Zero Alkalinity

[eroc23]

Hello all,

New to the reef experience, but I've been keeping Cichlids for years. This site has been invaluable for learning about reef keeping, so I thought I'd reach out for help.

I'm trying out a nano-reef (14 gallon) and I'm having difficulty that google and the LFS can't seem to solve. Sorry for the length, want make sure I am thourough in my description. So here it is:

I have a 14 gallon nano reef. Substrate is 90% live sand, 10% aragonite. I made my own life rock according to GARF (aragocrete). I let the rocks sit underwater for 6 weeks in a cooler. I then removed them and let them dry. I then put them in the tank and let them sit there for 2 weeks. I changed the water.

I thought at this point, was ready to cycle. So I let it sit there with a light cycle of 12 on /12 off. Started to get this bright green neon algae on the rocks (Not the hairy kind). No big deal, future cleanup crew needs to eat anyway. Testing my water parameters, everything looks perfect except:

Alkalinity is always at zero. No matter how much I put buffer in there, within 24 hours, it's back to zero. Here are the parameters of the water I put in the tank:

Ph: 7.8
Alk - 1.7
Calc - 940 ppm (yes, it's that high, my LFS didn't believe me until he tested it himself)
Phos - 0.05 ppm

Now...the parameters of the tank currently

Ph. 8.2
Kh - 0
Calc - 940
Phos - 0.05 ppm
Temperature - 81.4 degrees
Salinity - 1.025

I used a kH buffer solution for 14 gallons. 24 hours later. Back to zero.

I used for 40 gallons in one shot. 24 hours later, back to zero.

Getting a little frustrated here, I used for 800 gallons in one shot. 24 hours later, back to zero.

What in the world can be so potent that drops my Alkalinity like that? I've used this same water in my Cichlid tanks for years with no issues what-so-ever.

 

[miked0523]

Your water is way out of balance. calcium should be about 400. At this point I would do a 50% water change wait a few days check, Then keep doing water changes until your water is balanced, Stay away from the buffer. maybe your homemade rock is doing something?

 

[imcosmokramer]

yeah, something is not right. Do the WC and test again.



My SPS Tank
My Anemone Tank

 

[Frick-n-Frags]

also, maybe get a second opinion. what if your reagants are bad or something.

Bory time (boring story )
waaay back when, before i knew about salifert, i had a seatest and a redsea alk test. so i'm reading 3.5 just like i'm supposed to and my sps bleached. my montis all turned a different, lighter, designer color, ie the orange tipped brown went to whit tipped orange etc..dark green went to pretty yellow-green....THEN it all bleached. i was clueless and eventually, Erik tested my water with his salifert. 1.3 was my alk. I had two bogus test kits. i got faked out but good on that deal. point being: it can happen....

 

[Chris27]

Just a suggestion, but given that it's only a 14Gal, and theoretically no livestock, I would perform a 100% water change with a new bag of salt mix and some fresh DI water. Thoroughly test the water before you put it in the tank to ensure that Alk and Calcium are in check. Wait another 24hrs, then test the tank water again.

 

[reeftivo]

I've read that high silicates can precipitate carbonate out of solution.

The Aragocrete may or may not be contributing.

May want to check silicates.

Just a thought!

 

[lordofthereef]

Sounds to me you just have a bad set of kits. Did you get them all in a package?

 

[eroc23]

Thank you everyone for your replies.

As far as the theory of bad tests, I don't think so. I use two Alkalinity tests.

Red Sea and Aquarium Pharmaceuticals. Both of them show the same results. I even tested right after I buffered, and it showed positive alkalinity.

The Calcium I just used the AP brand.

The Calcium was verified by the LFS doing another test (not sure brand).

See....I'm thinking the concrete might have something to do with it, but I've put this stuff in my Cichlid tanks, and it works great there too. There is something definitely amiss here.

I'm going to flush the tank completely and see what happens. I'll post on here again with the results.

 

[sjames]

what do you get when you test your water change water for alkalinity?

Im guessing your alk is off the charts, im not familiar with the test kits your using, but im guessing you dont ever see a color change and your determining that means 0 alk?

Is your sand bed clumpy or even solid at this point?

 

[eroc23]

what do you get when you test your water change water for alkalinity?

Im guessing your alk is off the charts, im not familiar with the test kits your using, but im guessing you dont ever see a color change and your determining that means 0 alk?

Is your sand bed clumpy or even solid at this point?

The alk in the water change is 1.7 (low), so there is initial amounts of it. Basically, the color I see is a very light yellow, which indicates zero.

The other test for carobnate hardness shows 3% dKH or 53.7 ppm (pretty close to zero)

When I put the buffer in, I do a test and see the water does indeed change to blue, varifying that the test works (at least in part).

