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FAQs on Marine Alkalinity Troubleshooting/Fixing 3

Related Articles: pH, Alkalinity, Marine Alkalinity, Understanding Calcium & Alkalinity,

Related FAQs: Troubleshooting/Fixing 1, Trouble/Fixing 2, Trouble/Fixing 4,

Related FAQs: Marine Alkalinity 1, Marine Alkalinity 2, Marine Alkalinity 3, Marine Alkalinity 4, Marine Alkalinity 5, Calcium and Alkalinity, Phosphate, & FAQs on Alkalinity: The Science of Alkalinity, Importance, Measure, Sources, Use of Additives/Buffers, Products by Name: & FAQs on pH: Importance, Science, pH Measure/Test Gear, pH Controllers & pH Buffers/Buffering, pH Anomalies (Troubleshooting/Fixing), & pH Products by Name, Manufacturer,


Kalkwasser no PH impact
Looking for your thoughts on this one. My tank PH has been dropping to around 7.6 at night.
<Mmm; poor buffering capacity... might drop some... like a tenth of a point, but not much more>

I wanted to try and boost my numbers a bit so I have been dripping Kalk on doser throughout the day to essentially compensate for the tank evaporation.
<Mmm; won't buffer, hold pH up...>

Been running it for 2 days now and the PH is still bottoming out at 7.6 at night with a high of 7.9 per day. Any thoughts as to why its not working?
<Oh yeah mate... time for you to try a mix of carbonate/s, bicarbonate/s. A plug here for SeaChem's products: https://www.seachem.com/marine-buffer.php
And do look up the different twixt pH and alkalinity.... BobF>
Re: Kalkwasser no PH impact

Thanks Bob. I actually have this on hand so can give it try.
<Ah, good. DO add to new, change out water and plan on changing, elevating BOTH pH and alkalinity slowly... no more than 0.1 pH point a week>
Right now the Alk level in my tank is 8.7DKH so I have some room to play around with. Is the marine buffer something that I will need to add constantly/daily or is it more of a monthly fix if the tank loses the
buffering capacity?
<IF your pH and/or buffering capacity is lacking, add a/the buffer every (weekly?) water change. AND do look at where you're lacking such... too olde substrate, live rock (can be added to, substituted), a lack of oxidative mechanisms (use of chemical filtrants, ozone, UV...), too much reductive mechanism addition (foods, feeding...). Bob Fenner>
Re: Kalkwasser no PH impact      4/14/20

Did some playing around with the system and the low Alk is definitely related to the cal reactor.
<... what's the pH of the material coming out of the reactor? This is a CO2 type?>
Just dosing 2 part ph is at 8.2. Because my tank is stocked I am dosing 250ml's per day and may even need to bump it up to 300. Is there any downfall to running a calcium reactor at a lower rate and then compensating the difference with 2 part to avoid dropping the PH in the tank.
<There is not; no disadvantage. Even Daniel Knop who sells his name to have reactors made uses such>
Seems a lot of people mix two part and Kalk but not two part and reactors.
<Welcome. BobF>
Re: Kalkwasser no PH impact      4/14/20

PH out of the reactor was 6.0 with an effluent of 130ml per minute.
<That's too low... I'd adjust the carbon dioxide downward till you have an effluent pH of about 6.8>
Unfortunately TLF's reborn media is no longer available and I had to switch to ARM.
<My ex wife used to distribute Knop Products in N. America... I've picked up literally tons of their fab media>
This is when all my problems started. Reborn melted at a higher PH's so I was able to maintain the same DKH of the effluent at 6.5 verses
6.0. The difference took my tank ph from 7.8 to 7.6.
<... Again, I'd be adjusting the CO2. B>
Re: Kalkwasser no PH impact      4/14/20

At 6.8 the media wouldn't melt sufficient to get any meaningful Alk in the effluent.
<Mmm; well; either have to switch out the media for something more soluble, or run much more flow through it>
When I tested it at 6.8 it was only 14. Reborn at 6.8 used to be 25. Maybe I got a bad batch of media?
<Am a fan of the friends, folks at CaribSea, but not their ARM product. I'd look around. B>
Re: Kalkwasser no PH impact      4/14/20

Thinking about giving SeaChem a try. Not a lot of reviews of the media but worth a try. Definitely a reputable company.
<A good choice, company. B>

