Bleaching SPS calused by Alk Swing??

[hilde123]

I had my CO2 bottle run out while I was away on vacation. I was able to note this by the sharp increase in PH in the reactor remotely on my AC3. It was 3-4 days before I returned home and had the bottle refilled. During that 3-4 days my alk fell 6 points from 12 to 6. After the refill, about a week ago I am back upto 10 and rising. All my corals seem OK except the birdsnest, it seems like they are blaching at the base, but the ends of the branches are still OK. COuld this have been caused by the reduction in cal in the 3 days the bottle was empty. Will an abrupt Alk change affected corals, or is Alk one of those chamicals that do not have a direct effect on corals. Also my PH was fine during this staying between 8.4 and 8.0. This is more of a PH swing than I normally get, but doesnt seem to be enough to cause damage.

[crvz]

It can, that's a pretty big swing over a short time. Not much to do, now, just keep things relatively stable and hopefully the coral will recover in time.

[hilde123]

Isnt it pretty normal for the CO2 bottle to run out, without a continuous monitor like the AC3, it would seem that in most cases a few days would go by before it would be noticed. Is there anything I can do if it happens again to keep my Alk from dropping?

[Gary Majchrzak]

a quick glance at the pressure guage on the regulator once in a while will alert you to low CO2 pressure. A rapid drop like you describe (12 to 6 dKH?) in 3-4 days sounds like it would stress certain corals. (Sounds like crazy rapid alk depletion. Why such high demand... got big clams or large coral colonies?)

ATO with kalkwasser should help alleviate such a rapid drop in alk should the Ca reactor go down...

[hilde123]

The tank is a 180, I do have many SPS colonies and two large (4-5") Crocea clams. I read on another post that a fully stocked tanks without supplementation will drop 1-2 DKH per day, so I thought I was in the range. Im using a salifert test kit, thought they were pretty accurate. Is this something I need to be concerned about?

[rigleautomotive]

it all sounds normal to me.i have become anal about checking the guage.the one guage on the regulator will show you the amount of gas in the cylinder and the other shows the pressure going into the reactor so when you see the guage that shows the level in the cylinder going down close to zero you will have a day or 2 to get it filled.I use a larger cylinder so that happens less frequently.my alk will drop 2 to 3 dkh daily without it working so i make sure i get it done before its out.also sps IME str/rtn with shifts in alk greater then 2 or 3 dkh so its quite possible this is your cause.good luck

[Gary Majchrzak]

many SPS and large clams explain the rapid depletion.

Salifert tests are fine.

[snorvich]

I agree, except I use Elos because they are easier to read for me.