Low pH and low alkalinity...is Coralife <salt> the culprit? 6/29/2011
Hi crew,
<Hello Jerry>
I have a pH problem in my 29 gallon FOWLR tank. The tank has a shallow aragonite bed, a Bak Pak protein skimmer, and an Aqua Clear power filter.
The only fish is a small firefish. The tank is kept covered, and I change at least 10% of the water weekly. The tank has been in operation for about 5 months.
The pH and alkalinity have always been a bit on the low side, but lately the pH is dropping enough to worry me. It's about 7.7 in the morning, and 7.8 in the evening. Recently I lost a fire shrimp, and even more worrisome is the apparent effect on small critters in the sand bed, rocks, tank walls, etc. I don't see any copepods at all now.
<Likely the pods were gobbled up.>
Other parameters: SG 1.023, Calcium 500, alkalinity 1.7 meq/l, magnesium 1350.
So the calcium is high and the alkalinity is low. Is there a connection, and if so, which is cause and which is effect? Does high calcium cause carbonates to precipitate out, lowering the alkalinity and allowing the pH to go down, which dissolves calcium from the aragonite and keeps the calcium up? Something like that seems to be the case, because adding Brightwell Alkalin 8.3 buffer hasn't had much effect on alkalinity or pH.
I've put enough buffer in to get the alkalinity up to at least 2.5 (according to the label), yet it hasn't made much difference. Something must be removing the carbonate salts I'm putting in.
<You have pretty much answered your own question. Yes, the calcium needs to come down to around 400ppm to reduce precipitation, and your dKH needs to go up near 2.5 meq/l. I would not dose any more calcium until this drops to 400ppm.>
I thought to bring things close to where they need to be with a big water change. But when I tested my WC water, the parameters were: pH = 7.9, alkalinity = 1.7, calcium too high to measure (above 520)! Not much better than what's in the tank now.
<Do you aerate your water used for water changes for 24 hours before adding the salt mix? Aerating will remove carbon dioxide, if present, which can lower pH levels.>
I use Coralife salt (with RO water). Should I conclude that my bucket of Coralife is worthless, and switch to another brand?
<Not necessary to do this.>
I have the feeling Reef Crystals is sort of the gold standard in salt, and according to http://aquariumwatertesting.com/AWT_...lysis_0208.pdf it has low calcium content. If I switch to Reef Crystals, could I get in trouble due to chemical incompatibility between the Coralife and the Reef Crystals?
I've heard that some salt brands don't mix with others.
<I don't believe Reef Crystals is the gold standard in salt mixes as well as the fact the some brands of salt do not mix with others. If the salt is properly formulated, it should not cause any problems when switching salts. If I were to improve on your salt mix, I'd go with Tropic Marin, Sybon, or the ESV four part mix. I am presently trying out the ESV product. It's a bit of a hassle to mix, but the parameters are always dead on and the water clears in a surprisingly short amount of time. The four parts include sodium chloride, magnesium, part A (liquid), and part B (liquid). Do read here for a better understanding of alkalinity and calcium.
http://www.wetwebmedia.com/calcalkmar.htm>
Thanks for any wisdom you can provide...
<You're welcome. James (Salty Dog)>
Jerry
Re Low pH and low alkalinity...is Coralife the culprit? 6/29/2011
James,
<Jerry>
Thanks for the reply. The only fish in the tank is a firefish, who doesn't seem to graze pods from solid surfaces...he only feeds from the water column. So I don't think he gobbled up the isopods.
<Mmm, just said "gobbled up", crabs, shrimp, etc.>
I have never dosed calcium. But the calcium content of my 1-day-old Coralife salt water is even higher than what's already in the tank, so I was looking for a salt mix that will give me calcium in that desirable 400 neighborhood.
<Have you referenced your test kit with another known to be accurate?
Seems rather high for not dosing calcium. May want to try a non-reef type salt where calcium is lower than reef type salts.>
I assume I need to modify what goes into the tank to get the calcium down and alkalinity up, as you say. Is there a way to break the feedback cycle of chemical reactions that doesn't involve ditching my batch of Coralife (given that I add no calcium)?