I can't figure out what's wrong!   Gen. reef maint. and Alk. f's   1/22/19
I am writing to ask if you can think of something other than the normal tank parameters that might cause a new reef tank to not be quite right.
<Mmm; a bunch of possibilities>
I have a Fluval Peninsula AIO 13 gallon tank that is doing very very well, live sand, live rock, 2 small fish, lots of hermit crabs, snails, bristle worms and copepods. 2 peppermint shrimp and several happy corals. Pulsing Xenias, snowflake toadstool, yellow elegans toadstool, Zoas, colt coral and even a tiny frag of Montipora, and a tiny frag of Pocillopora, (both recommended beginner sps corals). All the corals are out and happy, growing and doing well. I do weekly water changes but don't add a lot of supplements
...just Seachem Plus. Per Sally Jo Headlee at GARF.
<Looks very nice indeed>
In the 13 gallon I have one Midas blenny, Lowly Worm. And 1 Firefish Incognito. You never see him except to eat. There is a crab of some sort in the live rock,....he never comes out so he must be a filter feeder or eats copepods. I don't know, but he's never hurting anything so I leave him alone He's not even eating my beautiful bristle worms! I have a wonderful group of them now. I like them a lot. Do you know they have faces with eyes!!
<Ah, yes; and facial palps!>
I got really close with my camera and actually was eye to eye with one,.... what a revelation. I thought they were like earthworms, but they are not!
Cute little faces really.
Per my API test kits,...this tank has 0 ammonia, 0 nitrites, 0 nitrates.
Calcium is high like 800 on the test, and the KH is high too. It took 16 drops to turn the test from blue to yellow.
<Do reduce these by serial dilution... and cutting back on supplementation>
Any way, this is my successful tank, and I love it. But the corals are growing and I'd like to move the
ones that will get bigger(the toadstools and the Colt coral) to my new tank
..............and herein lies the problem!
My new tank is a Innovative Marine 25 gallon Lagoon style tank. Short and square. I wanted more floor space and not a lot of height, I need to be able to work on my tank. Like the other tank, it's an AIO. Sump in the back, which works well for me, much easier to work on back there instead of on the floor! I used to have a big tank with a big sump. What a pain! .
In it has Live Sand, but instead of real ocean rock it has that Walt Smith brand man made rock (I was trying to do the "right" thing and save the reef!). It's done with the cycling and diatoms,....and it's nice and clear.
It's been about 2.5 months it's been running.
I have a little bit bigger pump than came with the Lagoon tank, because their pump was really bad and really noisy, so I put one of my backup pumps in. I have lot's of flow and my jets are aimed up to always ruffle the water we need lots of oxygen in the water after all. I do this in the little tank too. Both jets are aimed up.
<Should be fine>
So, my testing is showing the tank to be on the downward side of the Nitrate spike you get at the end of cycling,....it's between 20 and 10 ppm on the API Test Master Salt Testing kit. The Ammonia is 0, the Nitrite is 0 as would be expected. The KH is high, just like in the 13 gallon tank,....our well water is high in dissolved minerals. And although I haven't tested the Calcium I'm sure it's fine too since it's a new tank and nothing is using it up. The Walt Smith Rock is calcium carbonate.
<Yes; Walt and his wife Deb are friends, have been to their place in Fiji a few times>
It is my plan to add more live sand,....it's on it's way. I just read on your site that if you are going to have live sand, 3 inches deep is better than 1 or 2 for the nitrate bacteria.
<This is so; the deeper the better; IF not deep, then finer grade>
