Supplementing Limestone Flour?   8/14//08 Hello Crew, After Googling my head off, I'm having trouble finding an answer. When searching for calcium carbonate alternatives, I've come across a product called limestone flour. Can this be used, dissolved in water, as a calcium/alkalinity supplement? <Mmmm, nominally, yes... practically? Not likely... just not very soluble> "Chemical" supply companies seem to have better prices on "high purity" ground limestone than dedicated marine suppliers. Would this also help supplement the biominerals deficient in calcium chloride? <Mmmm, no... not really... as in other than calcium and bicarbonate... there is nothing else in Limestone... Where would Magnesium for instance come from?> I Googled limestone flour/ground limestone in conjunction with calcium carbonate supplementation and didn't get a conclusive answer that it's a viable alternative. Would this be approximately the same solution to the Tropic Marin Bio Calcium? <Is similar in principle make-up, but...> My setup includes a 120 sps reef with two 110g basement sumps. The first one is filled with live rock that flows over into a second one (filled with a DSB, some rock, and Chaeto) and back up stairs. Just always looking for a better/less expensive way to add calcium without the investment in a reactor. Thanks as always for your help. Without your site...success would be more of a delayed gratification. Jeff <Would like to make a few statements. The use of finely ground CaCO3 can/could be useful, economical IF you had a large, let's say commercial grow-out system of high biomineral use, along with supplying other needed materials. In practical terms however, for the small volume/need you have, the best (cheapest, simplest, most-reliable) method of supplying alkalinity and biomineral content is some sort of reactor... can be DIY made... I would NOT just supplement (alone) this flour... but it's worth experimenting to prove to yourself the value in using "balanced" means of supplementation. Bob Fenner>

Re: percula clownfish eggs about to hatch... and DIY suppler of 2 part SW supplement for Ca and Alk   4/29/08 Hi, and thanks for the help on my serendipitous clownfish spawn (hoping the hatch is not before Friday). You asked about my "home-made" two-part additive. Actually it is just the basic kit from www.bulkreefsupply.com. For about $50 I have a lifetime supply of calcium supplement plus alkalinity plus magnesium occasionally. Highly recommended. Thanks again, Malcolm Young <Thank you for sending this along. BobF> Maintaining Calcium, Alkalinity, & PH + Homemade Fish Food -12/19/2007 Hello WetWebMedia, <Hi, sorry for the delay...> I am currently using B-Ionics Part A & B to maintain alkalinity at 8.3 dKH, calcium at 340 ppm, and PH daytime 8.27 nighttime 8.37. <It rises at night? Huh. Usually the opposite is the case.> I would like to house hard corals at some point, but I believe my calcium needs to be much higher. <It depends on what type of stony corals. 400ppm is enough for the slower-growing "LPS" corals and such.> Not certain how to make that happen. I have a 90 gallon tank with a 20 gallon sump. I add 20 cc's of part A and 50 cc's of part B each morning to maintain these levels. <Two part solutions are great for smaller tanks, but they're not so helpful in larger systems. You're likely going to have to start dosing Kalk and/or calcium chloride and baking soda (more likely some combination of all those).> I wonder if there is another means by which I can increase calcium without adversely affecting my alkalinity and PH. I am almost out of B-Ionics. Would you suggest I continue to use B-Ionics (which isn't cheap), <No, because, like you said, it's not cheap (thus good for small systems where you don't need much, but unreasonably expensive to use for larger systems).> or would it be better and more cost effective if I switch to Kalkwasser? You can either switch to Kalk or start using Kalk in addition to the two-part solution. It's up to you. Try different things (slowly), always measuring your calcium and alkalinity. Don't change anything too fast.> Just as an aside, I can't afford a calcium reactor. <You don't need one.> Also, I'm thinking of making my own fish food because my LFS does not always have what I need in stock. In addition to adding shrimp, sea fish (any recommendations?), clam, squid, clams/mussels, flake food; I was think about adding Green Food Feast powder. Here is a list of ingredients: Spirulina, chlorella, alfalfa leaf, nettles leaf, dandelion leaf, cilantro leaf, bladderwrack, kelp, Irish moss, wheat grass, barley grass, oat grass, rose hips, broccoli, cabbage, kale, spinach, red clover blossoms, bee pollen, acerola berry extract, cranberries, licorice root, and ginger root <I'm not sure about all the terrestrial vegetation you got here. When I make "veggie" food I only use seaweeds (typically sold in Asian food markets or those high-end new-age places like Whole Foods). For some tips/info on making your own food: http://www.wetwebmedia.com/feeding.htm and here http://www.asira.org/feedingyourtanks> Is there anything listed that would be harmful to my tank inhabitants? <It's hard to say... I think you have some things in there that are "untested"/"un-reasearched" for use as marine pet fish foods. There's nothing that stands out to me as obviously potentially toxic (though I could be wrong). But in any case, why use things like bee pollen?> I have a Yellow Tang, Kole Tang, Royal Gramma, Engineer Goby, Pink Spotted Goby, Coris Wrasse, Dispar Anthias, BTA, Rock Anemone, Star Polyp, Torch Coral, Candy Cane Coral, Mushrooms, Xenia, Cleaner Shrimp, Fire Shrimp, Coral Banded Shrimp, Emerald Crab, Sally Lightfoot Crab, Red Fromia Star, Brittle Star, hermit crabs, and snails. Thanks, Jackie <De nada, Sara M.>

