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Kalk Question

425 Views 6 Replies 4 Participants Last post by  crabbness
This morning before I left for work I asked SWMBO to mix up 1 gal of kalk for me, thinking that by tonight I would have a saturated and settled solution. I called this afternoon and found out that she just added the solution to the tank, well sump if you want to get exact. This was 2 tsp kalk and 1 gal RO/DI water all shook up and dumped right in. I told her to turn off the lights and test the PH. So I get home and the tank looks alright but the PH is 8.6. I just did a 6 gal water change, which is all the saltwater I had mixed already. The tank is a 55 with 18 gal in the sump. The fish seem fine although a bit curious why the lights are off already and the corals, all softies, seem to be normal. Now my questions are 1) This isn't going to doom my livestock is it? and
2) Is this going to have any long term impact with the kalk powder/slurry having gotten into the tank?
This just happened so I am going to monitor the PH over the next few hours to make sure it starts to come down with the lights off. Prior to this the tank was at Ph: 8.3, Ca: 380, dKH 8.5, Temp: 82F, SG: 1.024 and ammonia, trites and trates were all at 0. I think a lesson in dosing kalk is in the immeadiate future around this house.

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I really cant help you on the kalk since ive never dosed it, but that ph spike might of affected your snails and hermits if you have any, sometimes people have had all their snails and hermits wipe out due to a ph spike. That really wasnt much of a spike up so i really wouldnt be too worried but if you happen to see a some empty shells thats probably the cause, that small of ph shouldnt have bothered your fish at all, and probably not the corals since you just keep softies. Just check the inverts.
I've had 4+ gal run into my 120 in a pretty short period of time-no problems,a few corals showed signs of stress but were fine the next day. Just dont bring the ph back down too fast and cause more stress.
Ok, thanks for the reassurance. I didn't think it was going to be that big of a deal. Some of the Xenias have tightened up but everybody looks and is acting fine. Can someone remind me what chemical reaction it is that raises ph when the lights are on?

I beleive its photosynthesis?
Algeas consume the co2 in the water and release oxygen and the lowered co2 /more oxygenated water raises the ph
Someone please correct me if I'm wrong
Carbon Dioxide creates carbonic acid that lowers the pH, this is the same principal that a calcium reactor works on. When the lights are on and CO2 is being used by photosynthetic plants and animals, the hydrogen ion content in the water falls creating a larger Hydroxide ion (-OH) to Hydrogen ion (H) concentration. This in turn increases the pH.

Dissolved Oxygen levels have no effect on pH. Temperature however does effectively raise or lower your DO level. The warmer the water the lower the DO and vice versa.

The calcium hydroxide from the Kalk will affect the system only until those hydroxide (-OH) ions are snatched out of solution by natural processes such as aerobic respiration at night.

You should have no long term problems from the incident.

HTH, Pat
Thanks for posting, that was exactly what I was looking for. I was trying to remember which ions were being exchanged for what. Chemistry never was my strong suit. Blue-pinstripe is my strong suit now I guess:)

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