I have added my cleanup crew, hermit crabs (reef safe ones) and a variety of snails. I have added copepods. I have some of Sally Jo's Garf Grunge mixed into the sand bed too. I also seeded some of the 13 gallon tank's sand into the new tank. So, I do have copepods, but no where near the thriving community of them I see in the 13 gallon tank which is just crawling with creatures. This tank has a few of the larger copepods walking on the rock now and then,....a few of the little ones that look like shrimpies with big white eyes. Mostly though I see things zooming around in the water, against the black back of the tank,....millions of them. They aren't floating, they all have different trajectories, so I know they are alive. But there is almost nothing inhabiting the rock,...I don't think they like that Walt Smith rock,....but it's too late now to take it out. I don't want to kill the ones that are living in it.
<This takes time. I would move a good deal of the substrate from the 13 to the 25>
The one thing that both tanks have in common is the PH. It is always between 7.8 and 8. It doesn't go up to 8.2 or 8.4. The only supplement I use is Seachem Reef Plus,....Sally Jo said I need to use that 2 times a week.
Otherwise, I only feed New Life Spectrum Thera A pellets, no frozen thawed food at this time. Lowly Worm and the Firefish are happy with the pellets and so are the other creatures.
Ok, so the problem is this,.....Despite the water parameters being ok,...not perfect,....but getting there.....why won't my little pieces of corals open up?
<Mmm; could be a few things... from the too-low pH, a lack of useful food/s, to a deficiency in "something"... like iodide/ate, iron....>
I have a tiny piece of colt coral, a small cutting of my big gorgonian coral,...and some button polyps from Sally Jo. Only the Button's are open all the way, the colt coral is all scrunched down in his barnacle, and the Gorgonian won't open his polyps. He's just laying there with them poking out but not open. All three of these are fully open and growing like weeds in the 13 gallon tank. I'm so frustrated. I thought that softies like some nitrate in their water for food? Am I wrong?
<All in balance; but yes, some NO3, HPO4....>
I can't buy any fish for this tank until I know that things are balanced and thriving! I don't want them to suffer and die. Can you help me figure out what I still need to correct?
<For now I'd experiment with adding just one thing at a time... DO try some fine frozen food/s (or a blended product), OR iodide-ate (SeaChem's line is a fave), OR Fe...>
I've done many small and 1 large water change, to bring the nitrates down,..
..I will of course continue doing so. But I can't figure out what I've done wrong in this new tank. I will take a couple pictures for you,....maybe you can think of something I haven't. Thank you. Pictures below.
First the 13 gallon tank that's doing well. It is right next to a window, has plants behind it, but still get tons of real sunlight. I think that's partly why it does so well. And I don't scrape the back wall, the snails need something green to eat, there's no algae in the tank any where. Plus the algae filters the light coming in a little.
<Yes; I'd leave this be>
The 3 month old Lagoon tank...looks like mars or some place uninhabited! I hate that look. I hate that Walt Smith rock too. It's ugly. But it's better for the environment I hope. The new tank has a fancier light,....better for corals it said. It's a Current light. With the fancy interface, but I don't use that part really. The one thing I don't have in this tank is pumps,.. there is so much flow I didn't think I needed more. I have them if I need them though. .
Thank you for taking the time to even read this massive post,....I hope the pictures aren't too huge.
<They're fine; thank you>
Amanda Wilson in Jackson, NJ, USA
<Do please keep me/us informed as time goes by with what you're trying, the apparent results.
Bob Fenner, San Diego, CA, USA>