Candycane skeleton disintegrating   8/22/06 Greeting from Nova Scotia <Hello from San Diego, CA> I have a small coral reef tank since 9 months that causes no troubles. One of mine Candycanes got now about 11 branches (had 7 or 8   when we got it) and it's doing really good (dividing, long tentacles at night, bright colours, etc...). Two days ago however, I noticed   that 2 of the branches are actually disintegrating. I am talking about the skeleton at the back of the polyp, and surprisingly enough, the   polyps at the end of those branches are looking awesome and do not seems to be bothered at all. I am suspecting a lack of Calcium and/or   the fact that my pH might be a bit too low (7.8/8.0) <Could be more...> so it drives the carbonate equilibrium of sea water toward the HCO3- side but I am not sure. A friend of mine (has a big coral reef tank) said that it might   be the fact that my Candycane is submitted to water flow that are two high. <Another factor> I doubt it, but do you have any suggestions ? Thanks so much in advance Flavienne <Mmm, the ultrastructure of the alkaline earth skeletal matrix is likely "missing" something... happens frequently with (your as stated) imbalance of calcium, magnesium and alkalinity... Do you have the "Kalk habit"? This is a common situation (soft skeletons) with this use... other methods of supplying ready alkaline earth, carbonate produce "harder" bio-matrix (calcium reactors, two part supplements...). Bob Fenner> -------------------------------------- Dalhousie University Department of Oceanography

Mixing Kalk and carbonates, bicarbonates...  11/12/2005 I have been trying to get my water right before I start my Kalk, drip, my ph 8.2 my cal, 400, but my alk is 0.23 ml's it need's to be 2.9.  I am using C-Balance A & b how do I get my alk right? <There are a few ways... but, are you aware of the mis- mixing of these materials?> I need some help please. thanks Brent. Oh I am using Salifert test kits, I want to get my water quality right before I start dripping Kalkwasser, My ph is at 8.2 my calcium is at 400, but my alkalinity reads 0.23 in ml's i am using two little fishies c-balance a-b how do i get my alkalinity to 2.9 <... please learn/use proper grammar... I's not "i's", company names, their products are proper nouns... capitalized. Oh, and read here: http://www.wetwebmedia.com/calcalkmar.htm and the linked files above until you understand what you're doing. Bob Fenner> 

