Boomer / Randy - Please help me understand dissolving salt
- Thread starter Mr31415
- Start date
By my calculations you have ~25.5 kgs of salt undissolved....based on Bingman's study http://web.archive.org/web/20001215...m/fish2/aqfm/1999/mar/features/1/default.asp.
You say the solution is cloudy and ~1 kg is on the substrate meaning the remainder is particulate mix suspended in the water column. Tomorrow your sg should be ~1.0236 if the water is clear and your assumption of 1 kg lies on the substrate is correct. If is not in that ball park more is on the substrate than you think.
Problems you face:
1. Undissolved Tropic Marin on the substrate
2. Possible insoluble precipitate on substrate or suspended...i.e. Calcium Carbonate or Magnesium Carbonate and lowered alk
Some thoughts:
1. Wait 24 hrs and retest
2. Increase temp to 78-80 F
3. Turn on skimmer
See what the sg is and make some decisions:
1. If there is a substantial difference from estimates vacuum top of substrate into a clean, plastic garbage can. Check sg/salinity....add TM until to the desired sg/salinity.
Another possibility would be to create a sand storm with your Tunze. There might be complications though.
2. If the sg is near estimate consistent with 1 kg on the sand...I would still do vacuuming of sand...
3. sg 1.024 be happy
Remaining Problem
Calcium carbonate or Mg carbonate may have precipitated. Check Alk, Ca, Mg and dose accordingly.
Further salt additions should be completely dissolved in a separate container.
You say the solution is cloudy and ~1 kg is on the substrate meaning the remainder is particulate mix suspended in the water column. Tomorrow your sg should be ~1.0236 if the water is clear and your assumption of 1 kg lies on the substrate is correct. If is not in that ball park more is on the substrate than you think.
Problems you face:
1. Undissolved Tropic Marin on the substrate
2. Possible insoluble precipitate on substrate or suspended...i.e. Calcium Carbonate or Magnesium Carbonate and lowered alk
Some thoughts:
1. Wait 24 hrs and retest
2. Increase temp to 78-80 F
3. Turn on skimmer
See what the sg is and make some decisions:
1. If there is a substantial difference from estimates vacuum top of substrate into a clean, plastic garbage can. Check sg/salinity....add TM until to the desired sg/salinity.
Another possibility would be to create a sand storm with your Tunze. There might be complications though.
2. If the sg is near estimate consistent with 1 kg on the sand...I would still do vacuuming of sand...
3. sg 1.024 be happy
Remaining Problem
Calcium carbonate or Mg carbonate may have precipitated. Check Alk, Ca, Mg and dose accordingly.
Further salt additions should be completely dissolved in a separate container.
Last edited:
Bertoni I get ~37.5 gms/L to make a 1.0264 sg solution based on Bingman's study....I could be wrong...but I'm trying.
I am sure Mr31415 has done a dilution experiment to get present numbers.
Also in his link it did state that the water was slightly cloudy.
I guess we'll get some more answers later as he lives in South Africa.
I am sure Mr31415 has done a dilution experiment to get present numbers.Also in his link it did state that the water was slightly cloudy.
I guess we'll get some more answers later as he lives in South Africa.
Last edited:
I did some searching on prior postings and found one by Boomer on Reef Crystals stating it takes ~41 gm/L of RC to make up a 35 salinity solution. That made me look up Bingman's article to get some idea for Tropic Marin. You might want to check my calculations/results so I don't give out misinformation. I had my spread sheet but erased it....
Anyway your idea is that the various gms/L by various manufacturers is do to salt hydration?
Anyway your idea is that the various gms/L by various manufacturers is do to salt hydration?
Last edited:
Mr31415
Active member
Tripspike - nope I have been using TM Pro Reef for a year now... Never been wrong when pre-mixed in a container.
bertoni - 35g per 1kg of water gives 70kg for 2000l - I have poured in 68 kg in 2000l and my SG is 1.014 this morning.
marsh - all the salt has now dissolved and the SG is still 1.014. The water is also still milky cloudy. Temperature has been 24.5C (76F) since yesterday evening - i.e. normal reef temperatures. Skimmer has been running since I had only plain RO/DI water in it. It now makes a nice fine mist of bubbles so I can see there is lots of salt content in the water - just way less that I was expecting. The thing about the substrate and why I cannot believe there are any more undissolved salt is that it is a very fine sand so any coarse particulate matter will lay on top of it - and with the given temperature and flow in the tank and the way I poured the salt bit by bit in - I just cannot see how there could be any salt left on the substrate.
bertoni - yes the water is just as cloudy as yesterday afternoon. That was 16 hours ago.
marsh - Like I said I always use TM and the 35g / 1kg of water is quite accurate - maybe 0.001 out but that is not the current problem... Even on the bucket it says a 25kg bucket makes 750l water - I poured in 2.66 buckets.... That should not give 1.014.
