Nitrates bottoming out and SPS

[Fishboy9227]

Important details:

• Tank is 200g
• Alk is 8.5-8.6 -controlled by apex and trident
• Calcium- 450
• Mag- 1410
• Salinity- 1.026
• Tank is 9 months old, seeded with established liverock
• Lighting is 2 hydra 62s running about 60% and 4 T5s. Par values were about 250-350 on sps

I placed some chaeto in my newly connected fug and it took off growing, to the point that I couldn’t get nitrates to test on a Salifert test kit. I noticed that the acros in the tank began having less and less polyp extension. A few are beginning to show random white spots (I say random as it’s not the tips or the base).

Can nitrates bottoming out cause this? Is it common for acros to show signs of stress a week or so after the nitrates bottoming out?

I’ve seen started dosing nitrates to 2.5-5ppm. Phosphates are now showing zero with a salifert test kit. I’m not for sure where they’ve been as I realized I had the wrong reagent for my test kit.

 

[Fishboy9227]

 

[Fishboy9227]

 

[Fishboy9227]

Per research, it appears the current state of some of my acros would suggest something greater than nitrates zeroing out (I suspect a false reading). However, alk has remained pretty stable. All other corals are looking pretty good. Torches are extending and coloring up more than ever after dosing nitrates.

 

[lemonade]

It definitely can be from low nutrients, but might not be the direct cause. Just weakens the corals to a point where they’re very sensitive. I’d start by pulling the cheato from the tank. If you have any algae, or dinos growing in the tank they will be eating up nutrients as you dose them. A better route would be feeding the fish more making sure the food that goes in is eaten and not getting sucked into the overflow or beneath the rock work.

 

[jmichaelh7]

Consider if you need a refugium if your nitrates are bottoming out.

Consider getting a reputable test kit.

i assume you have an algae outbreak such as dinos? I had almost the same issue and once i dosed nitrates the colors popped back and corals were happy

 

[Fishboy9227]

I’m using salifert and Hanna checkers for phosphate (though I had the wrong reagent ).

I do have some kind of nuisance algae/cyano that I have gotten to go away by running gfo.

i turned the light off to the ref last week but will take it out tonight. Thanks for the response.

 

[Fishboy9227]

Thanks.
I have an auto feeder running twice a day with a mix of mysis pellets and NLS. I’ll up that. And keep more nori available for the tangs. probably need more fish (2 tangs, 2 clowns, coral beauty, and hawkfish). I’ve been confused about the algae/cyano with a relatively light bioload.

Thanks for the response.

 

[resortez]

There’s definitely more room for fish in a 200 gallon. The OP has no mention of temps or PO4, what are those reading?The cheto is exporting a large load of NO3 but hardly any are being imported back in. Sounds like the tank is starving for nutrients & would help in boosting the bio load by adding more fish, along with feeding a bit heavier. It’s all a balancing act, there has to be an equal exchange. Good luck

 

[C. Eymann]

Are you occasionally checking your alk with a titration kit like a Salifert to confirm your Trident is reading correctly?

 

[Fishboy9227]

There’s definitely more room for fish in a 200 gallon. The OP has no mention of temps or PO4, what are those reading?The cheto is exporting a large load of NO3 but hardly any are being imported back in. Sounds like the tank is starving for nutrients & would help in boosting the bio load by adding more fish, along with feeding a bit heavier. It’s all a balancing act, there has to be an equal exchange. Good luck

Temp is 78-79.
P04 is currently testing zero with salifert. My reagent for my ULR Hanna check will be here tomorrow.

 

[Fishboy9227]

Are you occasionally checking your alk with a titration kit like a Salifert to confirm your Trident is reading correctly?

I have. It reads a little higher, usually 8.8 or so.

I recalibrate the trident each time I change out reagent A.

 

[C. Eymann]

I have. It reads a little higher, usually 8.8 or so.

I recalibrate the trident each time I change out reagent A.

Tridents are great tools, but they aren't exactly the most accurate, I would trust a correctly performed titration test like a Salifert than I would a Trident, esp if you get the same result twice.

When using LED lighting especially, running an alk of 8.8-9.0 dkh with N/P occasionally bottoming out can cause big problems with acropora.

 

[Fishboy9227]

Tridents are great tools, but they aren't exactly the most accurate, I would trust a correctly performed titration test like a Salifert than I would a Trident, esp if you get the same result twice.

When using LED lighting especially, running an alk of 8.8-9.0 dkh with N/P occasionally bottoming out can cause big problems with acropora.

Thank you for confirming this.

ill check more with my salifert kit.

 

[AutumnReefs]

Get more fish or feed more. Amino acid supplements daily can help. Dial back the refugium light if needed.

 

[ctopherl]

I’m using salifert and Hanna checkers for phosphate (though I had the wrong reagent ).

I do have some kind of nuisance algae/cyano that I have gotten to go away by running gfo.

i turned the light off to the ref last week but will take it out tonight. Thanks for the response.

The refugium is just another filter you can dial in. I'm not sure how you were running it, but for example if you were running it 8 hours/day, try running it 8 hours EVERY OTHER day. See if nitrates creep back up. You can alter how long you have the light on to alter how rapidly nitrates and phosphates are depleted.

Not sure about phosphates though since you're also running gfo, that will make it more complicated.

 

[Frank RiZZo]

Take Gfo and throw it in the trash , shut down fuge until you see 5-10no3 and 0.03-0.05 po4

 

[Fishboy9227]

Thanks everyone for the replies and help. Appreciate it. I have turned off the GFO and refugium. As recommended, I will allow nitrates to sit at 5-10pm and phosphate around .03. I'll continue to double check alk with my salifert test kit.

 

[Fishboy9227]

Tested the phosphate with the Hanna ULR checker when I got home and it’s showing .06ppm. Little high I suppose. Should I do anything or just focus on nitrates and monitor phosphate. I do have some nuisance algae/cyano that I’d like to rid.

 

[blasterman]

Take Gfo and throw it in the trash , shut down fuge until you see 5-10no3 and 0.03-0.05 po4

This ^^^^^^^^^^^^^^^^^^^^^^^^^^

If it's an established tank phosphate at .06 is fine - keeping it stable it most important. Montipora and birdsnests go bonkers with phosphate .05 - .1

.03 gives you wiggle room for more feeding.

If you have zero or hyper low nitrate remember to raise it *slow*. Acropora in particular don't take kindly to rapid nutrient increase.