Small areas of live rock turning white. 2/17/04 Dear sir,  Tank You for your great site. I ve been  through the faq 's but couldn't find any answer for my problem with my FOWLR tank.  It's a 125 Gallon with wet dry filter under the tank with bio balls and Protein Skimmer and lots of live Rock. Fishes: 2 Ocellaris,1 small Picasso Trigger ,1 Yellow Tang 2 small Snowflake Eels,2 Bubble Tip Anemones .  All my readings and test are fine salinity 1.022,Temperature 24 c, PH 8,1-8,3 , Ammonia 0,Nitrate 0-5,nitrite <3   ,.I did a % 25  water change yesterday with RO Water. I do it weekly)  My problem is that some small  places of my life rock Mainly on the purple algae) are  turning white. Can you help me out here. <You did not list values for Calcium or alkalinity.  Both are very important for the health of coralline algaes.  Water movement is also very important.  I would be surprised if they are low if you really perform 25% weekly water changes, but I would check them.  Too much or too little light can be an issue as well, but lighting adequate to maintain a BTA should be adequate for corallines.  Also, some corallines will die out because conditions aren't favorable, and other varieties will replace them.> Thanks for being there. I nearly spend 2 hours a day at your website :) <Glad you enjoy WWM!  Best Regards.  Adam>

Understanding Calcium and Alkalinity 7/31/04 Cheers, Todd Sorry for the delay in reply... been keeping quite busy over here :) > wanted to drop you a line and thank you once again for helping me! after quite a long time I think I finally understand the relationship between ph, alk. and calcium and their importance to each other. <excellent to hear!> I wonder how many people out there who have been keeping saltwater tanks for years do not still understand the importance of how these three things work in conjunction with each other? not to say that > I have become some pro, but I do believe after I went back and read you coral propagation book again, I now think I can sleep knowing that what I'm doing in the tank is right. I reread the "marbles analogy" again and again and went and got some accurate testing supplies. wow! thinking of water parameters within the context of that analogy opened my eyes like never before, so I had to write and thank you for writing in a style that even aquatic morons like me can understand. <Hey... I resemble that remark <G>. Quite welcome my friend. A fave Emerson quote of mine, to paraphrase, "Nothing astonishes men so much as common sense and plain dealing." I give it as I like to receive it.> I started testing again and was I surprised that what I thought was a good regimen was completely bad, well maybe not comp! > lately, but far off course. I never understood that if you add something in many cases you are displacing something else or lowering it to a not so good point. I never realized that water can only handle so many dissolved substances before you get to the point of diminishing returns, refrigerator and took a look at the contents of as box of baking soda and saw the ingredients. sodium bicarbonate, an acid neutralizer! <bingo... you win the hairy kewpie doll <G>> and thought what does alkalinity measure? your waters ability to neutralize acid so that your ph level doesn't sway to much back and forth. I know bicarbonates are only a part of alkalinity but you can understand that the wheels were turning in my head now. <yes... indeed> I started a new regimen about four days ago and these are my readings as of today.nh3-0 nh4 0,no2-0 no3<10ppm ion,alk.6meq/lph between 8.2 and 8.4,ca.345,salinity 1.026 I believe I can tweak the calcium up a little to maybe 380 to 400 and that will drop the alkalinity to about 4/5 meq/l, that is where by the literature! <exactly... your Ca is no biggie... but that Alk is still scary high> > e I want to be? I now hope that I have a good plan and I also have been changing water twice a month and keeping my skimmer clean, I also add Combi-san once a week for trace element replacement. please tell me if I have learned well  or do I need  to go read some more? cheers, Todd Biondolillo <it sounds like you are quite on track my friend. Keep on live rockin in the free world :) Anthony>

The Calcium and Alkalinity Dance Hi, <Hi there! Scott F. with you today!> I've read through all your ca and alk faq's, but I want to get a couple things straight. First off, I have a 220g FOWLR and my most important worry is my fish. I want to keep a higher dKH for ph stability, say around 12? <Sounds good to me...> But I also enjoy good coralline growth and have a good supply of all types of supplements for calcium. <Careful! Haphazard or mis-applied dosing of calcium supplements can degrade alkalinity and really throw the ionic balance of your tank water out of whack. ALWAYS test for calcium, pH and alkalinity when using any calcium supplement> I realize the target Ca level could be anywhere from 350 to 450, but I'm scared of the snowstorm effect and precipitant damaging my Euroreef skimmer pumps. What should I aim to keep my calcium at? <In a fish only tank, 300-350ppm is a good target, IMO.> what confused me was an online reef chemistry calculator that said a balanced ca level for a dKH of 12 was 450 and the balance for calcium grew larger as each value for dKH grew larger. I read here that each are "mutually exclusive" so what does this balance mean? and what should mine be for my application? <Good questions, and there are many thoughts on this. Personally, I would not be overly concerned about Ca levels in a FOWLR tank. I'd be more concerned about alkalinity (buffering ability of water), since fish are heavy eaters and excreters, capable of driving down pH with copious amounts of waste products. even as a reef enthusiast, I think that it's not a great habit to get into- trying to shoot for a specific "target" number. I'd accept high alkalinity and a lower calcium level, especially if the inverts tend to be doing well. Let your animals be your guide here. Regards, Scott F> http://www.kademani.com/reefchem.htm thanks, Brandon

