High DKH

[StevenSeas]

Hey Rob do you run anything like a calc reactor? what kinda substrate do you have? livestock?

[acropoorer]

Rob, two part is a buffer and calcium, quit using the buffer part (alk). If your calcium is ok, don't add that either. Over time your KH will fall, how fast will depend a big part upon how heavily stocked your tank is. For example if you have wall to wall acros it will be fast, if you have just a handful of small stonies it will be slower but it will fall. I assume you don't run a calcium reactor as you said you are dosing two part.

After your kH has fallen to say, 10 or 11, slowly start back with the Buffer, but monitor KH till you have tuned the buffer dose for your tank. Personally, I like to run KH in the 10-12 range as I grow a lot of stonies and low KH is much worse than high for SPS.

[StevenSeas]

OK here ill try to break this down as to why I personally wouldnt ever do this or advocate this. Ok so dkh or alkalinity is a measure of a tanks buffering capacity. A buffer is something that will auto correct a change in the system. In marine systems our buffers come from bicarbonate. This happens to be what sand/rock/and mostly crushed coral give off to the system a natural buffer system if you will (its how the ocean does it.) pH is a measure of the "power of hydrogen" and acid is more Hydrogen and basic is less Hydrogen. So acids have an excess of Hydrogen and they "donate" them to base which is lacking in Hydrogen. Bicarbonate is a base and when it gets a Hydrogen from the organic acids from fish poop and urine it turns in to an acid because now it has an extra Hydrogen. This is called it conjugate acid because its the same molecule but with an extra proton. So the next time a base is made in your tank the bicarbonate+H (conjugate acid) donates the Hydrogen to the base to neutralize it. The Bicarbonate system centers around 8.2-8.4 so the ideal pH range for saltwater (b/c its that way in the ocean.) So the problem that occurs with purposefully adding acid to a tank is that it donates all their extra Hydrogens the Bicarbonate which then become acidic. This isnt really the problem. The problem is 2 fold:
one if too much acid is added there wont be any more of the basic version of Bicarbonate in your system which will cause the rapid decline in pH.
This graph doesnt fit this exact situation but its as close as i could get. If it was flipped upside down it would be prefect. Change the 3.3 (roughly the start) to 8.3. As the volume of acid added is slowly increase the pH slowly changes until all of a sudden a drastic change occurs (the near vert line on the graph) this is a really quick change in pH that would drop it to roughly the acidity of the acid being added.


One ml too much added and you just hit the "magic point" where the pH changes rapidly. So without a pH probe and a lot of time to slowly add the acid i wouldnt do this.
The other reason I wouldnt perform this method is that the dkh would be lowered b/c the change in bicarbonate however once a base is added all that bicarbonate was changed into bicarbonate+H is now bicarbonate again and you are back to where you started with a high dkh and and in order to get there a rapid increase in the pH.
just my thoughts on the subject. I would leave the high dkh alone unless it really bugs you that you are 4 degrees above what is the normal dkh of the ocean. If you are experiencing good growth as is then keep it stable imo. Also if you have a lot of crushed coral in your system and your high dkh really bothers you that much remove some of it SLOWLY. Sand/crushed coral/LRR/LR all add to the bicarbonate in the system because this is how the ocean naturally buffers its water so we get it as a side effect of having these in our systems. Crushed coral ime and imo is the largest contributor to it. (There is a really good article out there about it and how making artificial reefs and then killing reefs create bicarbonate which leads to the increasing pH in the ocean.)
Your salt isnt to blame here as Sea Chem Salinity salt is tested for quality in every batch and the sats of max and min for each component for the specific batch are posted on the side of each bucket for that batch. Sea Chem has their salt at 10.75 on avg.
If you need anything else explain lmk

[BIGBIRD123]

You guys are trying to make this into a job...too technical. Rob do what Dale told you. I would not try the acid method...it will go done in time. Mine stays near 14 and my corals are fine.

[StevenSeas]

+1 to BIGBIRD I agree it will be gone in time and to just let it be. I too have yet to see ill effects of a dkh in that range

[BIGBIRD123]

Steven, not trying to rain on your parade and great to see someone with the technical aspects but most of us don't understand all that and would probably kill our tank because of it.

[StevenSeas]

lol know I understand. However relating my chem and organic chem to my tank is the only way to help make it make sense to me so I can pass the stupid classes. I was just tryin to point out as to why not to do it, heck if i wasnt in o-chem right now i wouldnt have understood a lot of that but tried to break it down best I could. Hopefully this doesnt cause anybodys tank to crash. But to me I love the technical side b/c I have to know how it works in order for me to understand it

[BIGBIRD123]

Yea, I know. I'm just from the old school. No offense intended but I would take experience over education any day. In my 35 yrs of Construction, experience got more done....lol

[robalv]

hey thanks guys I am home now, hard to read my phone and drive and type back... I was using Seachem Reef Fusion 1 & 2. No I am not running a Calcium Reactor and will stop dosing today... I was told to use both parts to try to control the problem.... I have 7 colonies a few frags of Sps ,2 clams and a few Pallys , Zoas and 13 fish... everything looks great just want to get a handle on things.. I just picked up a Octopus Extreme 200 thanks Brewercm. Stopped the Kalk... I have not done a water change in 2 weeks this coming Sunday usually do 15 gal. total 150 ish with sump, can I or should I do a 40% water change anytime soon? Also my substrate is black reef sand, I know but I thought it was a good move in the beginning, I am wanting to add crushed coral and remove most if not all the black sand a bit at a time, suck it up while doing the water changes.. let me know what you think..

Thanks again

Rob.

[StevenSeas]

can you yes but for what benefit??