Beginner w/Soft Corals, actually marine alkalinity, biominerals Hello Crew, I hope that you are able to respond to this email as none I have sent previous to this one have been answered. I have been reading your website extensively but the more I read the more confused I get. I am a beginner trying soft corals and need your advice. Tank Facts 55 gallon w/2 clownfish only and 50 lbs live rock EV 120 Protein Skimmer and no mechanical filtration Tank and top off water from SpectraPure 5 stage w/new cartridges Tank is 1.5 years old Water changes 10 percent weekly Ammonia 0 Phosphates 0 Nitrates 0.05 Temp 76-78 Lights VHO 95 watts each bulb. One white actinic and one super actinic PH 8.2 dKH 8 Calcium 310 (LaMotte test kit) <Too low> Additives: Dose according to package. 2 capfuls of Kent Liquid Reactor Daily 1 capful of Kent Liquid Calcium <I'd switch brands... to SeaChem... Bob Stark's ESV...> Soft Corals: One pulsing Xenia, mushroom and yellow polyps, green star polyps My problem is that I can't seem to raise my PH and Calcium to the desired range for corals which is supposedly 8.4 - 8.5 for PH and 350 to 450 calcium. My xenia is pulsing and my other corals seem to be open and doing well. <... read on WWM re this issue... only a few possibilities> I have read a lot about the dangers of long term use of Liquid Calcium but I am confused as to how to safely get my calcium and ph factors up. I am a bit afraid of additives and get so much conflicting advice ! <Dedicate yourself to study... thinking about this situation... go with other brands. Bob Fenner> Is Reef Buffer any better than baking soda? Am I gaining anything by using a product like Seachem Reef Buffer instead of plain baking soda to raise the PH of my RO/DI water prior to mixing in the sea salt mix? << Yep, but not much.  I know Chemical Jon very well and I've heard his spiel on this.  You can mix baking soda and washing soda together (like 6 to 1 baking to wash) and get about the same thing.  He likes Boron and Borates in his buffers.  Anyway, it isn't much different.  If I had a big tank or system, I'd just use baking soda.  But if you have a 5 gal nano tank, you might as well just use Reef Buffer products. >> <<  Blundell  >>

Biominerals In Closed Aquaria - 12/27/03 Hello Guys: <Hi Joe.  Adam here today.> I don't' know what I would do without your site.  I read for hours and have recently been reading FAQs and information on biominerals. <Glad to here you are benefiting from the site!> Running a 240 Gal tank (octocoral & LPS) with 100 gal sump and non-lighted DSB Refugium w/8"Argonite (for NNR).  Salt mix is IO with RO water (no additives of any type).  Water changes are performed on a strict regimen at twice weekly (Wednesday & Saturday) at 15 gallons per change. I tested baseline biomineral water parameters of Ca 200 ppm, Mg 360 ppm, Alkalinity 2.29 meq/L, SG 1.023 and pH 8.18.  Test kits for minerals are Salifert. Salinity and pH measured w/ Pinpoint electronic meters.  These baseline parameters were consistent for months.  After reading, I have been trying to increase the biomineral content and alkalinity of my system.  I supplemented with ESV B-Ionic Buffer 2 Part System and ESV Magnesium.  The recommended dosing regimen was followed and now my biomineral parameters are decreasing. Measurements are: Ca 150 ppm,  Mg Not detectable and Alkalinity 1.94 meq/L. The only parameters which increased were pH and SG. Now pH 8.4 and SG 1.026. <B-Ionic and similar additives will indeed raise your SG.  B-Ionic alkalinity component is also has quite a high pH.  If this tank ran for a long time with no calcium and alkalinity supplement, I would believe your baseline numbers and that you would have a hard time raising them.  However, I have a very hard time believing that your Mg could be so low.  The instructions are sometimes a little confusing on Salifert kits, and it is sometimes hard to see the color change.  Also, the recommended dosing for B-Ionic are for maintenance and are a bit conservative.  It could take very large amounts to correct the values you reported.> I  did not find any precipitates lying around.  My DSB is not compacted nor shows any signs of binding with the additives. I was confused, so I ran an experiment in my sea water storage container.  The same scenario occurred. <A good experiment!  Were the baseline levels in the newly mixed water OK?  Perhaps you got a bad batch of salt?  Was there precipitate in the salt water container?  Did your salt mix get wet?  Precipitation can occur right in the mix if it gets wet.> After addition of the supplements, all mineral content decreased, alkalinity decreased and pH as well as SG increased.  The only explanation I can think of is that the Mg is bonding with the carbonates thus removing both free Mg ion and alkalinity from the water. <This can happen, but only at high pH.  Also, it would be nearly impossible to pull the Mg down to the levels you reported.  Also, B-Ionic contains Mg (as well as all other major and minor elements).> Why then is pH increasing? <The high pH of the B-Ionic.  This is totally normal.> What do you think?  Other aquarist seem to have excellent results with ESV Supplements. <Indeed.  I have used ESV products and hold them in the highest regard.  I suspect that you may have a testing problem (please do always verify suspect test results with another kit, and even another tester!> Can you please provide me with some suggestions.  I was thinking of using a Ca reactor but fear the same chemical reaction in my system. <If your test results are confirmed, verify that your salt mix is OK, replace it if it is suspect, and proceed with a few large water changes to get back on track.  At that point, be sure to keep up with Ca and Alk with normal supplementation.  A CaCO3 reactor would never lead to your current situation, but a CaOH (Nilsen) reactor might if terribly misused.  In the long run, a CaCO3 reactor is much more cost effective than B-Ionic, especially for such a large tank.> Thank you for your time and much needed help.  Joe <I hope this was helpful.  Adam>