13 gal.

25 gal.

Re: I can't figure out what's wrong!       1/23/19
Thank you Bob for you fast reply! You always amaze me.
<Welcome Mandy>
About the calcium and hardness, I don't ad any calcium to my water,...I'm not sure why it's so high, maybe it's just my well water. I guess I should test it.
<Please do... the SeaChem product likely adds... Do you have, make reverse osmosis for your drinking, cooking? I'd cut the well water with this if so>
And since it doesn't seem to be a problem in the 13 gallon tank I hate to start to do serial dilution of anything. I will only upset the whole thing!
The corals seem quite happy there and so do the fish and other creatures.
<Real good; I do agree>
About taking half the substrate from the 13 gallon tank and seeding it into the 25 gallon, I can do that....I have new sand coming and it can replace
what I will remove,....but it will stir up what Sally Jo calls a "Sewer" in my 13 gallon tank!
<Ahh, good>
All the stuff suspended in the substrate will be in the water after I do that. Won't that cause the 13 gallon to have a huge nitrate spike and kill all my creatures? Perhaps I don't understand this well, please elaborate?
<Use a siphon hose, and pour off the supernatant... the floating water and debris>
I have considered taking half of the live rock in that tank, (chisel it into two pieces) and move one side to the new tank, but at this point the Xenias on that live rock will all die in the new tank, the last little group
I put in scrunched down and just disappeared! It was so sad. I don't feel I can do that to them even though I have lots of extras. They are my favorite coral of all. Sorry. I know many people don't like them, people consider them to be weeds, but I love Dandelions best too. I'm a nut.
<Then we are nuts>
So, about the Iodide, I have the Seachem Iodide already, I lost my one and only cleaner shrimp when he was molting a few months ago, so I thought I might need more Iodide. I only used it once though, because then on your site it said do not add things you don't test for, and I don't have an iodide test kit. (I will get one though.)
<Do use this>
Why would I add Iodide to a new tank with new saltwater mixed up,....I use Instant Ocean Reef Crystals I assumed that the salt has the correct amount of Iodide in the mix?
<It "drops out of solution" very easily>
But if you think that might be what's missing, I can add it. I'm not sure about Iron,...it's in the Reef Plus I believe. So is iodine....but it's very small amounts. Maybe I need more? Once again, I though that salt mix would have all these things in the proper amounts,... and I've been doing water changes too,....lot's of fresh saltwater.
<Try just one change at a time... Good science!>
You know, there is one thing that was different in the new tank than the older one,.....I started it with a different salt mix. Red Sea Coral Pro Salt. It had great reviews and I thought it might be a step up from the Reef Crystals, I wanted to try a SPS coral,....but when I told Sally Jo she said NO. Go back to the Reef Crystals, and I have for the last few water changes.
I don't know if that might be part of the problem. The RED SEA Coral Pro salt is much heavier they say in Magnesium, Calcium and Carbonates and some other coral building stuff than regular salt mixes.
From their label on the can of salt:
"Coral Pro Salt Mix provides the biologically balanced, elevated levels of the foundation elements (Calcium, Magnesium & Carbonates) necessary for sustainable, accelerated growth and enhanced vitality of all corals."
Maybe this Red Sea Salt mix is why my calcium and my hardness are so high?
<Could well be a contributor>
I didn't really use test kits when I started the first tank,....so I didn't test it until after I used the Red Sea salt,....and both tanks are the same.
Even the old tank got some new water made with the Red Sea Coral Pro salt.
Maybe thing just aren't balanced because of it?
<Again; a possibility>
About adding food, I do, I feed the hermits and snails a few pellets everyday, don't want them to starve in such a naked tank. There's nothing left to eat in there since they ate all the diatoms.
<A fine small food, like Cyclops (-eeze) would be my first choice to add here>
Ok, I'm sorry I think I have too many questions!
<No worries. BobF>
Re: I can't figure out what's wrong!       1/23/19

Ok! I didn't think about using a siphon! But when I pour off the dirty water won't I lose copepods and bacteria too?
<Not much of them, no. For bigger animals (like crustaceans), pour the water through a net>
Isn't that why you want me to move the sand to begin with? To move copepods and bacteria? I could use a fine net for the bigger creatures I guess.
<Ah yes and yes>
OK. I'll do that. It's Oolite sand, that's my favorite. Even if it does get stirred up easily. It's still the prettiest and softest sand. Then there is a little crushed coral on top.
Then after I get the sand back into the newer tank, I can add 1 dose of Iodide.
Perhaps that will help.
<Am hoping so>
One thing though that I still don't understand is why do I have such a hard time keeping the PH up.
<Mmm; it's likely a good deal due to your high Calcium level... there's a negative interaction twixt high alkaline earth (Ca, Mg...) content and pH>
It's very stable,....it's stays at 7.8 all the time on my tests.....maybe too many people breathing in the house?
<I hope not... though too-sealed homes can have such an effect>
I've read that any where from 7.6-8.4 is ok,....but only for fish. Corals and inverts need 8 and above. I've added baking soda,....several times, it never stays up.
The other tank is at Ph 8. Not high enough really either,....but again, everything is thriving. I just don't get it! I think it must be the liverock is just a much better Rock.
<Likely is the rock>
It's real ocean rock,....and millions of thing live inside it, I see them crawling around when I use my camera and get really close, there are thing in there that are just amazing! Long whiskers and funny curly bodies,... things that walk upside down and then flip over and never miss a beat!
I love watching them. My favorites though are the ones that look like tiny shrimp and have big white eyes....they are so fast! They love the barnacles best.
Bob, there is nothing in my life more wonderful than that 13 gallon tank.
It s like looking at heaven. I really want the 25 to be just as happy.
<In time... B>
Re: I can't figure out what's wrong!       1/23/19
Thanks so much Bob, I will give it more time and do the things you suggested
<Thank you Mandy. B>
Re: I can't figure out what's wrong!       1/23/19

