Acropora bleach from bottom up

[aaron7405]

My acro is bleaching from botom up. I heard that it could me couse by high ALk leves. I mede a test and is 11.4 DHK kind of high

should I cut the frag from where is bleaching?
_How can I pull dow the alkalinity leves?

 

[HarleyDude]

That is a little over 4meq/L which isn't too bad. It is best to keep Alk within 7 to 11dKH (or 2.5 to 4meq/L). I don't think this is the reason your acro is bleaching. What is your pH and Calcium? Are you using a Ca Reactor and what other additives are you adding to the tank, make-up water and evap water?

 

[kevinpo]

Hello,
Is the tissue ression slow (over a period of days)? I don't like to see alkalinity over 9.9 dkH for extended periods. Not enough flow can cause slow tissue ression from the base up. Organic compound build up in the water is another thing to watch for.
A 20% water change using RO/DI water will drop your alkalinity. Check your calcium. If it is low you can bring it up to 420 ppm or so and that will also drive down your alkalinity.

Cheers,
Kevin

 

[HarleyDude]

I don't like to see alkalinity over 9.9 dkH for extended periods.

That is interesting. I am usually happy when my alk stays in the upper 3's (meq/L) or from 9 to 11dKH. How do you accomplish keeping Alk this low and also keeping other paramters in check? I am not being sarcastic at all here, simply curious. When everything is "balanced" in my tanks, the Alk is usually upper 3's, pH 8.2ish and Ca around 400. I would like to have pH a little higher and Ca a little higher, but then Alk goes with it.

 

[kevinpo]

How do you accomplish keeping Alk this low and also keeping other paramters in check?

Excellent question. Here is a link to a calculator that you may find helpful in finding the alkalinity and calcium numbers when they are in ionic balance to each other.
http://www.andy-hipkiss.co.uk/index.htm?http://www.andy-hipkiss.co.uk/caalkcalc.htm

There are several ways to boost calcium and/or alkalinity. Generally when you raise one the other tends to drop. So if you want to lower your alkalinity and your calcium is 400ppm add a calcium booster such as calcium chloride to bring the calcium to 420-440 ppm and the alkalinity will drop.
If your calcium is 450ppm and you want to lower it you can add a buffer (usually made of a combination of sodium bicarbonate and sodium carbonate).

PH is really not part of the calcium/alkalinty relationship. My friend Boomer over in the chemistry forum can give you a much better explanation as to why

Regards,
Kevin

 

[HarleyDude]

Very cool link - thanks. I hadn't bumped into that one before. Yes, correct, pH isn't part of the Ca/Alk relationship, but the Alk or TA (Total Alkalinity) affects pH. Trust me, I am not trying to teach you anything you don't know, just explaining why I had pH in the mix.

 

[Katchupoy]

Just want to share also..... I have this page printed and keep it besides my tank....

Calcium/Alk Guide....

Its just a guide I use.

 

[aaron7405]

My Calcium is 400 and my PH is 8.2

 

[SueT]

aaron, if the frag is continuing to bleach then I think it might be best to go ahead and frag it into good tissue. Re glue it and hope that the bleaching stops.

 

[aaron7405]

I did frag it yestarday I hope this stop the bleaching, I will perform another 10% WC tonight. My Calcium parameter is on betewn 380 and 400 I need to put it up to 420 I will use Calcium +3 from Red sea I have never use calcium Add so I hope it could work too.

My calcium levels where ok just with the WC my sintetyc salt is Coral Pro from red sea.

Salinity 4.022
Temp 77-80

 

[Katchupoy]

what is Salinity 4.022? How do you read this and what equipment? Thanks.

 

[stonycorals]

That's new, not including pH when talking about Ca and alk?!?! I guess it's only an issue when trying to maintain higher levels.. For example, try to maintain alk of 10dKH and Ca 450ppm with a pH > 8.4. Ca and alk are so highly saturated abioatic precipitation is highly likely.