- Procuring Test Kits, Follow-up - WWM, Hello. I finally received my Salifert Calcium, Magnesium, and KH/ALK test kits. Here are my results: Magnesium- 1410 KH/ALK- 16 dKH Calcium- 450 I also tested last week with slightly lower calcium. I added SeaChem's Reef Advantage Calcium to raise it slightly. The magnesium also seems good to me. About the ALK....HOW DO I LOWER IT? It seems WAY to high? <It is high, but not dangerously so.> A few weeks ago (before I had test kits) I added two capfuls of SeaChem's Reef Carbonate, which I believe caused the tank to become very cloudy.  Could this cause the extremely high dKH? <At the very least a factor if not the direct cause.> For additives I have SeaChem's Reef Advantage Calcium, SeaChem's Reef Builder, SeaChem's Reef Trace, and Epsom salts. I have only added a small amount of Reef Advantage Calcium to raise the calcium slightly. I have not used the Reef Builder or the Epsom salts. How often should I use the reef trace? I have a feather duster, toadstool leather, polyps, mushrooms and 80 lbs of HI rock live rock in a 75 gal tank. <At this point, I would add nothing - no additives - except regular water changes. Give your alkalinity a chance to come down a notch or two.> Also, I am considering upgrading my lighting to Custom SeaLife Power Compact with Moon-lite 4x65.  I can't afford VHO, and this seems like a good alternative? <Yes, is a worthwhile fixture.> Thanks <Cheers, J -- >