<I'd have your dealer check your calcium level to confirm your readings.
Your test kit could be dated and old reagents can give erroneous readings.
Some test kits require that you add
a given amount of RO or distilled water to the test sample. If you use tap water for this, any calcium present in the tap water is added to the test results which can give a higher reading.>
Yes, I aerate the water, but after adding the salt. You refer to aerating first. Is this an important distinction?
<Yes, you should aerate first to eliminate any carbon dioxide that may be present which will lower dKH levels in the new mix. Using the aeration feature found on
most powerheads will eliminate any CO2 if present in your mixing tank/tub.>
Finally, an experienced aquarist in my area told my problem is probably CO2, due to the cover on the tank. Is this a common phenomenon?
<Can be, CO2 is carbon dioxide, but the aeration in your skimmer should take care of this.>
Two months ago I propped the cover partially open at night, and the pH was a bit higher in the morning than usual, but not much.
<The pH generally is a bit lower during the night and increases during the day time hours. Have you read the article I linked you to?>
Thanks again!
<You're welcome. James (Salty Dog)>
Jerry
Re Low pH and low alkalinity...is Coralife the culprit? 7/2/2011
(Apologies for sending an email with no message a minute ago. Here's what I meant to send.)
<Not a problem.>
Hi guys,
<Jerry>
Following up on our exchange of low pH and alkalinity a few days ago, I've learned some things that may be of interest to you and your readers.
<OK.>
James questioned whether my calcium was really 500, given that I have never dosed this element. As suggested, I went to my LFS for some water tests.
They confirmed the high calcium...in fact they got a concentration that was higher still (over 600).
<Yikes.>
I tested the water I've been making with Coralife salt and found it had calcium well over 500. This has apparently also been found by others who tested Coralife salt. Don't know if that's typical, or if it's a matter of poor mixing in the bag I was using.
<A possibility.>
Anyway, lesson #1 is that you can indeed get very high calcium from your salt mix.
It turned out the low pH and alkalinity I was concerned about were spurious. The LFS found my alkalinity to be over 4 meq/l. The Red Sea test kit I was using didn't show anything like that. I bought a Salifert (titration type) test kit and confirmed the high alkalinity. So I was dosing buffer into the tank when I had no need to. I thought Red Sea test materials were good, but I won't trust their simple color-change kH test again.
<Titration would be more accurate.>
The pH also turned out to be fine. I was using a Milwaukee electronic (probe, not pen) type meter. This meter always showed pH below what the color-change test solutions showed, but I thought a carefully calibrated meter was more believable. But the test solution was telling the truth...my pH was 8.3, at least 0.3 more than the meter showed at that time.
<May just be seeing the accuracy range here. Some probes have an accuracy range of +/- 0.2. Your measured results are close enough for our purposes.>
I've bought several meters in recent years, pen as well as probe type, and gone through many bottles of calibration solutions, but have always found a significant discrepancy with pH test kits. Does this make any sense to you?
<Sure does, color comparator pH test kits can be difficult to read/match.
The best color comparator pH test kit I have ever used is the LaMotte kit.
No colored cards used here, each pH range has it's own color in a sealed vial. I believe they run around 60 bucks. Oh, and for those with deep wallets they produce the Oceanographic Test Kit consisting of several different test kits for 450.00.>
Thanks for the help...
<You're welcome, and thank you for the update. James (Salty Dog)>
Jerry

Re: Algae Scrubber Question... Coralife Salt f'   05/23/09
Dear Mr. Fenner,
<Eric>
Thanks again for the input. I think I found the root cause of my calcium levels. I've been using Coralife sea salt to make up my saltwater, and after reading some of the reviews of it on your site (negative overall) I decided to test the calcium etc in the saltwater. I made up a small quantity to the right salinity (1.026), and when I tested the calcium it was over 600ppm.
