I need a chemist...

1journeyman

Active Member
Ok, I'm currently cycling my tank. I just added about 90 Lbs. of uncured liverock. I'm doing water changes, but the pH keeps dropping like a rock. Is this normal?
 

bang guy

Moderator
In my opinion the water change is beneficial but to answer your question - PH will fluctuate wildly while the tank cycles.
Ignore the PH. Just test Ammonia and do a water change when Ammonia exceeds 0.5ppm. Liberal amounts of Amquel will also help to keep the critters in your rock alive.
 

1journeyman

Active Member
Thanks for the replies.
I want to keep ammonia down to preserve the life on the live rock.
I'll get some Amquel, thanks.
Does adding a pH buffer at this stage help in any way?
 

trainfever

Active Member
Right now the bacteria in your tank are multiplying by the thousands to keep up with the ammonia in your tank. As those bacteria consume the ammonia and turn it into nitrate, other bacteria will take over and turn the nitrite into nitrate. If you do a water change now, you will be throwing away ammonia and at the same time depleting your system of the bacteria that it needs. Your system will only hold enough beacteria that it can handle, meaning all the food that is in there. In this case ammonia. If you throw away the ammonia, your bacteria will stop multiplying until it finds a new food source, more ammonia.
 

1journeyman

Active Member
True.. but while cycling uncured live rock I am having WAY more ammonia than my tank will ever have. I don't need all that ammonia fixing bacteria.
While I understand your point, the ammonia is too toxic at this point. In my opinion, unless you dilute it you kill too much off of your live rock, leading to decay, leading to more ammonia... etc.
I want some ammonia, but certainly not all of it.
 

bang guy

Moderator

Originally posted by 1journeyman
I want some ammonia, but certainly not all of it.

My thoughts exactly. As long as you have some
ammonia then nothing will starve. I never understood the concept of allowing ammonia to kill off everything just to grow bacteria. It seems some people believe that more ammonia grows more bacteria. This isn't the case, if there is ammonia in the water then ammonia is not limiting the population of anything.
As far as PH buffer... no, I do not think it will help. I think it has the potential to disrupt the animals in your system.
Once ammonia hits zero start feeding the tank fish food so that the bacteria you have grown do not perish. Be patient (you are showing patience already) and you will have a thriving biosyustem and
the live rock critters you paid dearly for.
 
K

krustytheclownfish

Guest
I agree with Bang Guy. You hear all the time NOT to do water changes during the cycle, which to me makes no sense. There are a lot of critters on/in lr that will perish if you have high ammonia. The bacteria on lr is only one consideration. What about the bugs and worms and all of those neat guys that you want in your reef tank. They could very well die
. Maintain your tank during the cycle like you would any other time. After all, you have live animals in there. If you can measure the ammonia or nitrite, you have enough.
Oh, I wouldn't use a pH buffer. You'll give yourself a heart attack trying to keep pH steady during the cycling period. Measure ammonia, nitrite, and nitrate during the cycle. After the cycle is over, measure all those other fun things.
 

pelena

Member
Ok here comes some chemistry. But first, what kind of substrate do you have? As this will play a big role in buffering the acid.
If you bought sand at Home Depot or another type of Silica Sand, get rid of it ASAP. Its great for cement work but does nothing for your tank.
Hopefully you have either crushed coral or aragonite sand (prefered-it is the same stuff but much finer than crushed coral, better for the Nitrogen cycle)
You should also have good oxygen in the tank. make sure the surface is rippled or has water breaking the surface (like a hang n the back filter). If not you may have too much C02.
Ok, ready, here is the chemistry.
C02 (carbon dioxide) + H20 (water) = H2C03 (carbonic acid)
this builds and will lower your pH unless...
CaC03 (calcium carbonate=coral rock or sand) + H2C03 (Carbonic acid) = Ca(HC03)2 (which is aqueous, meaning 2 Ca+2 and 2 HC03- ions are dissolved and floating in the water)
The 2 HC03- acts as a base [because 2 HCO3- = 2 OH- (base molecule) + C02 (carbon dioxide)] and will help nutralize future acids in the same way. This is why the pH is slightly basic (>7).
If you have coral rock/sand it may take a little while for the reactions to balance and stablize your pH. Over a long period of time or alot of acid introduction, sand and rock may even "disappear"
(I am now offically a total dork)
 
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