Alk, Ca and pH woes!!!  Hi guys,  It's been quite sometime since I've asked you guys any advice.   However, now I have a problem. Over the past year my tank has become quite abundant with SPS and over the past month, many of my more sensitive Acros, Staghorns, etc... have started to bleach at their bases or the base of numerous branches. I've even lost a few smaller ones or frags completely. I think I waited too long for a Calcium reactor. Up till now, I was only using a Kalk/Nielson reactor hooked up to my RO unit which is fully automated to add as evaporation occurs. It's obvious that I'm at the point where my system is in need of more than the Kalk can supply through top off. I have a reactor on order from a local guy who builds DIY things at the most professional level. It will be modeled after the ProCal unit.   In the meantime, I have been doing the following to no avail. I've been doing many water changes, adding Seachem Reef Builder for my Alk, Reef Complete for my Calcium ( but have now switched over to Reef advantage since my tank of 175 gallons is consuming way too much and it's costing a fortune) The problem is this. I have no problems attaining the proper levels.., I can add to get a DKH of 11 or 12 ( whichever I choose) in a dose, I can reach 450 if I choose for my CA. but within about 4 or 5 hours, my ALK can drop to around 8 or 9 and my CA. can drop to 380 or 390 in a 24 hr period. My PH is never getting higher than 7.99!!! Even if I try dissolving some Kalk directly in RO water and adding it in the current in my sumps, it will not stay higher than 7.99.  My Magnesium is perfect too at 1500. The only thing I haven't tested is the Strontium because I don't presently have a test kit for this and I've figured that if the Mg is good, my Sr probably is too.   Any ideas as what else I could do or am missing?  < you are right it is time for a calcium reactor until then drip as much Kalkwasser as possible all your evaporated water should be replaced with Kalk until your unit is done. after you install the reactor you will no longer have these problems with your calcium ph and alk. Are you sure you did not get a disease (RTN) from a new coral. do you quarantine new SPS corals if not you should begin doing that. Also do your have enough current going over the stony heads if current is light add a couple of power heads you will notice a big difference>  Thanks a bunch,  Greg N.  <hope this helps MikeH> 

- Carbon removing trace elements... - I have heard that if you use activated carbon in a filter, that it will remove trace elements.  True or false?? <True and false, it removes some trace elements, most notably iodine, but leaves plenty as well.> I use a Eheim Professional 2 canister filter, which uses a charcoal filter pad in it.  Would this be removing the trace elements I'm adding twice a week?? <Depends on what you're adding. I would only run carbon once a month for 3-4 days or when you notice any tinge of yellow in the water (best seen in a clean white bucket). Have fun! -Kevin> Pat Auburn, NY

Calcium, carbonate hardness, pH, and magnesium... i appreciate the help thus far. <Kevin here with you today> am going to try and make this as simple as possible. but i have 220g fish only with 220lbs of live rock and a wet/dry, plus a EuroReef cs12-1 skimmer. am fishless now (ich). but i always had a relatively low ph (7.8 - 8.0) and low calcium ( around 320) but a alkalinity (10-14). i understand the whole alk/calc relationship and am pretty knowledgeable with chemistry. my question is more about how to obtain stable conditions and types of products. i used a Kalkwasser type brand for a while. with a liquid buffer. added magnesium, iodine, and liquid aragonite and calcite calcium <what's that?> at the advice of the LFS. that was tedious so i changed to two part b-ionic for a while with not great results. <Since your calcium and carbonate hardness are already off balance, you'll need to add a straight calcium supplement (like calcium chloride)> i plan to have pretty heavy bio-load, not overstocked though. and i wish to keep my live rock looking great with coralline algae. but my main concern healthy fish, and additives with little margin for error. i plan on getting a ph monitor. <Good idea> and right now am thinking that i need to mainly add Kalkwasser daily, sometimes a buffer and hopefully nothing else with regular water changes. my problem is am not sure which type of Kalkwasser to use, brand, and method for applying. <The brand is insignificant, it's all the same stuff. Kalkwasser is good for your tank since it runs already runs a low pH. there is a lot of confusing info out there, especially with products and i just wish to keep it simple. do i just buy dry calcium hydroxide? add daily with top off? and buffer when needed? <Follow the directions on the bottle of Kalk, all your top-off water should be in the form of Kalkwasser.> no magnesium? <You'd need to test the level to see if it was low.> thanks i know its long but maybe the answer will be simple. <Good luck! -Kevin> thanks Brandon

