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View Full Version : Extremely high dKH level!! What to do?


warfanax
03/28/2012, 04:24 PM
I was having problem with my pH being 8 and I started to add sodium carbonate (API proper Ph 8.2) to buffer my saltwater. However, my stupidity is I didn't test my dKH while doing this. I have been adding this everytime I wanna increase the Ph.

Finally I bought an API test kit and it showed 22!! I was so freaking surprised. I know that its suppose to be around 10-12 dKH.

I have been running the tank like this about a month and for the last 2 weeks I lost 3 snails and 3 hermit crabs 1 cleaner shrimp. And rest of the crabs are not dead but they don't move at all just sitting inside their shells all day. I don't know if their death is related to hardness.

I now have a cleaner shrimp and seems like doing fine. It has been 6 days since I got him.

My calcium is 320ppm btw which is ok for a Fowlr tank.

is this hardness dangerous? Will it go down on its own with the precipitation of calcium?

I also mixed fresh saltwater and it showed 13 dKH so I assume test is not wrong.

I did a 10% water change but it still shows the same hardness. I don't wanna do it more because 5 days ago I did 30% and I am afraid it can effect my bacteria.

My fish are doing fine but I am worried if this can kill my shrimp.

What do u suggest? Should I dose Kent liquid calcium to bring the hardness down with precipitation?

info about my system.
10g Fowler tank
Use RO water
Ammonia 0
Nitirite 0
Nitrate 10-20
Ph 8.2
Calcium 320
dKH 22

disc1
03/28/2012, 04:33 PM
If it's a FOWLR then it's not going to use up alk very fast. Do water changes to bring it down.

In a reef I wouldn't worry with pH of 8, that is a fine fine number. In a FOWLR I wouldn't give pH much of a thought.

And never add buffers to adjust pH. They will throw out your alkalinity every time.

warfanax
03/28/2012, 04:41 PM
I did more than 30% water change 5 days ago (added carbonate buffer though) and yesterday 10% (to decrease dKH). so if I do 30% today will it negatively effect my bacteria?

And how come my hardness is super high but my ph is still showing 8.2? when I add sodium carbonate to the test tube to see how high concentration of carbonate effects pH, it shows more than 8.6.

brandonb8
03/28/2012, 05:03 PM
How long has the tank been set up? Not to be a jerk but it seems like you are new to the hobby. Any reason you went with such a small water volume. Things tend to fluctuate very rapidly with that small of volume of water. Is it possible for you to go bigger. I think in the long run the water column will be more forgiving and lead to longer lasting success. This isn't to say a 20 gallon isn't manageable, just that it doesn't take much to get your parameters out of wack

Sent from my PG86100 using Tapatalk

disc1
03/28/2012, 05:24 PM
I did more than 30% water change 5 days ago (added carbonate buffer though) and yesterday 10% (to decrease dKH). so if I do 30% today will it negatively effect my bacteria?

Bacteria in the rocks. Change all the water you want. Make sure not to change parameters too drastically all at once. A pH change of a few tenths of a point is not a big problem.


And how come my hardness is super high but my ph is still showing 8.2? when I add sodium carbonate to the test tube to see how high concentration of carbonate effects pH, it shows more than 8.6.

pH is a function of alkalinity and CO2 concentration. When you're trying to adjust pH with buffer, you are raising the carbonate concentration. Since carbonate makes up the primary buffer in seawater you are making that buffer stronger. So now it takes even more buffer to change the pH, leading to an even bigger jump in alkalinity. It turns into a vicious cycle. All the while, CO2 is pulling the pH back down.

The secret is CO2. If you really feel the need to raise the pH, and I don't really think you should, then you need to first get the alkalinity in line and then work on getting fresh air into the tank to help lower the CO2 concentration.

In a reef tank, you have a lot of photosynthetic organisms that turn CO2 over into oxygen. But in a FOWLR you really don't, so CO2 concentration gets a little higher and the pH runs a little lower.

Seawater is a pretty strongly buffered system all by itself and it will maintain a pH over a range of about 0.5 pH unit either side of 8.2 or 8.3. Any pH in this range is safe for a reef and more than safe for your fish. Unless you are running a calcium reactor or dosing high pH alkalinity supplements or kalk (all things related to keeping coral), there is really no need to even think about pH.

warfanax
03/28/2012, 05:32 PM
Yes I am new to the hobby. Its been little more than 2 months since I started running. I didn't know the importance of tank size while buying it. Yes I am planning to change it to a 30g tank soon but not now. 1 bedroom apartment is small enough for me and my gf and we are planning to move to a bigger one so when we move I will get 30 :-D

warfanax
03/28/2012, 05:34 PM
Bacteria in the rocks. Change all the water you want. Make sure not to change parameters too drastically all at once. A pH change of a few tenths of a point is not a big problem.




pH is a function of alkalinity and CO2 concentration. When you're trying to adjust pH with buffer, you are raising the carbonate concentration. Since carbonate makes up the primary buffer in seawater you are making that buffer stronger. So now it takes even more buffer to change the pH, leading to an even bigger jump in alkalinity. It turns into a vicious cycle. All the while, CO2 is pulling the pH back down.

The secret is CO2. If you really feel the need to raise the pH, and I don't really think you should, then you need to first get the alkalinity in line and then work on getting fresh air into the tank to help lower the CO2 concentration.

In a reef tank, you have a lot of photosynthetic organisms that turn CO2 over into oxygen. But in a FOWLR you really don't, so CO2 concentration gets a little higher and the pH runs a little lower.

Seawater is a pretty strongly buffered system all by itself and it will maintain a pH over a range of about 0.5 pH unit either side of 8.2 or 8.3. Any pH in this range is safe for a reef and more than safe for your fish. Unless you are running a calcium reactor or dosing high pH alkalinity supplements or kalk (all things related to keeping coral), there is really no need to even think about pH.

Thanks alot for the awesome explanation. I will do a water change tonite...

bertoni
03/28/2012, 08:11 PM
I am not sure that 22 dKH is high enough to kill the animals you mentioned, but I agree with doing some water changes to reduce the level. I might do 2 15% changes in a day, rather than 30% all at once, to reduce the possibility of shock.

warfanax
04/07/2012, 09:34 PM
I did 15% water changes 4 times and my dKH is 18 now. Still not low enough to be optimal. Frshly mixed saltwater is 14. I need to keep changing I guess

agruetz
04/08/2012, 12:13 AM
If newly mixed salt is 14 dKH then maybe you need to double check your test? What salt are you using? Mine is usually never more than 7 or 8. I normally have to dos 1ML per gal of Reef Code B. Just some advise on the 10G tank, SLOW SLOW SLOW, small changes can have HUGE affects, make sure you double and triple check any math on any dosing because the dosing on the bottle is rarely for a 10G tank. My first tank is a 10G too, I have had mine for about 5 months now. It is entirely possible I recommend lots of research over filter a lot and very very small changes because things go wrong quick in a 10G tank. Hope that helps.

bertoni
04/08/2012, 12:17 AM
I agree that 14 dKH seems high. I'd check the SG device and the alkalinity kit.

agruetz
04/08/2012, 12:20 AM
I mean I have seen it happen where alk in a small tank (I did it, I spiked mine to about 15/16 dKH the first time I dos'ed alk in my 10G). However it was back to normal with in 3 days. But definitely double and triple check the tests to make sure it is right. Dosing/changing etc... off inaccurate test kits will absolutely kill you in your 10G tank.