alkalinty?

[mitch303]

alright so yesterday i tested my alk and calcium levels and calcium was at 460 and alkalinity was at 7dkh. so today i started dripping kalk in my sump to get my water level back up from evaporation. so after i dripped the kalk i tested again and my dkh was at 5 and calcium at 420 i also checked my ph and it said 8.2-8.4 kind of hard to tell on the api test kit. and i did this test with the lights of in tank and refugium. so why is my alk so low today and ph is about normal? is it low because i was testing with the lights off? i think i need a ph tester or probe or something.

[neoalchemist74]

Magnesium is low.

[mitch303]

Ill test mag in like 10 minutes. I'm going to do a water change today and that brings my mag calc and alk levels to where they should be so should I start dripping kalk after the water change to keep my levels where they should be

[Randy Holmes-Farley]

I suspect the 5 dKH is a measurement error, unless you added massive amounts of limewater.
How much did you add?

[mitch303]

i added 1 tsp in a 1 gallon jug and dripped it in my sump about 1 drip per 2 seconds i stopped drippiung it and there is still a little more then half of the jug left.

[mitch303]

alright did my water change and tested my levels again mag came back at 1470 calcium at 440 and alk is still 5 dkh could i have a bad test kit.

[neoalchemist74]

Yeah those numbers don't make sense. seems like a test kit error. or out of date kit.

[mitch303]

do the apiu test kits have a expiration date anywhere on them?

[mitch303]

api*

[mitch303]

are my calcium and magnesium levels good though

mag-1470
calc-440

[mitch303]

using this 2 part doesnt make any sense to me say i have low alk level do i just add the alkalinty part and no cacium part or if all my levels are where i want them is this something im going to have to dose daily to keep levels maintained. or will kalkwasser maintain all 3 of these levels for me?

[mitch303]

ok so my test kit has about another 2 years till it is expired tested again and still came up with 5 dkh

[Randy Holmes-Farley]

Yes, the calcium and magnesium are fine. I expect there may be an alk test problem.

What salt mix are you using? Try testing some new salt water. :)

let's figure out the alk before we get to dosing methods, but generally one wants to use both parts equally. If you added both parts equally to boost alk to 7-8 dKH, which is a fine goal, you'll hardly notice any calcium rise. :)

[mitch303]

im using kents marine reef salt.

[mitch303]

i also want to know im planning on getting a reefkeeper lite or a apex controller how would i dose kalk with a controller i have a jbj ato with a aqualifter pump can i just add kalk to my top off bucket. will it dose to much when the jbj kicks on and wont it dose when my lights are on and raise ph. can i use a controller and another aqualifter to dose it seperately from my ato and use the controller to dose at night when my lights go off.

[bertoni]

If I were using a controller with kalk, I'd probably just set an emergency high-pH shutoff in case of trouble, and dose the lime as autotopoff, with some sort of peristaltic pump or the like, to provide a very slow stream. The JBJ might not add limewater slowly enough, depending on the size of the tank or sump where the limewater is being dosed.

[Randy Holmes-Farley]

OK, so try measuring the alk in the Kent salt and let us know what you get (and what salinity you made the new salt water).

[mitch303]

alright i will test that here in a day or so

[Kappapibeta]

I want to know what the experts use to check alkalinity. Which brand works best for you guys?

[Dana42078]

I want to know what the experts use to check alkalinity. Which brand works best for you guys?

I also wonder this because im having the same issue as the TS (5-6dkh), and also using a API test kit.

[HighlandReefer]

I want to know what the experts use to check alkalinity. Which brand works best for you guys?

I use the acid titration method for determining alk which is much less expensive and more precise than the hobby grade alk kits since it uses a properly calibrated pH meter to determine the end point, not color changes. ;)

[Kappapibeta]

What do you guys think about the accuracy of Hanna alk tester?

[msr224]

I use the acid titration method for determining alk which is much less expensive and more precise than the hobby grade alk kits since it uses a properly calibrated pH meter to determine the end point, not color changes. ;)

Do you have a link to this?

[bertoni]

http://www.reefcentral.com/forums/showthread.php?t=1583884

[HighlandReefer]

Do you have a link to this?

I added a few extras in this post which may help if you want to use HCL for your acid:

You can buy 0.1 N Sulfuric acid standard used as the titrant from: (you simply substitute the 0.1 N sulfuric acid for the 0.1 N hydrochloric acid with the same results)
Buying 0.1 N HCL can be difficult since there are shipping & other restrictions placed on it by most companies.