Is there a certain 'brand' of tests that is accepted as the best or most reliable?

 

[sjames]

Ive used both the salifert and elos alk kits, they have both been accurate for me at least.

The problem with your disappearing alk, is if it is indeed going down that fast, you should have visible evidence of that, solid sand-bed, pumps seizing up, white/brown dust coating everything.

As for your rock, cement products are very alkaline, and will normally drive up pH and alkalinity, but your pH is low, so I assume the period that you cured the cement was sufficient, so I'm not sure if that is a factor or not.

 

[eroc23]

Funny that you should mention it, after I added the buffer, there has been large amounts of white 'dust' coating on everything, including the glass.

I just poked around the sand bed and it didn't seem solid, but this is a young tank, so that might not be an issue yet.

 

[sjames]

If you have a LFS, i would take a water sample from the tank to them and see what they get, also take a sample from fresh ASW to compare.

What salt mix are you using?

 

[sassyfrassy]

Don't mean to hijack this thread, I have a question about exp. dates on test kits. I have an API Master SW kit, and it has lot numbers on the bottles, but no exp. date. However, the lot numbers end in 09 - 3009, 0509 etc . Could this be an exp. date also as I know these reagents have a shelf life.

 

[Chris27]

Don't mean to hijack this thread, I have a question about exp. dates on test kits. I have an API Master SW kit, and it has lot numbers on the bottles, but no exp. date. However, the lot numbers end in 09 - 3009, 0509 etc . Could this be an exp. date also as I know these reagents have a shelf life.

I wouldn't worry too much, the liquid reagents tend to last a very long time. API, although much cheaper, are still reliable tests that will suffice for most testing needs, unless you're looking to pinpoint exact values - API uses a broad range with their tests vs. exact values, ie. the pH test goes in 0.2 increments vs. 0.1 increments like Seachem and some others.

 

[dwculp]

I would not use buffer, marine buffer is junk. Ok, it works, but it is FAR better to use a two part solution.

I would:
1. Drain the tank and do a 100% water change. Test the water before and after putting in the tank.
2. If I get the same results I would go buy a new bag of salt and do it again (btw, what brand of salt are you using?)
3. If I get the same results I would go buy new test kits and do it again.
4. If I get the same results I would ditch the rocks, clean the tank and try it again.

 

[bertoni]

What salt product is being used, and what is the SG? Alkalinity at 1.7 meq/L is very low for freshly-mixed saltwater. I don't see how the presence of silica will affect the carbonate level off-hand, so I wouldn't spend money on that test kit.

 

[uncleof6]

Funny that you should mention it, after I added the buffer, there has been large amounts of white 'dust' coating on everything, including the glass.

I just poked around the sand bed and it didn't seem solid, but this is a young tank, so that might not be an issue yet.

Sounds to me, like the salt mix is creating sw with a low alkalinity, and a rather normal range for calcium. (have you tested the new water for calcium?) Starting off with an imbalance between Alkalinity and Calcium. Sounds to me like you are dosing a balanced additive, and this will only drive the calcium up. The level of calcium now, is at a level, that any alkalinity added, is causing abiotic precipitation of calcium carbonate (the white dust) and driving your alkalinity back down to where it started. It is also very probable that your magnesium level is very low also, it should be 1200 - 1300+ ppm. Magnesium inhibits the abiotic precipitation of calcium carbonate.

If you have an imbalance between calcium and alkalinity, dosing a balanced additive, only makes the imbalance worse, and you wind up where you are now.

Sounds like the salt you are using is not mixing up anywhere close to natural levels, and if it is not just a bad batch, I would change brands. (natural levels: alk -- 7 dKH, calcium 410ppm)

Jim

 

[danch]

Funny that you should mention it, after I added the buffer, there has been large amounts of white 'dust' coating on everything, including the glass.

So you dose buffer (probably a carbonate blend) into water with a high Ca and something precipitates out? Mebbe your Ca is so high that all the carbonate you put in does nothing but pull the Ca down a bit by precipitating calcium carbonate? This reaction runs until you're out of carbonate hardness?

I'm not a chemist, but maybe one will speak up to shoot down my lame theory and offer a better one!

 

[Chris27]

So you dose buffer (probably a carbonate blend) into water with a high Ca and something precipitates out? Mebbe your Ca is so high that all the carbonate you put in does nothing but pull the Ca down a bit by precipitating calcium carbonate? This reaction runs until you're out of carbonate hardness?

I'm not a chemist, but maybe one will speak up to shoot down my lame theory and offer a better one!

You're not lame - I think you are actually on the right track with that idea.