Boomer / Randy - Please help me understand dissolving salt

[Icefire]

**That sounds plausible... If Ca and Mg precipitated out then it could account for the fact that my Ca is only 452mg/L and not > 500mg/L as it usually is with Tropic Marine Pro Reef...**

CA is related to salinity, low SG = low CA.

Personnaly, I think the salt is in the sand. I would raise a sand store for 15 min and let it settle, thn retest.

When I do 5g of saltwater and mix it manually, there is some salt remaining. When I 1st filled my tank, I had a layer on the bottom and used a powerhead for several minutes to disolve it.

You need ~35g per 965ml water for 35ppt but each salt is different

 

[marsh]

Icefire
I agree but wonder about a couple of things.
1. If the salt is in the sand or more likely on top causing a dust up may bury some salt and create unknown problems in the future.
2. Creating a dust up now might create nidus' (?nidi) for aragonite to deposit and a further loss of ions. I don't know if this true...would like to hear some comment.

That is why I thought vacuuming the surface was a better option.

One of the objects is to save his current water since artificial mix is so expensive in SA. I think he ought to plan for additons of Ca, Mg, and Alk before the salinity is raised more. Maybe wait several days to see how things settle out. Tanks last a long time..setting them up correct (or as best is possible) will save unknown headaches in the future.

 

[Icefire]

his foggy water is probably just sand particules because he run already his 6100+closed loop and has very very fine sand.

It's a new tank = no bacteria to keep the dust down.

I would still create a massive sandstorm to stir up the sand than let it settle. The salt is in there unless he got a bucket who was a fake.

 

[bertoni]

I wouldn't worry about stirring up the sand causing problems. I think there might be some precipitation happening, but after considering the situation, I don't think that can be the whole story. I'm not sure there's enough magnesium or calcium to cause the SG to be half of what's expected, even if all of it precipitated.

 

[Billybeau1]

Yes, there is definitely a piece of the puzzle missing here (so to speak)

Strange indeed Jon.

 

[Mr31415]

Icefire - I am sure the cloudy water is not sand. The tank had been running with just RO/DI water and the sand bed for 24 hours and the water was crystal clear the whole time. Only once I started adding the salt the water started getting cloudy. And the colour is a whitish colour.

bertoni, Billybeau1 - my only conclusion is that it is a combination of factors. I think some Ca and Mg precipitated out due to the way I added the salt - hence the cloudiness. Furthermore - based on past experience and common sense, and based on the way I added the salt (right infront of a 5283 g/h pump so about 85% of all visible salt dissolved almost instantaneously - the rest settled in a smallish (+- 1kg) pile beneath it and was dissolved in 2-3 hours) - I can only conclude the two buckets of salt I had was bad somehow...

Here are a couple of pictures of the cloudy water:

Side view with my Hanna probe:

After almost 25kg of TMPR salt (final SG after 1 bucket was about 1.007):

Tunze drawing in the undissolved salt beneath it - this salt was all visibly dissolved in 2-3 hours, and this was the total amount of visible salt on the substrate after 25kg was added.

Nice shot of less salty water from sump mixing with more salty water from tank

Next day - after 68kg of salt was dissolved this way - still cloudy, SG = 1.014:

 

[Mr31415]

Oh by the way - my SG is now 1.0245. I added another 30-35kg of salt over the course of 24 hours by draining 110l of water into a container, adding enough salt to make about 1.058 with a powerhead, once stabalised and dissolved I pump it back, then let it mix thoroughly in the tank before repeating this. After doing this 5 times I got it raised from 1.014 to 1.0245 - exactly what my calculations said it would.

So lesson learned? Never mix salt in the tank itself - always mix it in containers. Why? That I hope someone on this forum can answer.

 

[marsh]

I can only conclude the two buckets of salt I had was bad somehow...

One possibility is since salt is so expensive in SA, maybe someone cut the TM with cocaine . If that is so monitor your fish for typical signs....rubbing their nose on the glass...excessive euphoria..

 

[Mr31415]

hahahaa

 

[marsh]

In terms of setting up a tank, putting salt directly into a large mass of RO/DI water shouldn't not have been a problem. The sand bed complicated things in your situation.

Some questions:
1. Was there something, i.e. ions, in the water prior to addition? I know you used RO/DI but perhaps the sand leached. I guess the sand was fine aragonite?
2. Localized high concentration as already mentioned.
3. Brazil Nut effect during transport to SA causing large inhomogeneity in the salt bucket.


But 25 -30 kgs!!!!

 

[Mr31415]

1) The sand was a layer of fine crushed coral and a layer of coral sand.
2) Only in a small place - not really enough localised salt to cause this much cloudy water I think
3) Weird thing is just I have never had a bad batch of salt before from my LFS.

 

[marsh]

Whenever you get around to it post your alk, mg, ca, ph (filtered and unfiltered) results as well as expected results from prior mixing or current salt at the same salinity. It will be interesting.

BTW is the water clear yet?

 

[Mr31415]

Nope as cloudy as in the pictures. I am running a small amount of GAC - maybe that will help.

 

[marsh]

I read somewhere on RC that some guys use an actuall white sock....not the usual 100 micron sock but it might speed up the cloud reduction.

 

[Boomer]

Mr

Sorry I missed your post but it appears it has been taken care of. I do not have time to read all the posts. That looks like a nice meter. What are you calibrating it with and have you played with the DO ?

Something that Marsh brought up on one of the first posts. Almost all saltsa are slightly hydrated and is why when you mix up 35 gr you do not get 53 mS or 35 ppt or an SG of 1.0264. On the link Marsh posted, on Craig's salt assay, you will see where he points this out. He weighs out 35 gr . kg and then measures the salinity, which is always well below 35 ppt, due to all the water, so you always need more than 35 gr due to x gr of water to get 35 ppt.

 

[Mr31415]

Boomer - yes it is a nice meter. We (you and me) disucssed the salinity part in depth a couple months ago. The DO is not yet calibrated so I am still trying to get it working properly.

About the salt - I mixed 68kg in to 2000l water and that gave me 1.014 - which is in my opinion much lower that the fact that the salt is slightly hydrated would influence it by.

I still have no acceptable answer as to why my water was cloudy and why 68kg of salt mixed in to 2000l of RO/DI water only made 1.014 so any comments you might have - please let me hear them!

 

[bertoni]

I thought the water was up to 1.024 now?

The cloud could have been calcium carbonate precipitation or substrate. If you let a sample of water settle, you could do some tests on the solids. If it bubbles in vinegar, it's likely calcium carbonate.

 

[Mr31415]

Yes bertoni - after I added an additional 35kg of salt! The cloudy water is now clear again....

I.e. the SG is 1.024 after about 102kg of salt in 2000l of water.

 

[bertoni]

Ah, I see. Good question, but I'm not sure about the answer. Table salt is likely very large component of any of the salt mixes, and that can't really do very much except dissolve or sit at the bottom of the tank. Perhaps the rest of the salt is undissolved (in the substrate), or you got an amazingly bad batch of salt. I think we've double-checked the numbers for the amount of salt a few times, right?

 

[Mr31415]

Yup all figures were double checked. I cannot believe it is undissolved salts on the substrate since today, 6 days later - the SG is *exactly* what it was 6 days ago. If there were undissolved salts then surely the SG would have marginally increased?