Favia Bleaching. Perhaps, High Alk is the issue, not sure!!!

[NShirke]

My favia was doing great, but I can see it started bleaching today. I think high alkalinity could be the problem, but not sure if thats the case. I wanted to check get suggestions from the community.

Here are my water parameter -

Salifert test kit

• Calcium - 420
• Mg - I think between 1180 - 1200
• Alk - 13.5 (Increased from 10 to 13 in a week)
• Phosphate = 1 (this has remained constant since the introduction of the coral, a few weeks back).

Ph- 8.0(Using API test kit)
Temperature - 79
Salinity - 34 (checked by hydrometer)

I dose B-ionic 2 part - 10ml Cal and Alk, 6ml Mg every day. I've a 40g breeder running with little over a year of tank maturity. I change water every 2-3 week using RO/DI water with Instant Ocean salt .

 

[Reeffragger]

Mag seems pretty low for alk that high. They run two in two. So id try to lower that alkalinity. Or raise the magnesium to 1350.

 

[Jonify]

Agree with @Reeffragger ... Mag usually tracks alkalinity and calcium ... I wouldn't dose, because that might make it worse, but a 20-30% water change, or a couple of 10% water changes should get it back in line. You dosing anything on this tank? Kalkwassser, etc.?

 

[SR Reefing]

Something not right with your number. When Alk 13 your Cal should be low like 380 or less. Especially with your low Mag.

Also PH at 13 Alk might run around 8.5 or higher during the day.

Maybe you should double check your test kit result.

 

[NShirke]

okay, let me try that. Planning to perform additional water change tomorrow. I changed it last week, but let's see doing both, water change, and increasing Mg will resolve it.

 

[Jonify]

Just re-read your numbers. I think your dosing may be off ... maybe a few water changes, then monitor your levels manually, then adjust your dosing. As tanks mature, uptake changes ... just requires constant adjustment as it ages.

 

[NShirke]

Something not right with your number. When Alk 13 your Cal should be low like 380 or less. Especially with your low Mag.

Also PH at 13 Alk might run around 8.5 or higher during the day.

Maybe you should double check your test kit result.

I checked all parameter including Ph around 9pm Est. So, it may be higher during the day as Ph falls at night time.

 

[NShirke]

Agree with @Reeffragger ... Mag usually tracks alkalinity and calcium ... I wouldn't dose, because that might make it worse, but a 20-30% water change, or a couple of 10% water changes should get it back in line. You dosing anything on this tank? Kalkwassser, etc.?

Nope, no Kalwasser. I'm dosing B-ionic for Cal/Alk and mag.

 

[NShirke]

Thanks for the input @Jonify, @SR Reefing, and @Reeffragger.. I'm going to perform 20% water change tomorrow. Gladly, I have water ready. I hope the coral bounces back. Just so you all know, I performed water change last week.

 

[Jonify]

Nope, no Kalwasser. I'm dosing B-ionic for Cal/Alk and mag.

You remember the last time you checked uptake and adjusted dose? If you're dosing low, you shouldn't have a problem. If you're dosing high, elements start to precipitate out and Mag/Cal/Dk gets out of whack.

 

[NShirke]

@Jonify,

I believe, it was 5ml for cal/alk everyday. Keeping at this measure, I had very low cal, around 360. Alk was at lower end of the acceptable number 8.2ish, I believe. I re-read the instruction on B-ionic gallon.

For Cal/Alk, it says 1ml per 4G everyday. As my tank is 40g, I assumed the numbers are lower due to insufficient dosing. If my math is correct, I should be dosing 10ml instead. So, the 10ml dosing saga started. Now I think, I should be dosing somewhere between 5-10ml. Perhaps, 7ml everyday?!?!

 

[Reeffragger]

Instant oceon regular salt has low mag in that range.. so that might be an issie if your water has high alakalinity to start with.

Alk at 8 is fine.. and thats where you should be at.

For example my alk 8-9 calcium is 460 and mag is 1420

 

[Jonify]

It's possible ... 8.2 alk is pretty good, though, if it's stable right there. Lot's of folks have success at 7.8-8.0, so it's more about what is a stable number for your tank. When you swing from 360 calc to 420-440 calc through dosing alone, your Mag is gonna tank because your corals can't uptake all that calcium so quickly and get you back to stable. If I were you, I'd do a few water changes and let your levels sit for a bit. Monitor alk/ca/mag over a few weeks and notice how it goes, then do small, small changes in dosing to pull levels up to your targets. Your corals would probably rather stability versus perfect, so I wouldn't chase a number. Just go real slow up to your target and see if you can get your tank to equilibrium with minimal dosing. Most of the time, if you go slow, your tank will fall in line. If you go fast to hit a target, your tank will usually swing out of balance, and you won't keep that number.