Fusing Aragonite Sand Question 6/13/03 Hola all, <Hola> this is a question for Anthony if possible.   <all is possible in the Land of WetWebMedia... just audibly click your pharyngeal... errr, never mind. Howdy!> I have a DSB, 4-5" of REALLY fine aragonite ( pureAragonite.com ), almost like flour size.   <very good for DSB with NNR... my preference in fact> I had emailed last week about your slurry method and that I was having trouble raising my calcium.  My DKH is now around 9/10, and my calcium is around 330 or so.   <not bad at all... in fact, you can use just a little bit (temporary) of calcium chloride to get that Ca 350-400, then carry on with Kalk and keep the ALK 8-10dKH and it all sounds good to me. Recall to keep Mg levels about 3X Ca too> I have been adding about 1/2 teaspoon or so of Kalk using the slurry method in the morning.  The PH in the evening is about 8.19 to 8.2.  In the morning, I add the teaspoon of Kalk to get the PH to about 8.3? to 8.4 tops!   <all good> So to the question, I have sections of sand that seem fused together.   <the problem in this case is not that you added too much or too fast... but rather that the aquarium lacks adequate water flow to disperse the concentrated slurry. Seek 10-20X turnover for most reef aquaria proper. In the meantime, just ameliorate (add water) to your slurry and/or dose a little slower. This will prevent the local spike in chemistry and the clumping of aragonite sand> Little ones smaller than a dime to some bigger patches like the size of a quarter.  They are here and there throughout the bottom of the tank. A few, not a whole bunch.  They are flat and thin, really resembling a coin.  Pods and other critters seem to be hiding under them.   <heehee... cool> Is this actually fusing because of a calcium/alk reaction which I had read in another FAQ?  The PH doesn't seem to indicate there is a problem ( new pinpoint PH monitor ).   <agreed> Could some creatures be doing this?  Is it actually a problem? <yes... a bit dangerous/precarious. The slurry needs dispersed better for many reasons> Thanks for your time.  By the way, I ordered the new book about a week ago, nice that I still got the pre-order price even thought it was beyond the date shown on the site...so when is it coming!!!! Best wishes, Paul <very good to hear, mate :) The door on the pre-order pricing did finally close. The trucks are rolling next week to start to move the texts for fulfillment. Kind regards, Anthony>

Reef Chemistry out of sync 3/6/03 I am thinking that, the usage of calcification to form caco3, and increase co2(lesser cause) due to respiration in tank will leads to decrease in buffer capacity, meaning, decrease Hco3/co3 concentrations. And partly decrease Ca concentration. <in the biggest picture, yes... acidification from organic processed... nitric acid is formed, mineralization, etc> By Adding baking soda, NaHCO3 or alk or pH buffer in a imbalanced tank will lower pH because the CO3 is at low level, the added HCO3 ions are used up to calcification, and left with H+ and Na, the Na further Crowded up the already ion-filled water, the solubility of ions in the seawater is lowered due to increase ion concentrations. The left-over H+ will lower pH. Therefore further Ca ppt formed at the sand... a vicious circle. <over thought, but yes> That is why adding CaCl, or Mg additives (MgCl.6H2O) will not help, and will worsen the situation by overcrowding the water and create more precipitate. Is my theory right??? <correct with assumptions> This is a summary of what I said: 1: Water was balanced 2: Ca +CO3 use up from calcification and counter CO2 acidity, lead to lowered Ca and Alk capacity. 3: Coralline algae used up further Ca+CO3 and Mg <many things in your tank do> 4: Excessive use of CaCl, improper amount of Part additives and alk/pH buffer to maintain Ca and alk levels lead to crowded up water (excess Cl and Na) as a byproduct 5: the low solubility causes precipitation of Ca to form limestone from aragonite sand substrate. Further deplete Ca. <yes, but do consider that in aquaria with low-bio loads most all of this can easily be tempered with regular partial water changes (say weekly). Chemicals and additives are a slippery slope to navigate and they are not needed for most casual aquarists. Only for mature and heavily stocked tanks might you need to break out the Periodic Table of Elements> Since I added the baking soda, the pH drop and you said the system is out of balance, can I use the baking soda as a test to see if my system is in balance again after the water change?? <why bother trying to induce a negative reaction? Simply do weekly water changes... and test water quality to confirm "balance" and sync> Should I change the substrate?? <I see no need. Best regards, Anthony>