I tested my well water, straight from the tap, not through the Pure filter.
It only took 2 drops for the color to change on the Calcium. Very low.
And it only took 3 drops for the KH to change! So, we don't even have a lot of minerals in our well water.
<Not ones involved in hardness at least>
We do live in the Pine Barrens in NJ. The soil is very sandy and acidic I believe. Lot's of mountain laurels and pines.
<Have been to a few places in New Jersey; many small water districts in the Garden State, and the ones I'm familiar with do have good/great water for human use... not much dissolved solids>
There is a little Phosphate,....it showed .5 ppm's.
<Likely fine for your set-up/s>
The PH of the tap water was the lightest yellow (lowest reading),...7.4. Of course, it doesn't measure lower than that on the test, so who knows it might be even lower.
<Mmm; yes...>
I have drinking water test strips, I will check it with them too,....can always use a second data point.
Ok, on the drinking water test strip it was again at the lowest color, which says reads ph 6. So, I guess our water is somewhat acidic. I wonder why the test strip doesn't go lower than ph of 6?
<Just what the kit is made for. There are lower colorimetric assays for pH et al. I taught H.S. chemistry and physics>
I wonder how that affects my water in my salt tanks?
<Yes; this water's "hydrogen ion content" will eat away at the alkalinity, reserve in your mix, and that of the substrates (rock, gravel/sand) in the tank itself. You might... should look into increasing the amount of baking soda, or using (better) a pH bolstering product. Again, another SeaChem product is my choice... This should be mixed into the change out water ahead of use, all allowed to sit a few days... if you can, a week ahead of its use next maintenance interval>
So, it must not be my water that is sending the Calcium and hardness up so high. I must have been the Red Sea Coral Pro salt mix.
Or maybe the Walt Smith rock gives off a lot of minerals in the beginning?
<Indeed it can. It is touted as being "ocean cured" after being made (on shore)... but the cement part is quite alkaline for a while>
They do say to let it cure until the PH gets up to 8 or higher in the fine print online.
Is that what's happening? I thought because there is no ammonia or nitrite it was all cured?
<Could be>
Do you even have to cure dry rock?
<Not for the same reasons as live, but yes; it does need to soak... to remove excess materials that are easily soluble>
It's never even been in the ocean,...why would you have to cure it at all?
<If it's the product I've met with... made in Fiji; then it has been cured... again, by being placed underwater on the shallow reefs for months>
The sand is just regular CaribSea brand. I don't think it's the sand releasing the calcium,....or minerals,.....or is it?
<Also a potential factor>
I just had a light bulb come on in my head! IF the water comes in slightly acidic....does that do what vinegar would do if you dosed the tank with vinegar?
<Indeed; yes. All acids are proton donors, electron acceptors>
I've read that people do that to release more calcium and minerals from their rock and substrate. Maybe it's just happening naturally in my tanks because of the water being at PH of 6.
<Well; actually all this is a mix... IF you add equal numbers of Hydrogen ions (acid) and Hydroxyl ions (base), you end up with a neutral pH solution: 7.0... >
When I had large reef tanks, 150 gallon and 50 gallon, they were all fine too with this local well water....something's different in this new tank.
And the only think that's different is the Walt Smith Rock.
<You could soak or to save time, boil a piece in tapwater, measure the water pH after....>
This is weird.
<Mmm, just unknown for now. BobF>
Re: I can't figure out what's wrong!       1/23/19

So, I guess that reading isn't too weird,...for the pH in the tap water.
I read this that says that a pH of 6-8.5 is normal in underground water.
Like well water.
https://www.water-research.net/indexphp/water-treatment/tools/the-ph-of-water  In general, a water with a pH < 7 is considered acidic and with a pH > 7 is considered basic. The normal range for pH in surface water systems is 6.5 to 8.5 and for groundwater systems 6 to 8.5. Alkalinity is a measure of the capacity of the water to resists a change in pH that would tend to make the water more acidic.
<Ah yes. B>

Re: I can't figure out what's wrong!      1/24/19
Bob, the Walt Smith rock I got is not the one they put in the ocean. I spoke to them on their FB Page and he said I bought the one that is never in the ocean.
<I see; like their 2.0 product... quite alkaline>
They also make one that is put in to the ocean,....but Liveaquaria doesn't offer it on their website, so I never knew about it.
I wish I had. It wasn't cheap and I believed it had been put in the Ocean because I watched their video where it shows it being in the ocean for a while then shipped out.
But that was the 2.0? Or 2.1? I don't know. Either way, I ended up with just dry rock.
<The test I mentioned. B>
Re: I can't figure out what's wrong!      1/24/19