<Zow!>
This would explain why my levels are constantly high regardless of water changes etc. I'll change salts ASAP, and hopefully that will help. Just thought this would make a good additional warning for Coralife salt on your site (but hey the bucket came with a free T-shirt.... who can say no to that...ha!). Thanks again!
Eric
<Thank you. BobF>

Salt Mixes...Is Coralife "Bad?" - 04/19/07 Guys, <<Bruce>> Thanks for all the recent help with my skimmer. <<Quite welcome I'm sure>> I have another question regarding salt mixes. <<Okey-dokey>> I normally use Kent Salt Mix however, I ran out of that product and there was none available here in the market here in Hong Kong, so I looked around and ended up with Coralife Scientific Grade marine salt mix. <<Ok>> While going through your the site looking for reviews I came across one where someone said that they heard that Coralife salt is not recommended for a reef setup (which I have) but for fish only, and one of your crew agreed. <<Very likely...many opinions here>> I did not know how long ago the review was posted, forgot to look up the date and lost it. <<No matter>> So I am not sure if that review was in relationship the exact brand I bought or an earlier salt mix by Coralife that was not up to it. <<Likely what you bought>> My question is, was my choice a bad one? <<In what sense?  As in are there better salt mixes?...Yes, in my opinion there are.  Or as in will this salt mix destroy your reef?...No, I don't think it will.  But do make changes slowly/keep water changes small to start...just as you would/should do when changing to  any brand of salt mix.  The major issue with Coralife salt is the variation of major elements from batch to batch>> And if Kent Salt is no longer available here which other brand would you recommend. <<Tropic Marin, Seachem, and Instant Ocean are all fine products...and would be my choice above the Coralife product>> I know I may be pushing it with this question but I would be much obliged with a response. Regards, Bruce <<Not "pushing" at all...am happy to assist.  Eric Russell>> Coralife Sea Salt 7/9/04 Hi, I currently have a 80 gallon saltwater tank. I do have everything necessary to start mainly a soft coral tank of many easy to keep species. Except for the sea salt and the chemicals involved in order to keep the corals alive. <If you use a good quality sea salt and do regular water changes, you should only need to supplement calcium and alkalinity.  No other "chemicals" are necessary.  My heavily stocked 135g reef tank has been running for a couple of years with no additions except for calcium and alkalinity and 20% monthly water changes.  Some of the corals are growing so fast that they have become pests.> I currently am using the Coralife brand of sea salt.  I've asked many stores and they said that this is necessarily a bad salt to use for reef tanks. IS THIS TRUE? From what they say the salt is mainly for a fish only aquariums. <Coralife is not a brand that I personally would choose.  I trust the experience of others who have not been satisfied with it. Good quality salt is good for any marine aquarium use.  If you believe that a brand of salt is not good for reef tanks, you should not consider it suitable for any marine tank.> But, I was trying to figure out if I can use this current salt in conjunction with SEACHEM'S REEF COMPLETE reef additive. I'm not so sure if this product will have all the necessary additives and more needed to keep the corals alive. If not is there any other additive on the market that comes close to this or that would work well when I put both the Coralife salt and additive together. <Hmmm...  I think you are looking at this from the wrong angle.  We don't know exactly what is in any brand of salt, so we don't know what may be present in excess or what may be deficient.  The same is true for the additives.  So, how then are we to make a combination that produces a desirable (or even predictable) result?  The better approach is to use a brand of salt that you know has produced consistent and good results and use water changes to maintain levels of trace elements.  You will spend less money in the long run (those additives are expensive!) and have much better results.> Since any salt on the market does contain some elements: calcium, iodine, etc. in small or balanced amounts.  So, basically is there a additive that I can use to fully support my tank with corals in conjunction with the other elements and etc. found in the Coralife Sea Salt.  Thank you very much fellow aquarist..... <Maybe, but who knows?  Instant Ocean, ReefCrystals, Kent and Tropic Marin are examples of good quality salt mixes with long standing solid reputations.  Use one of those, do 20% monthly water changes and save the money you would have spent on additives for more important things like corals!  Best Regards.  Adam>

