Aquavitro Salinity alk concerns, anyone else using it?

[cptbjorn]

I got a bucket about 6 months back and have been using it for water changes and so far I have been mostly happy with it. When I first got it I mixed up a batch, let it circulate for several hours and tested with my Salifert alk/Ca/Mg kits, and they all matched the results on the label within a reasonable margin of error so I haven't bothered since to test any saltwater batches since.

But over the last couple weeks I've been trying to get a stable daily two-part dose again and it seemed like my water changes were actually decreasing my alk, even though the tank usually stays around 9dkh while the WC water is supposed to be 10.5 or so and should be increasing it instead.

So I just retested and as far as I can tell at least with my bucket, newly mixed Aquavitro salinity tests at 10.5dkh alkalinity but then slowly precipitates some over a few days or a week and settles in around 7-7.5dkh. I see a couple discussions elsewhere on the web about this but I know there are several people in the area using this salt and wondered if anyone else is finding the same thing? Or would be willing to test?

I'm going to do some more tests to confirm my results, but it seems from my research that this may be a known issue and that Seachem is possibly starting to recommend mixing up a new batch of saltwater the same day as each water change...

 

[holdendaniel]

I got a bucket about 6 months back and have been using it for water changes and so far I have been mostly happy with it. When I first got it I mixed up a batch, let it circulate for several hours and tested with my Salifert alk/Ca/Mg kits, and they all matched the results on the label within a reasonable margin of error so I haven't bothered since to test any saltwater batches since.

But over the last couple weeks I've been trying to get a stable daily two-part dose again and it seemed like my water changes were actually decreasing my alk, even though the tank usually stays around 9dkh while the WC water is supposed to be 10.5 or so and should be increasing it instead.

So I just retested and as far as I can tell at least with my bucket, newly mixed Aquavitro salinity tests at 10.5dkh alkalinity but then slowly precipitates some over a few days or a week and settles in around 7-7.5dkh. I see a couple discussions elsewhere on the web about this but I know there are several people in the area using this salt and wondered if anyone else is finding the same thing? Or would be willing to test?

I'm going to do some more tests to confirm my results, but it seems from my research that this may be a known issue and that Seachem is possibly starting to recommend mixing up a new batch of saltwater the same day as each water change...

i heard from lfs that talked to seachem that mix it no more then 8 hours. add salt 1 cup at a time(will create a chemical reaction making a brown skim) i found it to leave a nasty white slim all over everything

 

[Boomer]

SeaChem is working on this issue and running some mixing tests and will change the instructions. They use anhydrous salts in their mix and this can creat issues with mixing. You are best off to mix it up very slowly over a few hours and try to a hve good circulation.

 

[cptbjorn]

huh, I'll have to do some experimenting since I just need a gallon or two at a time... sounds like a need an hourglass kind of contraption to slowly add the salt to a gallon pitcher of water with a circulating pump.

 

[Chichas01]

Or you can get one of these:
Mixer, 5 Gal, Use With Drill - Painting Tools - Equipment & Supplies - Janitorial & Painting : Grainger Industrial Supply

Got mine at McClendons.

I started using one and mixing my water for a couple minutes with this in a five gallon bucket for before transfering to my water can that has a couple fo power heads in it. Seems to have vastly improved the mix and that that slime that can build up on the sides of the can.

 

[Boomer]

Yes Chich, I posted on drill type paint props just last week for the same reason on amother fourm for Aquavitro. You can mix a batch in ~ 5 min

 

[cptbjorn]

Thanks for the suggestions, the paint mixer sounds like a great idea and I know they make small ones used for stirring gallon paint cans.

I have a pitcher that has a line around the inside that is exactly one gallon and I have a .1g accurate scale I use for mixing two part, sounds like I'm going to figure out exactly how many grams it takes to make a gallon to 1.026 and then slowly pour it in while stirring and I should be able to make a gallon in just a minute or two which is perfect for my uses.

 

[DolphinLVR]

I stopped using Aquavitro cause it took so long to clear up as well as the brown residue it left in my mixing tank.

 

[NWDiver]

Hmmmm, I use salinity, I will do some tests this weekend.
I typically mix 50gal at a time, and I add the mix 1 cup at a time, then check the salinity the next day and add the salt correction.
I have a pair of mag 5's that mix the tank, one up and one sideways.
I often let it mix several days, but I don't think I have checked the alk much after 24 hours. I will strart the mix tonight and check the water in the morning. I can let it mix until Sunday night. I will do an alk test twice a day and see what I get.
Boomer> At what rate should I add the salt?