Re: The dinoflagellate fight Thanks, I will.  Do you need to regularly add magnesium or will this be provided through the reactor.   <depends on the demand by the system. Test and dose if necessary> Also won't the ph fall shortly after the Kalk dose is stopped.   <nope... they may be (and should be) unrelated to the extent that it would happen suddenly. You should maintain an adequate alkaline reserve to support pH. This is mostly unrelated to Kalk dosing (although Kalk indirectly supports ALK by tempering natural acids in the system). Still... they are two different things... buffer versus Ca. Keep your alkalinity strong and consistent and you can keep your pH anywhere you like it then> Also what other products were you thinking of besides Kalk. <I like Kalk best and alone for Ca supplementation. I use bicarb as buffer when necessary. I use iodine daily in small amounts for how fast it is taken from the system. And I rely on water changes for almost all else> Thanks for your responses.  I appreciate it.   <welcome indeed> It is hard to focus in on a reef when there is so much other geo-political going on , namely Iraq. <OK. Anthony>

Re: Kalkwasser Hello Mr. Fenner, This is the same person who you just answered regarding my mushroom only tank. You said I need to maintain my alkalinity and biomineral content. I understand what you mean by alkalinity but I do not understand what you mean by biomineral content and how would I do this? i.e. what type of product? thanks a lot- <The alkaline-earth elements Calcium, Magnesium, Strontium... Please read: http://www.wetwebmedia.com/Marind4of6.htm particularly the sections on marine water quality and associated FAQs files. Bob Fenner>

Specifics on ph-alk question Hello again Bob, Thanks for the reply to my original question concerning ph-dKH balance. You said to get back to you with specifics, so here goes. 180 gal. reef/ 3+inches live sand/150lbs.? live rock/40some asst. pieces coral/ 8 fish [largest are a yellow & purple tang]./asst.stars&snails,etc. Equipment-4 160 watt VHO bulbs powered by icecap ballasts/ photoperiod: actinics 11am-10pm/50-50s 12pm-9pm/Berlin skimmer w/Rio 2700pump/ U.S. aquar. wet-dry w/Iwaki pump-1300 gph return. I do a 45gal. water change every 3 weeks. I use R.O.-D.I. water for water changes/make-up water. As for additives, about all I add is Kent turbo calcium [1tsp. per day] to try and keep the Ca level up, and SeaBuffer as needed for alkalinity. I manage to keep the Ca level about 360. Every now and then I'll add iodine, strontium, or magnesium if the corals look as if they need something, but this is rare, as most of the time they look great. On any given day the ph will start out at 7.9-8.0 and rise to about 8.4-8.5, even though at times the alkalinity will drop to 4 or5. I would like to keep it up around 9 or 10, but as i said , as I add buffer it wants to push the ph up over 8.7. Nothing seems to be adversely affected, but it is really puzzling me. I really appreciate your taking your time to think this over and hopefully come with an an answer. Thanks a million, and keep up the great work. <Will try/endeavor to do so. What you have is a semi-classical case of "yo-yo'ing" of adding simple, soluble sources of alkaline and co-precipitating calcium (et al. alkaline earth elements/compounds... the Mg and Sr) additives... If you saw the energetics of the supplementing and the money being turned into white sediment "cement" in your system you might scream. Do consider either "going with" a simple two part (like B-ionic) alkalinity/biomineral treatment scheme BY ONE MAKER (wow, that's bright), or making the light year jump to a calcium reactor here. "IT" is your supplement practices that are (self)defeating you here. Please read over the Marine Alkalinity, Calcium et al. related sections on our site: www.WetWebMedia.com for more peoples anecdotes, explanation of what is going on here. Bob Fenner> Joe