PO4 Spike turned Acros brown

Luke Schnabel · Feb 19, 2017

Hey everyone I recently had a spike in PO4. I use a Hannah Checker and I try to keep it around .02-.04 and it shot up to around .08. It took about 2-3 days and all my Acros turned brown.

Salinity: 1.025
pH:8.2
Alk 7
Cal:450
Mg:1400
NO3: 5ppm

I ran some GFO and I now have 0ppm of PO4. Trying to keep it at least detectable. How long does it take an Acro to bounce back from this? I'm getting worried it's been two weeks and they are still not showing any signs of coloring back up.

Diesel · Feb 19, 2017

Wow!
Weird IMO.
I have a Po4 at 0.15 and all is colorful.
You sure you tested right.

Luke Schnabel · Feb 19, 2017

I think so. I use the Hannah low range Checker and that's what it was when I tested. Nothing else changed when it happened. Alk maybe dropped from 7 to 6.8 but that wouldn't make them go brown I wouldn't think. Lights and everything have not been touched.

Luke Schnabel · Feb 19, 2017

What else could make them go brown. I know light can but they were looking great under the light and then in 2-3 days they were brown.
My light is T5, 10a-12p they are getting 110PAR and then 12p-7p they get around 350-400PAR and 7p-10p they are back at 110PAR

mcarroll · Feb 19, 2017

Luke Schnabel said:
Alk maybe dropped

What happened to cause alkalinity to drop? Something out of the ordinary?

Also what happened to cause the PO4 spike?

Luke Schnabel · Feb 20, 2017

I'm pretty sure my Alk went down because my dosing head was not working properly so I replaced it. My Alk never really fluctuates.

I believe my PO4 spiked up because my GFO was exhausted and I didn't catch it in time and I fed my LPS a heavy dose of pellet food during that time. I usually only tested PO4 on the weekends and now I'm doing it Sat-Mon-Wed.

Does anyone know the rebound time of Acros. It's been 2 weeks now.

Waters · Feb 20, 2017

Depends on the species of Acro and the water conditions. Some will start to rebound in weeks....some take months :-(

mcarroll · Feb 20, 2017

I think the dip in alk may have been your primary issue....though the variance in PO4 might not have helped either.

Do you know the peak lux or PAR your tank (or this coral specifically) gets?

Can you post a pic that shows your flow solution? (And what are your tank's dimensions?)

Bdog4u2 · Feb 20, 2017

When I was working a lot last summer my alk dropped from 8.4 to 7.6 and one of my acro's turned light brown in a matter of days and it took months to regain color except on new growth. weird thing just one was affected and it was my cheapest one and new color is different it was purple and now it's Green with a hint of purple.