Which Alk/Ca values should I believe?

[plankton]

I have a New Years resolution to keep my tank chemistry as stable as possible to allow my corals to thrive. They are doing fine now with good growth and color and want to keep it that way. However, depending on the test kit I use I'm getting different results so not sure exactly what the 'now' state is. How do I go about deciding which is correct? Note, test kits are recently purchased new and I am following manufacturers directions. I'm currently dosing Bionic 2-part, Iron and RedSea (No3-Pox; alcohol/vinegar). Top-off is RO-DI of course. I also have Trident coming so curious what results I get from those test kits.

Alk	Salifert	4.8
	AquaForst (AF)	9.5
	Hanna	7.9
Calcium	Salifert	420
	AF	390
	Hanna	461

 

[plankton]

Tank temp is 78 and Salinity is 1.026 and 52.2 conductivity.

 

[X-37B]

Something is not right.
My Hanna, which I use every day for alk, is always within .3 of salifert.
I also use elos as a third backup and its close too.
I only use salifert for calcium as it never varies. I test it maybe every 2 months.
I do run a carx that keeps everthing stable.
I would run the test on a new madeup batch of salt and go from their.
What are the stated values of the salt you use vs testing results.

 

[reef_ninja]

Your results for the alk on the salifert look like you are following the low res directions. If that’s the case, you should double the value, which would make it equal to your aqua forest reading. Or maybe I’m reading into it too much

 

[plankton]

Something is not right.
My Hanna, which I use every day for alk, is always within .3 of salifert.
I also use elos as a third backup and its close too.
I only use salifert for calcium as it never varies. I test it maybe every 2 months.
I do run a carx that keeps everthing stable.
I would run the test on a new madeup batch of salt and go from their.
What are the stated values of the salt you use crap testing results.

I'm using LiveAquaria Reef Salt. So, I should mix a fresh batch of salt with RO/DI water then use all three test kits to confirm stated values right?

PS I currently dose 20 ml of Bionic 2-part (20 ml of each part) on at 25G lagoon with about 35G of total water volume to keep values stable. Take is 9 months old.

LiveAquaria Reef Salt Parameters
Salinity: 35 ppt (1.026 sg)
Calcium: 400-450 ppm
Magnesium: 1,350-1,450 ppm
Alkalinity: 8.0-9.5dKH

 

[X-37B]

I'm using LiveAquaria Reef Salt. So, I should mix a fresh batch of salt with RO/DI water then use all three test kits to confirm stated values right?

PS I currently dose 20 ml of Bionic 2-part (20 ml of each part) to keep values stable

LiveAquaria Reef Salt Parameters
Salinity: 35 ppt (1.026 sg)
Calcium: 400-450 ppm
Magnesium: 1,350-1,450 ppm
Alkalinity: 8.0-9.5dKH

That would the best way to validate your test results.
I run esv 2 part in my frag tank.
When I got to 50ml a day in my 120 I went to a carx.

 

[X-37B]

That would the best way to validate your test results.
I run esv 2 part in my frag tank.
When I got to 50ml a day in my 120 I went to a carx.

I also use esv salt as it always mixes up to the same. I then have to reduce alk to get to my current level of 7.

 

[plankton]

Your results for the alk on the salifert look like you are following the low res directions. If that’s the case, you should double the value, which would make it equal to your aqua forest reading. Or maybe I’m reading into it too much

Good thinking unfortunately I used full 2ml, etc. I'm mixing 4G of RO/DI then will add salt/heater/pump and run overnight then test using all three kinds of test kits again then probably throw away any results that are wildly outside the expected range from manufacturer. Liveaquaria ReefSalt I'm told is basically Fritz Pro Mix (RPM) salt.

 

[HB AL]

Assuming your doing all the tests correctly I would mix up some salt then test it with your current tests. The values should be exact. Read the info on the salt and see what values for alk should be at the salinity level you mixed it up at. This will tell you which test to trust.

 

[Randy Holmes-Farley Verified Community Expert]

Are you sure you are not reading the Salifert alk test backwards? Be sure that the way you are reading it, more titrant added to get to the color change means higher alk. many folks make that mistake with Salifert kits.

 

[reef_ninja]

Good thinking unfortunately I used full 2ml, etc. I'm mixing 4G of RO/DI then will add salt/heater/pump and run overnight then test using all three kinds of test kits again then probably throw away any results that are wildly outside the expected range from manufacturer. Liveaquaria ReefSalt I'm told is basically Fritz Pro Mix (RPM) salt.

For the salifert alk, for the full res, you should be using 4 mls, not two. You need to double the value

 

[plankton]

@reef_ninja - Thanks! Used 4ml and got more realistic results.

OK mixed 4G of RO/DI with LiveAquaria salt to bring salinity to same as tank 1.026 and temp 78 and let it run over night. [Will do water change later]

Here are the test results of LiveAquaria which manufacturer has the following targets for their salt : [Hanna is actually more aligned with the manufacturer specs]

LiveAquaria Reef Salt Manufacturere Parameters
Salinity: 35 ppt (1.026 sg)
Calcium: 400-450 ppm
Magnesium: 1,350-1,450 ppm
Alkalinity: 8.0-9.5dKH

Parm	Test Kit	Value
Alk	Salifert	10.9
	AF	11.2
	Hanna	9.3
Calcium	Salifert	550
	AF	500
	Hanna	489
Magnesium	Salifert	1650

 

[reef_ninja]

Your welcome

 

[plankton]

For the salifert alk, for the full res, you should be using 4 mls, not two. You need to double the value

Thanks reef_ninja for catching that!

 

[plankton]

Assuming my test results are kinda close then LiveAquaria runs Alk a little on the high side. Given my high measured levels of Magnesium, I've orderd another test kit to double check. PS I don't believe the high AF alk level of 11.2 but read the instructions twice and titrated until the color change they pointed out. I just redid the AF and still get 11.2 dkh which is really high result. If hanna makes a Mag test kit I'll buy one and if they don't will get an AquaForest one to check against what I get via Salifert.

 

[elysics]

I'd go by what the results with a reference solution or standard say, not with which value is the most convenient. Numbers on salt buckets can be off. And if you have 3 tests with 3 results, that doesn't mean that the average of them is correct. They might all be off, or the most extreme one might be correct, without checking you wouldn't know.

In general I wouldn't even use a test that I haven't checked against a reference solution. The one by fauna marin covers a bunch of parameters. Some you can DIY.

 

[plankton]

I'd go by what the results with a reference solution or standard say, not with which value is the most convenient. Numbers on salt buckets can be off. And if you have 3 tests with 3 results, that doesn't mean that the average of them is correct. They might all be off, or the most extreme one might be correct, without checking you wouldn't know.

In general I wouldn't even use a test that I haven't checked against a reference solution. The one by fauna marin covers a bunch of parameters. Some you can DIY.

great feedback and will try to get some independent standards to test against.

 

[plankton]

Haven't found independent standards to test against yet but will continue looking. Got APEX/Trident hooked up and initial reading of tank was

Neptune recommends running it for several days before running their calibration standard through so will see how tank chemistry compares then. I haven't hooked up the APEX DOS to Trident for auto dose adjustments but that will be next step.