Triton Testing and Nutrients

[cjpitt80]

About a month ago, I started dosing KNO3 and Phosphat-E to balance nutrient levels. I had no detectable NO3 levels and PO4 levels around 0.25ppm according to the Hanna ULR Phosphate https://hannainst.com/phosphate-ultra-low-range-colorimeter-checkerr-hc-hi774.html
I tried GFO, but because I only had a bag in the sump it wasn't very effective. I subsequently went with the Phosphat-E in an attempt to get the PO4 under 0.1ppm or so. With repeated dosing, I could only get it to about 0.15ppm, though I was able to raise NO3 to around 2ppm. My latest Triton report is listed here https://www.triton-lab.de/en/showroom/aquarium/auswertung-b/icp-oes/74258/ which looks like it is indicating a PO4 of about 0.0070 ppm and high lanthanum. So clearly, to me this means I need to STOP dosing the Phosphat-E now. However, my question is, how should I further monitor phosphate levels? I would assume the Triton is more accurate as the home test has user error...My SPS don't look too hot (and haven't in a while, which is why I started dosing in the beginning) Should I use a PolyFilter to try to reduce the Lanthanum and Lithium?

[bertoni]

The lithium level is consistent with some salt products' makeup, at least historically. I don't think it or the lanthanum levels are problematic, but a PolyFilter seems like a reasonable idea to try, given that your animals seem to be having some problems.

I'd probably scale back the Phospat-E slowly, maybe reducing the amount by ⅓ to ½ and waiting a few days to see how the phosphate level changes, if at all, and continue that pattern until the tank seemed to be within your target range for phosphate. The change in the phosphate level might be the source of problems for your corals, or the rather rapid change might be the cause, rather than the level itself. I'd watch the animals, and give them some time to adapt. How unhealthy do they seem to be?

[cjpitt80]

The lithium level is consistent with some salt products' makeup, at least historically. I don't think it or the lanthanum levels are problematic, but a PolyFilter seems like a reasonable idea to try, given that your animals seem to be having some problems.

I'd probably scale back the Phospat-E slowly, maybe reducing the amount by ⅓ to ½ and waiting a few days to see how the phosphate level changes, if at all, and continue that pattern until the tank seemed to be within your target range for phosphate. The change in the phosphate level might be the source of problems for your corals, or the rather rapid change might be the cause, rather than the level itself. I'd watch the animals, and give them some time to adapt. How unhealthy do they seem to be?

I started my tank with Red Sea black bucket, and switched to blue bucket on advice from Tim at Triton due to high Aluminum. Lithium (and tin) seemed to come with the blue bucket. Never had any Lanthanum, but that is most likely associated with the Phosphat-E

I guess the real problem is unreliable testing. I measured PO4 the same day I sent my ICP sample in and it was 0.14ppm according to Hanna. According to Triton I'm at 0.007ppm. While I wouldn't expect them to agree totally, and I'm more inclined to go with the ICP results, Hanna is reading TWENTY times higher?!?! This obviously is bad. It also leaves me in a little bind if I can't trust the Hanna numbers. I wouldn't have used ANY phosphate reducer if I was closer to the 0.1 number. When I use the the phosphat-E I would see a drop of about 1/3 what is should have been according to the directions. Lowest I could ever detect with Hanna was .08ppm and it rose within 48hrs. At this point, since I'm questioning the Hanna results, and the elevated lanthanum, I think I will STOP with the Phoshphat-E. The only issue is now how to track the PO4 level, as I don't want to drop $50 every week for a PO4 test. I guess I should order PO4 reference solution for the Hanna and see what's going on? Maybe I never had a phosphate issue in the first place and shouldn't have trusted the Hanna

My Euphyllia and duncans look okay (though they don't open quite as fully as they used to). Zoas and Acans seem to be fine. Several plating Montis just seem to lose color, bleach then get covered in algae.

[bertoni]

I am not sure which phosphate result is more likely to be accurate. At low levels like that, the ICP results are fairly suspect, given Triton's methodology. There's a bit of reading on that topic available, if you are interested.

I have had consistent results with the Hach PO-19 and Salifert kits, although they are harder to read than the Hanna. You might have gotten a bad batch of reagents for the Hanna kit. If there's a fish store that would run a phosphate test for you, I might try getting another batch of Hanna reagents, and comparing the results of the store kit and the new reagents. A reference solution is a good idea, too.

All that said, I would look for other possible causes of the coral problems. I do not know much about Montipora. The coral forums might be one source for other ideas.

[cjpitt80]

Yeah clearly something is wrong. I don't know if I have high phoshpate levels or very low levels now.... I got the Hanna specifically because I'm terrible at doing the color tests... That said, I'll have to get another phosphate kit and do some comparisons
I may have never had a high P04 problem in the first place.. ugh
On a bright note after a few weeks of dosing KNO3, I've been able to keep NO3 at 2-3ppm for almost a month now, so SOMEthing is okay, geesh. Mini victories lol

[bertoni]

Well, progress is progress. :)