kalk and vinegar??

madadi

ReefOG
so i read somewhere that kalk (calcium hydroxide) reacts with CO2 in the water to form free calcium + bicarbonates, great.
BUT, and this is the part i did not know. if you drip too much kalk to keep your pH up, because your running a calcium reactor lets say, without enough CO2 in your water, the outcome of the chemical reaction is not calcium and bicarbonates but carbonates.
carbonates are not good in the water column because it will react with the same calcium you just added to the tank to produce calcium carbonate, an insoluble form of calcium sometimes producing a "snow" affect in the tank. even worse, this is from experience, the calcium carbonate binds with aragonite in your sand turning it into a flat rock! ya calcium reactors produce access CO2 but not enough to prevent hardening of the substrate for me. im afraid to increase the effluent rate as to not decrease the pH further, but maybe thats exactly what i need because the extra CO2 will allow more free calcium and bicarbonates to exist in the water column and stabilize the pH better?

here is the good news if that gave you a headache and the question i want to bring up in this thread for discussion. you can add some vinegar to your RO reservoir to pass trough the kalk reactor, OR just premix the kalk, RO water, and vinegar when you dose and add that to the tank.
apparently, acetic acid (also vinegar) dissolves the calcium and bicarbonates without the limiting factor CO2 at an ideal 1:1 ration. this will prevent carbonates to form, therefore calcium to drop out of solution, hardening your sand, AND lowering your pH further.
sounds perfect, but wait there is more. the left over acetate ions from the vinegar provides carbon for bacteria that feed on nitrates from the water! kind of like vodka dosing. if we can dose a known beneficial bacteria periodically like that in ultralith system to prevent a bad bacteria that can also feed on carbon over taking the tank, its a win win scenario and worth a try in my opinion, or am i way pass my bad time and dreaming up BS.
 
this is the article that sparked my interest.

http://www.reefscapes.net/articles/breefcase/kalkwasser.html

im going to try 20ml per gallon in the top of reservation and im going to see what difference that makes to my tank pH.
im also going to dose the ultralith bacteria to reduce the risk of a harmful bacteria that also feeds on carbon from taking over the system and killing the beneficial bacteria due to prolonged use of vinegar.
 
i could see that happening. i have a huge skimmer that should help and also i will start very slow. im giving this a try because 3 months ago i replaced my sand because it was all a solid brick and now its happening again.

how much did you start off with? thanks
 
Take a look at this article. Randy gives an excellent explanation of the chemical interactions that occur when mixing kalk in vinegar.

http://reefkeeping.com/issues/2005-01/rhf/index.htm

I happen to think there are very few negative consequences to mixing kalk with vinegar and please don't be swayed by the previos post with the link to the tank crash. In my opinion there were many variables affecting that tank and I think the vinegar was not the culprit - more likely that the poorly managed dosing of kalk is what started the spiral which crashed that tank.

I've been mixing my kalk with vinegar for months and have found no ill effects. Good luck.

Jeremy
 
The person that wrote that top article posted above does not mention any of the possible drawbacks to using vinegar. It is not necessarily the win-win situation described. While it can be useful, and is a good way to deal with excessively high pH (above 8.5 or so) or with the cases where a little more potency of the limewater would be good, it does drive bacterial growth.

Whether that is good, bad or otherwise depends on your other husbandry practices, but its impact should not be ignored. It can result in reduced O2 (especially if you add it rapidly), certain visible bacterial growths in some cases, and also possibly in the death of macroalgae.
 
thanks Jeremy, i agree. im really trying to avoid calcium precipitation which is common with kalk dosing and leads to clumping of sand. all the extra benefits are just a plus.

what i don't understand is why is it hard to use vinegar with a kalk reactor. if i add the proper ml per gallon of vinegar to the RO reservoir, that water passing trough the kalk reactor, wont it just dissolve more kalk leading the same result?
 
i think hes talking about the one i posted. its not by randy, and yes it does not mention any negative drawbacks that can result. bacterial growth can be negative if a bloom develops which can rapidly reduce available oxygen in the water. a good skimmer can reduce that risk and can skim out bacteria in the water column. also a less desirable bacteria can bloom killing off the desirable ones we want that are able to reduce nitrates and phosphates. this risk also might be reduced if one doses periodically desirable bacteria like ones available in ultralith system.

does anyone know why you cant use vinegar with a kalk reactor?
i have a RO reservoir from which the kalk reactor draws its water. if i add vinegar to this RO water in the recommended mL per gallon, shouldn't it be ok?
 
I mix my kalk directly with the vinegar then mix it with the RO water. I see no reason why it wouldn't work in a kalk reactor when you dose the vinegar to the RO water. The concept and chemistry is the same as far as I can tell but I guess I can't speak for certain since I don't use a kalk reactor.