 

[FreakinReefin]

I went back to Tunze from Salinity...however I kept the buckets and dump all the Tunze salt into the Salinity buckets

I hate the white slime and the SLLOOOOOOOOWWW mixing times...but one I got it in the tank it was fine.

Tunze ROCKS though!

 

[NWDiver]

I have wondered about the complaints, either I've been lucky or I'm doing something different. I have had none of the slime issues. I have always mixed for 24 hours so the time has not been much of an issue. The water is typically clear in about 2 hours for me.
My RO water is probably cooler than others, but other than that I have no idea...

 

[NWDiver]

If someone would send me the thread on this that they saw elsewhere, that would be great.

 

[cptbjorn]

The main one I'm referencing is this one on RC

 

[Boomer]

That 1 cup / 50 gal at a time should be fine, say / hr or / 1/2 hr.

 

[NWDiver]

Thanks Boomer.
I understand the issue of precip causing the alk\Ca to drop, but what about alk dropping over time say several days of mixing? I plan to test this over the weekend, but what is your take? My mix container is an open top 55gal and it is in a 3500sq foot shop, so I don't expect CO2 to be an issue.
I will divide the salt per cup into 1 hour mix time, should work out to be every 2 and a half minutes or so per cup, does that sound good for a test?
>cptbjorn thanks for the link! I will post the results here.

 

[Boomer]

what about alk dropping over time say several days of mixing?

We would need to see the pH, Alk Ca++ and Mg++ each day. The only thing in a fresh batch that can do this is abiotic or issue of precip causing the alk\Ca to drop. The Alk can not just vanish, unless the salt has other things going on killing the Alk, like the production of acids, which I find hard to believe.

 

[NWDiver]

That was my impression Boomer, but you know, "ask the expert"
Here is the first update:
Calibrated both pH probes and the refractometer.
55 gallon open top plastic barrel. The top will remain open.
The Barrel is mixed by two mag5 pumps one pointed up and one sideways.
I added 35 gallons of RO water to the barrel.
I then added a cup of Salinity every 4 minutes until I reached 15 cups
The water was mostly clear at this point.
The water temp was 57F and the pH 8.2

I tested the water 4hours and 16 minutes later
All tests are elos and I checked the expiration dates were good.
Lab grade thermo
Water sat on the refract for 5 min to temp stab.
The water is crystal clear
Water temp 63F
pH 8.2
Mg 1300
Alk 8
Ca 400
Salinity 1.026 (Lucky guess on the measuring!)
I will check the stats in the morning.

 

[Boomer]

Looks good so far

 

[NWDiver]

The salt has been mixing ~22 hours and the results are:

Temp 71F
pH 8.06
Alk 7.5 (I checked this twice)
Ca 400
Mg 1300
Salinity 1.026

 

[cptbjorn]

I started a (much smaller) experiment, it is a gallon pitcher with a tiny hydor pico pump in it for circulation. I found that if I fill the pitcher to a line near the top it takes 140.0g of aquavitro to hit 1.026, so I filled to the line, weighed out my salt and stirred it vigorously with a paint stirrer in a cordless drill while very slowly adding the salt. Splashed in a couple grams of salt, stirred until water was clear and kept repeating until in just 5 minutes or so it was all completely dissolved.

I heard it hypothesized that the temp increase from adding the salt might be causing the precipitate somehow so I kept a ds18b20 digital temp probe in while I dissolved the salt and the enthalpy of solution only raised the temp of the water 1.5F, which I doubt is enough to really do much.

I'm going to do tests at time intervals of 2^x hours with the temp probe, my refractometer and salifert alk, Mg and Ca tests. Here's the first two:

t=1:00
temp: 76.3F salinity: 1.026
alk: 10.6 Ca: 365 Mg: 1170

t=2:00
temp: 74.1F salinity: 1.026
alk: 10.6 Ca: 370 Mg: 1290

My bucket of Salinity lists the alk of the batch at 10.64 dkh, the calcium at 417ppm and the magnesium at 1370 so while the alk is right in line, the calcium and magnesium are still quite low, although rising. I would assume that the rising Ca and Mg are caused by them being present as slightly soluble hydroxides which the test kits aren't picking up until they dissolve fully or react with dissolved CO2 or some other unknown factor.