What to do Ca and Alk out of wack

[Ben1]

Around a week ago abunch of my sps closed up, altough all the acros looked good the porites and montiporas all closed up. I did a bunch of water changes, and in the last week changed 75% of my water. I use RO/DI and IO salt. I also shut the CO2 off on my calcium reactor. Now a week after the problem started some of the corals reopened. Still some of the porites are closed and my pollicipora wont open and is starting to bleach very slightly at the bottom. What should I do?

75 gal tank
Aqua C remora pro.
K2R reactor
2 400 watt 65k MH
3 110 Watt VHO actinics

PO2-0
Nitrite,Nirtate, Ammonia all 0

I just got brand new kits from marine depot yesterday and found

Ca- 485 ppm
Alk-5.6

This must be the problem how should I fix it, the C02 on the reactor is still off.

TIA

 

[Anonymous]

is your alkalinity reading in meq/L or dKH?

 

[Ben1]

sorry

5.6 meg/l
485 ppm

Which is why I am confused, usually high alk causes a drop in Ca, but this time both are high. I will test again tonight.

 

[Anonymous]

What kind are the test kits? When you say you changed 75% of the water, do you mean you changed 25% 3 times, or did you really change 75% of the old water for new? If the latter, that should restore any major deficits of Ca or carbonate. Therefore you should double-check your tests.

Also, consider a polyfilter and or activated carbon in case there is some sort of toxin or metal contaminant that is causing your polyps to react this way. Low Ca by itself shouldn't do that. What is your pH? Does it fluctuate? If it is pretty stable, it is unlikely you have alk problems (at least big problems).

 

[Ben1]

I changed 25% 3 times.

I retested last night, still at Ca 485 and Alk 5.6 meg/l. I am using brand new salifert test kits from marine depot. All of my corals have recovered and have full poylp extension now with the exception of the Pollicipora. It has small buds of polyps that seem to be regrowing, very slowly. The bleaching on it was not uniform but just in one spot on its very base, possibly something stung it. The bleached area has also started to recover.

Why are my levels still so high? My Calcium Reactors C02 is still off, I wont restart it untill I see my levels drop off a bit. Is this a good idea also?

 

[Xphixer2]

So... what is the consensus, I had thought that the levels you are at with 5.6 meg/l alk and 485 ppm Ca, are just fine? Is this wrong? perhaps it was a PH shift? Rich

 

[Anonymous]

I would just leave things alone or maybe do say 10% water changes every day for a week, nothing more drastic than that. If things are recovering, I would be reluctant to mess around any more. Since you have some freshly made salt water, it is a good idea to test those as well to get a good baseline and an idea for the accuracy of the test kits. I have the same Ca2+ test kit and a PhD in Chemistry and I can assure you it is not easy to use, and the color change is a bit subjective. So check you salt stock solution, and deliberately overshoot the end point with the Ca titration so you can get a good idea for the color changes involved.

 

[esmithiii]

FYI- 3 25% water changes are equivalent to 68%

What is your pH, and at what time of the light cycle did you measure it?

E

 

[Ben1]

FYI, the Alk suddenly dropped which I expected. I just thought it would drop faster. When it did I turned back on the co2 on the reastor. Today all have recovered. My Alk is around 3.2 meg/l so I am happy. Doing nothing but leaving off the reactor untill I saw a drop in the Alk was the answer. Thanks for all the replies.

E, Do you have a formula you use to find this out. Thanks for the info.

 

[THillson]

If I may for E, I assume you mean why did three 25% changes not equal a 75% overall change. Assume a tank with 100 gallons volume, the first one changed 25%, leaving 75 gallons of old and 25 gallons of new water. The second time, removing another 25 gallons, removed 6.25 gallons of the newer water along with 18.75 gallons old water. Now you have 56.25 gallons of old water and 43.75 gallons of new water in the tank. The third time you remove 25 gallons takes only takes 14 gallons of old water and removes 11 gallons of newer water from the last two changes. Leaving 42 gallons of old water and 33 gallons of newer water in the tank. Adding another 25 gallons of new water gives you a ratio of 42 gallons old and 58 gallons newer water, a 68% change.