Calcium/Alkalinity Dance Hi there Crew, I keep wanting to ask you more &more. <Ask away!> Sometimes I cannot believe I found this site. Many times reading The "Conscientious Marine Aquarist" I have often wondered wouldn't it be great to have a website on these lines? I do thank you, each and every one of you, for the guidance and support you have given me so far. <Thanks for the kind words!> So here we go another question (or three) Calcium 260 ppm.......??? How can I safely raise the calcium quickly and why is the KH and Alk as high as they are? <I'd recommend proceeding slowly when attempting to make any environmental changes in an aquarium. High calcium and high calcium levels are almost mutually exclusive in most aquariums. It's a balance, basically- and you'll want a reasonable calcium level and a reasonable alkalinity reading. I'd recommend using a balanced two-part calcium/alkalinity additive, like C-Balance or B-Ionic. Both are very effective if instructions are carefully followed> Is this simply a case of bad husbandry and overfeeding? In which case I need a new back ! But hell, what do you do in a circumstance like that?....as a result I lost my job so things really are difficult at the moment. I'm not saying that to whine, but as a genuine question to you as to what to do when something like this happens......per-lease do say sell the fish !! Mind you I have never had fried batfish ! Cheers to you all You are a great bunch. Simon <Hang in there Simon! I have a feeling fried batfish taste lousy, although I must say that triggerfish do taste pretty good! You could either use the aforementioned two part additives (although they can get pricey), or your could begin careful additions of Kalkwasser, and measure the calcium and alkalinity levels as you go...A relatively inexpensive and simple way to go! Good luck! Regards, Scott F>

Calcium and Alkalinity I have had fish only for 3 years (40g, skimmer, Whisper hang-on power filter) and over the last month or so I've added LR and better lighting for my LR. I will keep it a FOWLR for the next couple years so you know what my requirements are - until I finish law school and hopefully start making some cash so I can move into reef (law school leaves little time or money for this hobby, but I'm trying). <Be patient, the "good stuff" will certainly come with your continued hard work!> My macro algae is dying off (I can see the crusting "shell" slowly disintegrating away) and I suspect that my calcium is low. <I assume you're talking about Halimeda or other calcareous algae> I would love for my entire tank to flourish with coralline and other encrusting macros! I will be purchasing calcium and alk test kits very soon (and I shall know for sure), but my question is about the best way to raise it safely. My ph is also a little low, about 8.1, and has been around 8.1 for the entire 3 years I've had my tank.  Since I've stuck with hardy fish only, and it's been very stable, I haven't done anything to raise it. So I was thinking Kalkwasser would be beneficial to boost calcium, raise ph, and improve skimming to boot. Do you think this would be the best thing for my system and goals, or should I go with a different calcium supplement? <Frankly, I think Kalkwasser, properly administered and monitored, will do the trick!> From reading through the site, I also understand that it is necessary to use Kalk in conjunction with bicarbonate, since calcium carbonate is what is needed by corals (or in my case encrusting macro). I don't know if I completely understand alk and carbonate (never big on science, but it is needed for this hobby and I'm trying to learn). Is the alk an indicator of the levels carbonate in the water - so if my alk readings are within the optimal ranges of 7-12 dKH, my carbonate levels are adequate? <In a very simple nutshell- yep. It's a measure of the buffering capacity of the water. There is a very important dynamic between calcium, alkalinity, and ph. You need to understand the relationship. There are a lot of good resources regarding this dynamic on the wetwebmedia.com site (and with a lot more detail and better descriptions than I can go into here). Do check them out!> If I add marine buffer (which I understand to be mostly, if not all, sodium bicarbonate) with my bi-weekly water changes, would this be sufficient for my needs? <Well, it depends on the dKH reading of your water, but this is a good practice if it' necessary> Thanks for the time.  You're always good help in a hobby where good help is hard to find. <And thank you for stopping by! Good luck! regards, Scott F>