Jeremy
 
i would think its fine also but im hoping someone that has tried it makes me feel more certain about doing it that way.
 
f i add the proper ml per gallon of vinegar to the RO reservoir

No can do. It will simply be degraded by bacteria in the reservoir. Then the CO2 that they make from the vinegar will deplete the potency of the limewater.

Yes, I wrote one of the articles posted above, just not the first one that puts a totally rosy picture on vinegar plus limewater. :)
 
well i started to use a little vinegar with kalk in the top off water. and im really happy with the results. i was never able to get my pH higher then 8.05 because i also run a calcium reactor. now just 2 days later my pH is at 8.25 in the evening, 8.1 in the morning! im really glad i tried vinegar. it really helps dissolve more kalk. i would recommend starting out really slow. i started with 20ml per gal and that was a bit high. water got a slight murky tint to it and i could tell it was an bacteria bloom because my snails were all at the top of the water line trying to get more air. skimmer was going a bit crazy and i can see a real white foam and skimmate coming out. fish didn't look stressed at all. no fast breathing. my over sized skimmer saved the day! i would start off with 5ml per gal and 1tsp kalk just to be safe.
 
anybody thinking about the effects of an accumaulating acetate counter ion in the tank (a dissolved organic)?? Doesn't seem that conducive to keeping the algae in check?? Defeat one aspect of RODI treatment??
Rex
 
madadi:

I'm confused. You'd get a bigger pH rise with equal or less limewater without vinegar. Why do you want vinegar?

Rex: Acetate is rapidly metabolized by bacteria (not algae). That;'s why vinegar drives bacterial growth. It leaves behind only CO2 and bicarbonate/carbonate.
 
i am fairly certain that tank did crash from the vinegar. now by crash i mean too much oxygen was removed from the water and everything suffocated in my tank. When i dosed the kalk i kept a VERY close eye on my ph, and it never moved. i used 2 different test kits to ensure proper readings. i did however use a lot of vinegar.

i started with 1 gal ro/di to top off, and added 3 tablespoons of dry kalk and a power head help let it dissolve. i then added vinegar until the ph dropped. now with no buffering in this mixture the ph went from very high to very low with almost no in between. once i got it very close to neutral i added 2 gal of tank water and let it sit for 2 hrs to stabilize. i got the ph of the solution to 8.3 and then added this back into the tank over about 1 hr, testing the ph of my tank every 5-10 min, and after the dosing every 20, then 1hr, then 2hr, then 4hr..... The rest of my tank params stayed normal.

here is the problem. in order to neutralize the ph of 3 tablespoons of kalk it took almost 5 CUPS of vinegar. The following bacteria bloom was so big i could not see anything more than 3 or 4 inches from the glass. so while my ph stayed normal, there was no oxygen in my water. call me an idiot, because i was, but this dosing indisputably killed pretty much everything in my tank.
 
i added just a little vinegar. i think it only dissolved more calcium and bicarbonates. i just know my pH has never been this high before. it was always less then 8.1 because of my calcium reactor. i thought it was only meant to drop pH, and I'm sure it does in higher concentrations of vinegar, but just a little seems to have brought the pH up a bit.

matt_54351 i can see how you could have had a crash from the vinegar. i also had a little bloom from the vinegar but it was gone within a day. good thing i have an over sized skimmer that not only oxygenated the water well but also got rid of some bacteria.

Randy: your not the person to argue with about tank chemistry and especially about something you've write an article on. maybe there are other factors involved, but the only thing i did was add a bit of vinegar and i like the results. i think its a tricky thing to do. if not done right it can have bad consequences like you said.
 
madadi:

Do you mean that by adding vinegar and doing nothing else different (including the way you stir), the pH rose, or that when using limewater plus vinegar compared to not adding any limewater, the pH rose?
 
ive always dosed kalk and used a calcium reactor.
at first, i didn't have a reactor and dosed kalk from an RO tank mixed with kalk. pH never rose above 8.1
i got a reactor that mixed it twice a day with a stir bar and it still didn't rise above 8.1
i took the reactor off line because you said i cant use it with vinegar.
added 20tsp of kalk to 20gal tank of RO water and 400mL of vinegar.
i didn't change the calcium reactor pH, i didn't change the flow rate.
with the vinegar the pH rose higher then before.
i know thats not typical of vinegar use. but i cant figure out what else it could be. im glad my pH is a bit higher now. also my alk rose a bit higher then i wanted it to, 12dKH. i always had it at 10 before. i think ill use even less vinegar and kalk next time i refill the RO tank. maybe reduce it by 20%

it might be that my kalk reactor wasn't giving me fully saturated kalk water.
 
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