I just checked the Reef Buffer online and it says it raises Alkalinity a lot too,....will that be ok in my tank?
<Ah yes>
I already am off the chart on alkalinity. It took 16 drops to get the color change.
Maybe baking soda is better for my situation?
<Try it and see. The carbonate in commercial products is "stronger" and  more persistent than bicarbonate... BobF>

180G mixed reef with sudden low pH issues, pls help!         8/3/15
Hello! Long time listener, first time caller. I have a problem that I can't seem to find the answer to and its starting to have an effect on my aquatic charges as well as my psychological well-being. My setup is a 180g mixed reef (fish, LPS, SPS, softies). I use an Vortec MP40 and a MaxiJet 400 to supplement the circulation that comes from my Reeflo Hammerhead.
For lighting I have 3x Chinese Black Boxes. I use a protein skimmer, a Phosban reactor and NPX biopellets to control waste
<Mmm; these chemical media do have downsides>
and, occasionally, a filter sock.
<Needs to be cleaned/switched out; daily>
My problem is my pH.
<More likely alkalinity, alkaline reserve eh?>

I have an Aquacontroller that have used for several years to provide constant, real-time pH and temp readings. It has been a great way to quickly assess the goings-on in my tank between testing. Recently it required a cal and afterwards the pH was much lower than I expected. At first I suspected a bad cal, but a second electronic meter as well as the
API drop test (and a THIRD lab grade electronic meter) corroborated the result. Here is a 'snapshot' of my parameters after my photoperiod:


<This is low.... I'd keep 8.2 at a min.>


I'm sure a pH of 7.85 by itself doesn't spell immediate disaster, but at night I am dipping much lower, like 7.65 just before the lights come on. As a way of "QC'ing" my probes I mixed a new batch of Red Sea Coral Pro sea salt @ 1.025 SG and boom, 8.2 pH. Both my total and carbonate hardness test kits read in the 12 dKH range. I was running a CO2 reactor, a habit I
have suspended until I get my pH squared away again.

I tried mixing 2 tsp of Kalk in 1 gallon of RO/DI water and dripping it all in at night, to very little effect. I'm getting a white haze on my glass, so I'm thinking I am hitting saturation for my nocturnal pH.
<Mmm; yes. I would NOT use Kalk here>

My corals look stressed and I've started to lose some of my SPS (1 bleached, lost tissue, died, 2 bleached but are... recovering?, 2 sloughed off ALL tissue overnight). Most other LPS/softies/inverts/fish look and act fine but I'm getting very little growth/polyp extension.
<Water changes for now.... and using (for the short term) a commercial product that is heavy on the carbonate side. See SeaChem's line here>
Apart from RO/DI & Red Sea Coral Pro salt 15% water changes, I've tried adding baking soda,
<Mmm, bicarb. won't raise the pH here past where it is>

Kalk, 2-part, and aerating the tank with outside air (my sump is in my garage with an open window, but I've also run my skimmer intake outside as well). Interestingly my last 20g water change with 8.2 pH water seemed to drive my pH down about 0.1... I don't want to add anything more because, simply put, I don't think my water can hold it.
My tank in its current manifestation is about 2 years old but some of the live rock and sand is as old as 10. I've changed some pieces of rock and some sand out periodically, but I'm sure some of the old stuff is still in there.
<I'd switch out more>
I was using crushed aragonite
<And use crushed coral>

at about 2-3 inches, but I switched the right half of my tank to a finer grain size when I re-re-homed a friends corkscrew long tentacle anemone.
I'm wondering now if the particle size on the remaining aragonite on the left side is too large and harboring too much funk.
<Could be a factor>
It isn't visibly dirty, but I'm sure if I stirred it up there would be a reckoning...
Do you have any ideas regarding my pH situation?
<Oh yes; all sorts. If it were me/mine, I'd do the above AND be reading re RedOx measure.... I'll bet yours is bunk low
I can't imagine a 7.6 pH is conducive to coral growth and development, and the sudden onset of the situation accompanied by my loss of coral has me in a panic. The situation only seems to be worsening and I'm not sure what to try next.
Matt, St. Pete, FL
<Consider the changes mentioned and the addition of an ozonizer. Bob Fenner>
Re: 180G mixed reef with sudden low pH issues, pls help!