Trace of ammonia in newly mixed salt water Hello Bob, <Steven Pro in this evening.> I followed your advice and pre-mixed salt water in advance. Just to be sure I tested the premix water (1 week old) and it showed trace of ammonia (0.25). <Kind of strange> I then tested the tap water and it read zero. The salt brand I'm using is Coral Life. <Ugh!> Now I hesitate to use this premix because of the ammonia level. Please advice. <If this is fish only, I would probably go ahead and use it. But, if you have any inverts, I would purchase a different salt mix. Perhaps you could use this stuff to de-ice your driveway.> Thanks, Dung Ngo <You are welcome. -Steven Pro> 

A Grain of Salt? I really love and value this site, but the more I read, the more I shake my head and wonder. <Yep- sometimes I have to bang my head and fall over for a while! Scott F. with you today> I got my tank with the office I bought 1 1/2 yrs ago and love the steep learning curve. I have a 90gal, wet/dry with 1/3 the bio balls, AIS 90 skimmer, power compacts ( can't remember watts ), Ebo 500 watt heater, 20 gal sump, 2 - 401 power heads, carbon filter bags, live sand with about 75 LB LR( a guess ), 9 med size fish, many mushrooms and 1 small polyp coral.  I do 20-25% water changes every week (as you suggested, nitrates going down again ), RO water, ph 8.3, sg 26-28, nitrites 0, nitrates 20, alk 300, cal. 480, phos. .25. <Sounds like a good trend! Keep up the good work! I tend to recommend smaller (like 5% twice a week) water changes, but if your schedule is getting results- keep it up!> I'm wondering based on other guestions, does the salt vary by manufacturer? I'm using Coralife. <Well- yes- there are various subtle differences in formulations and quality control/consistency. Unfortunately, there are no "standards" within the industry governing the formulation or regulating minimum quality standards, so you have to go with a proven "winner". In my personal opinion (and not being an analytical chemist!), most of the reputable major brands (i.e; Instant Ocean, Coralife, Tropic Marin, etc) are quite good. I worry more about some of the "lower end" brands, in terms of quality control and packaging quality...Other than that- not too much to worry about, IMO.> If the skimmer should be first in line to receive water from the display, why do all the wet/dry and sump set ups I see for sale go to the skimmer second? <I asked myself that, too. Probably more convenient to make in this configuration...not to sure!> Should I change my set up to use a sump for the skimmer, direct from the display, that will overflow to my wet/dry and so on? <That, or a dedicated "level flow box" to serve as a skimmer compartment, where it receives a constant level flow of raw water right from the display> Also, all my rock is about 6-7 yrs old, is it effective/functional enough for now or this way too old? Thanks so much, ..........Mike <Hey- its probably thousands, if not millions of years old on the reefs...and it works there! I wouldn't be too concerned about long-term "viability" of live rock, as long as it has been maintained in conditions that foster its continued animal growth and condition. Hope this helps you! regards, Scott F> Mixing, matching synthetic salt mixes I have a 90 reef setup, I have read at many places that instant ocean salt is the best salt to use, I have been using Coralife, would I create problems if I switched brands? <No problems in making this change. No special mixing...> maybe my next water change could be half of each? <You can do this "all at once". Bob Fenner> Thank you in advance ....Kevin 

Instant Ocean vs. Coral Life I found this special on Instant Ocean salt at my LFS - $50 for 200 gallons. I normally use Coral Life salt ($50 per 150 gallons). In your opinion, is there a difference between the 2? <IMO/E Instant Ocean is a superior product, in composition and consistency> What can I expect if I were to change? <Higher, more stable pH, calcium... resultant incremental better health of livestock, ease of maintenance> What's the best salt you recommend? <Tropic Marin, and Tetra (!), if you live in Japan (only place sold). Bob Fenner> As always, Thanks, Craig