Chem Challenge: raise pH lower KH

[mab]

I need to raise my pH and lower my KH at the same time. Any of you seasoned chemistry wizards know how to accomplish this? any suggestions will be much appreciated. Kent Superbuffer just makes matters worse (raises KH and Alk even higher) I tried plain sodium bicarbonate (baking soda) but as you know the raise in ph is only temporary. The high KH is also affecting Calcium levels negatively.
Tank specs: 55 gal reef 5 sm fish, many inverts, live rock, established 1 year, Ehiem Pro, Remora skimmer w/ carbon filtration, UV, 4 powerheards behind Wavemaster Pro. Amo 0, nitites 0, nitrates <15, calcium 330, Kh 17! (want lower 8-10) , ph 7.95, (want higher 8.1-8.3), use RO/DI and Kent Seasalt exclusively.

 

[bang guy]

Stop all Carbonate additives! Use Calcium chloride to SLOWLY raise your Ca levels until it's up to 420. This should take at least a week. If you do this then the PH will rise on its own.
What's happening is you ALK is beyond stable levels. Every time you add more Carbonate it reacts with the Calcium, creating Calcium carbonate, and lowering the PH.

 

[frankl15207]

Bang
Any recommendations on how much calcium chloride to add at a time (ie: 1 tsp . 20 gal)?

 

[slick]

Frank I'm not an expert by any means but my bottle says add 1 teaspoon for each 50g of water every day or as needed to maintain ca levels.

 

[bang guy]

It mostly depends on the consumption rate of your aquarium. If it were my tank I would start with 1/2 tsp in the morning and 1/2 tsp at night and test the next day to see if the level increased. If not I would increase the dosage to 1 tsp morning and 1/2 at night, then repeat the test. Keep testing ALK every day (a pain ) to see what's happening there as well.
Slow and steady! Don't try to fix this overnight. You just want it to get a little better each day.
Remember buffer = carbonate = alk (not exactly, but in general)

 

[frankl15207]

Originally posted by slick
Frank I'm not an expert by any means but my bottle says add 1 teaspoon for each 50g of water every day or as needed to maintain ca levels.
That's what my bottle say too. That's why I wanted to defer to an expert on the subject .

 

[bang guy]

Mab - How is everything working out?
Guy

 

[brooklyn johnny]

I had this exact problem... Here is an article that will help. Adding a buffer is what you DO NOT want to do, because although it will raise your pH temporarily, it will also raise your alkalinity, and eventually result in a lower pH that does not come up as much during the day during photosynthesis. The answer is calcium chloride... Kent makes both a liquid form...
http://www.kentmarine.com/lc.html
and a solid form...
http://www.kentmarine.com/tc.html
I use the liquid one on my 10 gallon nano because although it is more expensive, it is more dilute and easier to measure in small amount with a syringe. If not use the turbo calcium.
Keep in mind that this is calcium chloride, NOT kalkwasser or a two part additive. It will LOWER your alkalinity (what you want) and raise your calcium. After you have the levels you want, you can maintain them with a two part additive, kalkwasser, or both (or a calcium reactor). I switched to kalkwasser which does what the two part aditives do, but maintains a higher pH. The kalkwasser is balanced, but if I ever come out of balance I use the appropriate B-ionic solution (part 1 to raise alkalinity, part 2 to raise calcium). Mind you I found all of this out after setting up a 10 gallon nano after years of having my 180. Small tanks are tougher deal with, because if a change is going to happen, it happens yesterday. Anyway here's the article pertaining to this (thanks twoods)
http://sps.reefkeepers.org/Alkalinity.html

 

[mab]

Thanks for the follow-up Guy. I have been slowly adding calcium daily but the KH is still holding steady around 17, he ph is at 8.05 cal still low at 340.

 

[brooklyn johnny]

Mab have you done any water changes? By the way have patience. A smooth transition is the best here, as your corals are in no immediate danger.

 

[mab]

The last water change was a 20% (over the weekend) I will do a 50% as a very last resort and only if the ph drops below 7.9, meanwhile, I keep adding small amounts of calcium and stay away from buffers of any kind. What do you think?

 

[brooklyn johnny]

That is perfect. If you don't have it already, I highly recommend digital pH monitors. They are just under $100, but very much worth it, as you can always monitor your pH day and night with a simple look and you are not left there saying... is that 8.0 or 8.2... or 7.8 Anyway, if 7.9 is your low before the lights come on that is nothing to worry about, but if it is your high at the end of the day it should definately be cause for concern. Stick to the water changes and the calcium chloride, and keep doing it GRADUALLY. This is no emergency. Good luck. As I stated before, don't be intimidated by the use of kalkwasser. When all of the dust settles you may want to look into using it, as that was the long term solution to my low pH blues. Don't start that while your alkalinity is high though. Good luck and you are on the right track.

 

[mab]

BJ,
Thanks again for the great advise. I just ordered a PinPoint pH monitor on sale from Jeff's Exotic Fish for 75 bucks. Does the kalkwasser need a doser or can I just add it with replacemnt PO/DI water each day? I don't think I can deal with anymore machines/gadgets. What brand of kalkwasser do you recommend?
Thanks again, great board!