Thank you so much for the ideas, I think I will remove the crushed coral (not aragonite, sorry) sand I have and replace with 2-3" fine grain,
clean the live rock, then do a significant water change (50%?).
<Okay; with pre-mixed>
I've ordered an ORP module from Amazon, but finding an ozone generator has been a challenge.
<Oh; they're about. Try Dr.s Foster and Smith>
I only use my filter sock intermittently, 1 day at a time so that shouldn't be too much of a problem. I just use it during cleaning and water changes to catch what I kick up.
With respect to the Seachem product, would you recommend the Reef Carbonate
<This one>

or Reef Complete, or the Marine Buffer, or some balanced addition of multiple products? I ask because I am reluctant to ever just add one side of the equation and I didn't quite follow that piece of your advice. Should I be aiming for a higher KH
<Mmm; not higher, but a mix of agents that will trend to keep the pH higher>

or ‎did you mean for me to just try a different supplement for now?
<Going forward; we need to find out what the real source/s of lowering pH are at work here and solve them. I'd pull the Carbon pellets and Phos remover for now as well>
What goal should I have in mind, I guess is what I mean.
<.... a pH twixt 8.2-8.4... >
Also, I try and use the Phosban and NPX sparsely, but would you recommend I discontinue their use?
<Yes; these products may well be nicking your ORP to nada, dropping not just pH, but the systems capacity to support life en toto>

Thanks again,
<Welcome. Bob Fenner>

Reef Tank dosing issue     10/8/14
Hello crew it has been some time since I wrote last but I need some help because I find myself scratching my head and running in circles... A little history of my reef tank and what it contains, ( this will be long) it is a 75 gallon reef with thirty gallon sump, reef octopus skimmer, uv sterilizer, carbon reactor, gfo reactor, ATO system, reef breeders photon leds, main return pump is a Mag drive 9.5, and I also have Hydor power head in the tank 1150 gph , I have a very very large hammer coral with 100 plus heads, softball size Pectinia, large Acan colony, large brain coral, several sea fans, two large Stylophora, one large Pocillopora, one large millepora, and a 5 inch derasa clam, shame on me but I have never really tested my systems but I never really needed to, I did my weekly water changes with high quality salt and never had issues for over seven years, however my eyes started telling me something was off, coralline algae was bleaching and died off, my clam was beginning to gape and growth disappeared, and corals lost there vibrant colors, no losses thank god. I ordered new Red Sea foundation test kits, my initial parameters were calcium 300, alk 7.6 and Mag of 1180. I spent literally days reading and attempting to understand the mg/ca/alk balance and think I have a decent understanding of it after relearning chemistry. I made the decision it was best to raise each parameter individually in small amounts and then begin a two part dosing system. This is the part I can't figure out, I raised my Mag to 1360, my calcium to 420 and they are holding steady with no changes, but my alk will rise to 8.1 after one dose but drop back to 7.6 with in 24-36 hrs , I am hesitant to raise it any more at one time.
<The Calcium is precipitating the difference out>
I was dosing every other day to raise it and then once I reached the desired levels I was going to switch to the two part to keep it there.
<I would switch; go w/ the two part now>
There has been no precipitation that I have seen, the corals and clam do look much better and the clam is no longer gaping and has new growth however no new coralline algae that I have seen. Is it possible my tank is using this much that fast?
I have been at this for three weeks and I have no clue how to raise the alk up to the 9 area
<Don't obsess re... allow the [Ca] to drop to about 380 ppm, and all will be well>

and keep it there so I can start dosing the two part daily, how would you suggest I go about this issue? Can I raise the alk to 8.1 and dose the 2 part at the same time and continue raising the alk every offer day until I get to my target of 9.5 alk?
<Best to not try doing both simultaneously. One approach OR the other>
Thanks again
<Welcome. Bob "Stoichiometry" Fenner>

