

Docdiggy · May 9, 2018

I've been racking my brain trying to think of anything that could cause this. Back in Dec I had a hose fall out of my remote sump from an algae reactor. It drained my sump entirely over night leaving all rocks exposed. I'm sure that probably caused a mini cycle, but would that continue to kill even 5 months down the road?

jda · May 9, 2018

The easiest thing is usually the thing. Walk back your changes from most recent on backwards. If dosing NaNO3 was the last thing, then it should be the first thing removed.

Docdiggy · May 9, 2018

The reason I dosed nitrate was because it was at 0 while phos was getting pretty high. Feeding more would only make the phos level higher. Purple sps seemed brown and I read it wasn't good to be 0. My sand had quite a bit of algae/cyano. Dosing nitrate completely fixed it. Randy could be right about a coincidence, but I'm thinking of changes I did prior to dosing. Larger skimmer and sump drain. Both were 5+ months ago though.

Docdiggy · May 10, 2018

Update....A local guy came over to take some coral before they die. He brought a bucket of water. He uses RODI to calibrate his refractometer and I have been using a solution from bulk reef. I found his water reading .021 and my tank reading .025 when using the solution to calibrate. When calibrating with RODI his water said .025 and my tank was .030. I'm blown away that this could be my problem after all this time.

Idoc · May 10, 2018

I only have LPS in a quarantine tank right now. They were all dying from no nutrients...and chrysophytes were taking over. Cleaned out the chrysophytes, started dosing sodium nitrate to around 2ppm.... and after about a month, they are coming back beautifully so far. The palys have gotten their vibrant colors back as well.

Docdiggy · May 10, 2018

My lps looked better after dosing also, but the point of my thread was everything dying. Now I'm wondering if trusting the calibration fluid has caused my salinity to be to high. Not the nitrate dosing.

hyprc · May 10, 2018

Hopefully the high salinity was the culprit and you can bring things back in line slowly. Hope some corals come back!

Nice goat

Docdiggy · May 11, 2018

Thanks!!

What's an acceptable amount of time to drop salinity?

hyprc · May 12, 2018

Docdiggy said:
Thanks!!

What's an acceptable amount of time to drop salinity?

If it were me (and I'm no expert), I'd either skim heavy and/or (more likely) pull a few cups of water out of the tank throughout the day and let the ATO replace it gradually lowering salinity. I'd shoot for a time frame of 2 or 3 weeks to get to 1.026ish