Alkalinity at 0? Ca at 360, ph 8.2

[Ripside]

Been gone a few days, Calcium has slipped down to 360ppm.

I just got my Alkalinity test last week - it was reading very low, 0.3, around there. I was adding Kent Superbuffer daily, and it was coming up. I left for 3 days, and now Alkalinity is down to zero.

pH is 8.2, where I always try to keep it. Its been very stable at 8.2 since I added a canopy, and removed the glass top.

What's the best way to safely bring up alkalinity, without increasing Ca? With 0 alkalinity, I'm expecting a pH plunge.

I verified the test results by doing it twice. Readings were very low to start, so this isn't a big change, but I'm getting frustrated trying to bring it up.

Its the Salifert test kit, and was working last week, so I don't think it expired on me in that amount of time.

ALSO, is there a way to "verify" the results, from using a calibration solution, like some baking soda in water, that sort of thing?

 

[ek9vboi]

WATERCHANGES!!!

I have no idea why your levels can get that off unless you are not doing the regular waterchanges. pH I can understand, but everything should be up to par with the waterchanges unless you have SPS.

I would recomend you to do a few big waterchanges (20g) and see where the levels are. Do 2 to 3 of these withing a month. When you see what level they are at, start dosing a 2 part to bring them up correctly. Once you have seen the levels up to standards... drip kalkwasser to keep the levels. It will also help keep the pH up too.

 

[Ripside]

I just did 2 20% water changes last week...

No SPS'.

Using RO/DI and "Instant Ocean" salt.

I'm going to mix up a small batch of SW, which should have normal buffering levels in it, of course, to see what the alkalinity shows. I suppose my test kit could be off.

I don't get my Ca being good (a little low, but again, I was gone a few days), pH being good, but Alk. being so low.

 

[ReeferAl]

It is impossible to have an alkalinity of 0 with a pH of 8.2
It could be very low, but cannot be 0 (the pH would have to be about 5 for the alkalinity to truly be 0). Even with a very low alkalinity I find it hard to believe that the pH would be 8.2 as it would tend to drift down with low alkalinity. A very low alkalinity with a pH in the upper 7's would be more believable.

As far as a calibration solution, you might try posting in the chemistry forum and see if Randy H-F has a suggestion. I suspect a caliration of the kit and technique is in order. Water changes won't hurt, but I would be hesitant to do any other changes until you can verify your true alkalinity level.

Allen

 

[Mr31415]

I would not trust that reading. AFAIK it is not possible to have those parameters and alk at about 0. It just does not make sense...

 

[Ripside]

Okay - SW batch shows at 7.0 dKH, 2.51meq/L Alkalinity.

Now I'm confused.

 

[Ripside]

Well, if the readings are right, I'm afraid to start dosing any hardness additives, which might drive up Calcium, since Ca is already at 360 (I understand you can't push up one without affecting the other).

I took these readings from my refugium - going to try from the tank.

 

[Ripside]

Same result. I run out of the 1ml of drop-by-drop solution before the color changes to pink.

I understand its not really "zero", but its close - the lowest reading on the chart with the kit is 0.3 - I did the low-res test, and still went past that mark, but the solution did change after another 0.4ml. So its near zero.

 

[ReeferAl]

<a href=showthread.php?s=&postid=8121440#post8121440 target=_blank>Originally posted</a> by Ripside
Same result. I run out of the 1ml of drop-by-drop solution before the color changes to pink.

That means your alkalinity is very HIGH, not low. I don't have the chart right now, but your alkalinity is "off the chart". You can get the correct alkalinity by refilling the syringe and continuiong the titration until you do get the color change. There is then a formula at the bottom of the chart or you can add the alkalinity reading from the second fill of the syringe to the max alkalinity obtainable from the chart on the first fill (the top line of the chart).

Allen

 

[Ripside]

I'm using the entire 1ml solution - according to the instructions, I do this:

KH in dKH = (1 - reading from syringe) x 16.

The syringe is at zero after using the entire 1ml solution.

KH in dKH = (1-0) x16
KH in dKH = (1) x 16 = 16.

Okay.

Got it.

The chart provided is used by reading ml's from the syringe, NOT the calculated value (1 - reading on syringe). They're not very clear about that.

Holy cow, why is my alk so high? I've only used the Kent Superbuffer like once or twice in the last month, according to directions... and I've done many water changes since it was used.

My mixed up SW dKH is, according to my CORRECTED calculations, about 9.0, when mixed to 1.025.

Is that the problem? The mix is raising the Alk too high?

 

[Ripside]

Also, I feel a recommendation for lots of PWC coming. Should I just leave everything alone, or is this alkalinity a danger to polyps (GSP's, shrooms, zoo's and palythoas) and/or fish?

 

[Ripside]

PS - I was using Purple-Up, up until a few weeks ago when I ran out... I thought though that it just raised Ca levels, and I've been keeping an eye on that reading.