0.1 N sulfuric acid standard
http://www.grainger.com/Grainger/items/4YNA6?cm_mmc=Google%20Base-_-Test%20Instruments-_-Laboratory%20Supplies-_-4YNA6


If you own a business, you can purchase 0.1 N HCL from here. You will need to setup an account and the HCL will have to be shipped to your business. Any busines qualifies:

Lab Safety Supply
http://www.labsafety.com/Hydrochloric-Acid-01N-01M-1L-Poly-Bottle_s_146466/Ha-Hz-Chemicals_24539150/?ci_src=14110944&ci_sku=146466&CID=9PP001


It would be best to calibrate your pH meter using a 4 & 7 standard before you start the test. The pH test kits are not accurate enough for this procedure.



Easy part; Testing

Now take a sample of your aquarium water, you can use any volume but I like to use 100ml because my pH meter sits nicely in the cup without me holding it at this level. Stick in your pH meter to your sample. You should get the same reading you do when you stick it directly in your tank. If not start over with a clean sample container. Now draw up some 0.1 N HCl solution in to your 5ml syringe. And start dropping into your sample 0.5 mls at a time and watch your pH meter. You are adding a strong acid so your pH should fall rapidly. Once your pH hits 5 start to slow down and add a drop at a time until your pH hits 4.2 . The reason we are shooting for 4.2 is because this is the point where all available carbonates have been converted to carbonic acid. You would think this would be pH 7 but it's not as carbonic acid is a weak acid and you have to really saturate it etc. Anyway, once you have reached pH 4.2 you are done and now can calculate your total alkalinity.


Alk mg of CaC03 /L = A x N x 50,000 / mL of sample

Where A = ml of acid added

N = normality of your HCL

So if you added 4ml of 0.1 HCL before you hit a pH of 4.2

4*0.1*50,000 / 100 = 400 ppm CaC03 equivalents or your total alkalinity is 8 meg/L (mg/L / 50 = meg/L) or 22.4 dKH.


The above information was taken and corrected from this thread:

http://www.reefcentral.com/forums/showthread.php?t=1583884&highlight=acid+titration+alkalinity

Randy provides further details in this article:

What is Alkalinity
http://www.advancedaquarist.com/2002/2/chemistry



For converting ppm calcium equivalent to dKH or meq/L you can use this calculator:

http://www.saltyzoo.com/SaltyCalcs/AlkConv.php

[HighlandReefer]

If you want to get more precise results for your alk test using the acid titration method or even meters and test kits, you will need to filter your sample water using a 0.3-0.5 micron size filter. What this does is removes suspended calcium carbonate particles and micro-organisms that contain contain calcium carbonate which can influence your final alk reading since the calcium carbonate will dissolved in the test procedures and be added to the final results. Some hobbyists dose Purple-up for example, which can influence the final alk reading considerably. If you use kalk water, calcium reactors, kalk reactors or use sodium carbonate (baked baking soda) these can add to the amount of suspended calcium carbonate as well. ;)

FWIW, there are a lot of factors found in reef tank water that interfere with all the test kits and equipment we use which can throw off the test kits & meters making them less accurate. ;)

It may be easier to just shoot for the middle of the recommended range for alk (7-11 dKH), this way you should be fairly safe. :)

[msr224]

Thanks Bertoni and highland reefer.

A lot to read.....I'm sure that it's not too bad once you have everything together but it seems difficult just reading it.

[tmz]

I use a Salifert alk test kit and cross check it with an api. Works well enough for my purposes.

[HighlandReefer]

You're welcome. ;)

[msr224]

You're welcome. ;)

I got to quit reading stuff cause it causes issues....I overdosed Alk part of randys #1...... Cloudy tank......Ph dropping almost immediately.....everything ok and tank clearing but had to blow "dust" off of stuff....

geesh....

I have been working to get the Mag up for a while and I got a little excited....finally tested up over 1330 yesterday and so I did Alk and calcium today working to get them up.....

[HighlandReefer]

When you want to increase alk levels, using baking soda is safer since it will not increase your pH too high. It is best to drip baked baking soda for maintenance of your alk level if you decide to use it do to low pH issues. ;)

[wesley6610]

Quick question, would one need to recalibrate their pH meter using a 4.0 standard or could we just use the pH probe calibrated with the 7 and 10 like on an Apex system?

[HighlandReefer]

Using pH standards that reflect the range you are most interersted in are what is recommended. Calibrating your pH meter using 7 & 10 & then checking to see if the 4 is read properly may be one way to verify accuracy. It should be close, but you really don't know until you check it. ;)

[msr224]

When you want to increase alk levels, using baking soda is safer since it will not increase your pH too high. It is best to drip baked baking soda for maintenance of your alk level if you decide to use it do to low pH issues. ;)

So...doser in my future then? Running apporx 60 gallons would I be better with a CR?

[bertoni]

People seem successful with calcium reactors and the DIY two-part in that size tank. It's a personal choice. A doser for the 2-part might be useful for keeping a lot of stony corals, IMO.