DKH, up and down!    7/14/13
Hi crew! I have another chemistry question for you all!
My water parameters have been fairly stable for 2 months in my new 75 gallon reef tank.
 a.. Mag 1400
 b.. Cal  440
 c.. pH 8.3
 d.. Sa  1.023
Except for the DkH. It drops from 8  to 6 in a weeks time.
So  I dose with Kent's Supper Buffer DkH to bring it back up to 8.
<I'd switch to SeaChem's products. Better value>
I have a very low bio load with 2 brittle stars, 3 Mexican Turbos and 3 Chestnut Turbo snails, 2 Chromis, one small carpet anemone and 2 tiny peppermint shrimp.
I run a Remora skimmer
hob filter w/Chemipure elite
and a refugium with Chaeto and Miracle Mud.
<Mmm, this last... increasing reductive "behavior" in your system likely>
I use RO/DI water only, top off every 5 days and change 15 gallons every week.
So, what am I doing wrong?
<Mmm, nothing>
Thank you for helping me achieve my dream tank! This will be my third attempt!
<I'd keep using a source (commercial) of carbonate, bicarbonate... added to your weekly water change out water... and not be concerned. Would leave in the Mud, would switch to SeaChem... Bob Fenner>
Re: Dkh, up and down!    7/15/13

Bob,... not sure what you mean by "reductive behavior" .
<Mmm, as in reduction/oxidation.... "Acidic"... all captive systems tend/trend toward acidity... the alkalinity being "eaten up" with time...
Does this make sense? The net processes in our systems "run down" the pH... hence the need to have countervailing strategies... alkaline material (rock, substrate), water changes...>
Do you mean that Chaetomorpha AND Miracle Mud in the refugium is causing the fluctuating dKH?
<Mainly the mud.... the organic component; yes>
<Welcome. BobF>!
Re: Dkh, up and down!     7/16/13
Ok Bob, that does explain the process, but still not entirely sure what to do.
Below, you said to "leave in the Mud" but if the mud is contributing to the "reductive behavior" why have the mud at all?
<For all the good/things it does>
 Or, for that matter, why have a refugium?
<... "see WWM re">
 Does this system NOT contribute to oxidation?
<Yes; both reaction series>
Wow, look what I just found!
http://www.wetwebmedia.com/redox.htm Going to read this now!
<Heeeeee! A panoplia of bland statements on a quite esoteric, but VERY important topic>
Please bare with me Bob, I do NOT have a PhD,.........yet!
<Me neither. B>
Re: Dkh, up and down!     7/16/13


Alkalinity Too High... too much added to a one month old sys.      6/10/13
I have a 110 gal FOWLR tank, (I used to have some corals and sold them from a previous 42 gal and a small lettuce coral got left behind and is in my new tank)
I believe this happened to me.  
Buffers alone are not generally a good method as they raise pH little, and result in excessive alkalinity. Unfortunately, the labels on many commercial buffers are written in ways that convince aquarists that the pH will be fine if they just add some buffer. More often than not, the pH is not improved for more than a day, and the alkalinity rises beyond desired limits.
<Can; yes... And I'd emphasize/state that this is not the case w/ all buffer/ing products. Some manufacturers are more "completely honest". A fave: SeaChem>

My PH is at a desired level now but my alkalinity is too high now.  My calcium was a bit too low so I added 2 caps of Purple tech. 
<... not a fan of this (or many) Kent products>
I was going to test the calcium tomorrow and see where it stood. I   I was just going to leave the tank alone to settle down once the calcium is right.  All my other water parameters are good
Am I on the right track or is there anything I should do about the alkalinity now?
<... Depends... on what the alkalinity is due to... carbonates, bicarbonates... When, where in doubt, best to do either a massive (pre-made) or successive water change/s... to dilute the "Dead Sea effect" of having added (so many, much) products>
 My tank is a little over a month old
<?! You shouldn't have to be adding anything here>

 and my first water change/maintenance is scheduled for 1st part of July. I can ask for it sooner if necessary. I cant lift the canopy off myself so I have to have someone do it.
<Mmm, do look about re gear that can help you w/ automating lifting this top... there are hinged arrangements, even infra-red signaled motorized lifters!>
Thanks so much.
Barbara Wilhite
<A pleasure to share, help. Bob Fenner>

Alkalinity 5/10/13
Hi Crew,
<Hello Adam>
Just wanted to double check with you as I have read it should not be a problem. I run a FOWLR system and I recently started testing for Alkalinity and it was off the scale of over 17dKH. All my fish are fantastic, even delicate species like Yellow Cubicus boxfish/Blueface angel etc and I think this is due to an overdose with Seachem Marine Buffer. Unless you recommend something different I am going to leave the system for the natural biological cycles to bring down the alkalinity and use smaller doses next time.
<No danger and I would let it take it's course, regular water changes will help lower the dKH.  Do not add any buffers during this period. James (Salty Dog)>
Regards, Adam.

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