Now I am really concerned since it does not make sense just to keep on dumping salt into the water until SG is right if I am adding too much - the rest of the salt must be somewhere?
bertoni - 35g per 1kg of water gives 70kg for 2000l - I have poured in 68 kg in 2000l and my SG is 1.014 this morning.
marsh - all the salt has now dissolved and the SG is still 1.014. The water is also still milky cloudy. Temperature has been 24.5C (76F) since yesterday evening - i.e. normal reef temperatures. Skimmer has been running since I had only plain RO/DI water in it. It now makes a nice fine mist of bubbles so I can see there is lots of salt content in the water - just way less that I was expecting. The thing about the substrate and why I cannot believe there are any more undissolved salt is that it is a very fine sand so any coarse particulate matter will lay on top of it - and with the given temperature and flow in the tank and the way I poured the salt bit by bit in - I just cannot see how there could be any salt left on the substrate.
bertoni - yes the water is just as cloudy as yesterday afternoon. That was 16 hours ago.
marsh - Like I said I always use TM and the 35g / 1kg of water is quite accurate - maybe 0.001 out but that is not the current problem... Even on the bucket it says a 25kg bucket makes 750l water - I poured in 2.66 buckets.... That should not give 1.014.
Now I am really concerned since it does not make sense just to keep on dumping salt into the water until SG is right if I am adding too much - the rest of the salt must be somewhere?
Mr31415
Active member
Just another thought - to get from 1.000 (RO/DI water) to 1.010 I need a certain amount of salt x for a certain amount of water y.
To get from 1.010 to 1.020 do I need another x amount of salt or is it non-linear? If non-linear, would it be significantly less or more than x?
To get from 1.010 to 1.020 do I need another x amount of salt or is it non-linear? If non-linear, would it be significantly less or more than x?
Mr31415
Active member
bertoni - here are a couple of questions summarised that I'd greatly appreciate if you could answer them for me:
1) Why is my water cloudy? Is this Mg precipitate?
2) Considering the salt had been at temperature in the water mixing for 16 hours and still at 1.014 - can I assume it will NOT raise in the next couple of days?
3) If the answer to the above question is YES, where did the heavy ions go that would have raised the density of the water?
4) Is SG linear as per my previous post? I.e. to get from 1.000 to 1.010 takes the same amount of salt than to go from 1.010 to 1.020?
5) Lastly, what should I do now to get my salinity to 1.025? Should I siphon off a bucket (120l) of tank water @ 1.014 and mix it with salt outside the tank to say 1.040 with a powerhead, and once dissolved throw it back in the tank - repeating this until the tank is at 1.025?
1) Why is my water cloudy? Is this Mg precipitate?
2) Considering the salt had been at temperature in the water mixing for 16 hours and still at 1.014 - can I assume it will NOT raise in the next couple of days?
3) If the answer to the above question is YES, where did the heavy ions go that would have raised the density of the water?
4) Is SG linear as per my previous post? I.e. to get from 1.000 to 1.010 takes the same amount of salt than to go from 1.010 to 1.020?
5) Lastly, what should I do now to get my salinity to 1.025? Should I siphon off a bucket (120l) of tank water @ 1.014 and mix it with salt outside the tank to say 1.040 with a powerhead, and once dissolved throw it back in the tank - repeating this until the tank is at 1.025?
Mr31415
My 37.5 gms/L to make up a 35 salinity/1.0264 sg solution is consistent with an sg of 1.024 after adding 68 kg to 2000L. Is this consistent with what you see?
Getting to your questions about what is the cloudiness and where did all the salt go, can probable be answered by you.
Did you raise a sand storm during your mixing?
Have you measured alk, mg, ca yet?
My 37.5 gms/L to make up a 35 salinity/1.0264 sg solution is consistent with an sg of 1.024 after adding 68 kg to 2000L. Is this consistent with what you see?
Getting to your questions about what is the cloudiness and where did all the salt go, can probable be answered by you.
Did you raise a sand storm during your mixing?
Have you measured alk, mg, ca yet?
Mr31415
Active member
I was expecting about 1.024.
Since 6 hours ago I am draining 110l of water into a drum, obviously at the current tank SG which started at 1.014, then adding enough salt to raise it to about 1.058 (using a powerhead in there). Once stabalised I pump the solution back into the tank, then wait for it all to mix properly. Doing this I have managed to raise it to 1.019.
I have just tested the water. My tests from yesterday after just adding 68kg of salt directly to the tank:
SG - 1.014
Alk - 6dKH
I tested it again just now after having used above method twice (to raise it from 1.014 to 1.016 to 1.019:
SG - 1.0195
8dKH
452mg/L
1240mg/L
Which all seem fine to me. The only out of whack parameter was alkalinity which I tested before adding more pre-mixed salt, which was quite low.
Since 6 hours ago I am draining 110l of water into a drum, obviously at the current tank SG which started at 1.014, then adding enough salt to raise it to about 1.058 (using a powerhead in there). Once stabalised I pump the solution back into the tank, then wait for it all to mix properly. Doing this I have managed to raise it to 1.019.
I have just tested the water. My tests from yesterday after just adding 68kg of salt directly to the tank:
SG - 1.014
Alk - 6dKH
I tested it again just now after having used above method twice (to raise it from 1.014 to 1.016 to 1.019:
SG - 1.0195
8dKH
452mg/L
1240mg/L
Which all seem fine to me. The only out of whack parameter was alkalinity which I tested before adding more pre-mixed salt, which was quite low.
<<< The thing about the substrate and why I cannot believe there are any more undissolved salt is that it is a very fine sand so any coarse particulate matter will lay on top of it - >>>
How can you be certain of this? If the substrate is a fine sand it would blend in with any undissolved salt and make it hard to see I would think.
How can you be certain of this? If the substrate is a fine sand it would blend in with any undissolved salt and make it hard to see I would think.
Similar threads
