puttting in my live rock today. Have question

[newbeeMike]

I am finally ready to put my live rock in my tank. But I have a question. I have a 45 gal tank that already has 60lbs of sand and saltwater in it. It has been fitering for about 2 weeks. I am going to be putting in about 75-80lbs of live rock today but noticed that the salinity in the tank was a little low. It is still in the target are of the hydometer but at the low end. There is nothing in the tank as of right now. Do I need to take out water and replace with new saltwater already mixed. Is there a formula to raise the salinity in a tank with saltwater already in it. Please I need some advice.

 

[Reefdaddy1]

First off let me say COngrats on putting your tank together. Secondly ...GET RID OF THE HYDROMETER!!. Get a refractometer. Its a cheap great investment. Every Hydrometer I have ever used has read differently compared to another. Take your water to your local LFS and have them test it. Then buy a refractometer. You will be thankfull for it.

 

[mmkeeper]

to raise your salinity in an excisting tank. You do a series of partial water changes with higher salinity replacement water. Get a refractormeter, the difference between my hydrometer was about .005.

 

[Reefdaddy1]

to raise your salinity in an excisting tank. You do a series of partial water changes with higher salinity replacement water. Get a refractormeter, the difference between my hydrometer was about .005.

Shoot MMkeeper I had a full point difference on mine, I was so happy with a Refractometer purchase I did a dance. Best investment I ever made in test equipment.

 

[NaH2O]

newbeeMike - what is the specific gravity or salinity of your tank right now? I can't forsee any issues when you add the new live rock, other than some potential die-off, which, IMO isn't a big deal since it sounds like you are still cycling? How is your ammonia, nitrites, nitrates? When adding that much live rock, even if the salinity wasn't an issue, I'd recommend checking for ammonia spikes if your tank was cycled already. Also, be sure when adding that much live rock you allow for good water flow around and through the rocks, so you don't get detritus collecting heavily in areas. It could lead to algae issues in the future.

I agree with what has been said for hydrometers. They aren't the most accurate, so there is a chance your salinity is higher or lower than what you think. I started off using a refractometer for my system, and I'm glad I did. I bought a hydrometer to use for my mixing water, and it was a pain trying to make sure the bubbles were off the swing arm, and it still wasn't as accurate as the refractometer. It is one of my "worth the money" purchases.

When raising salinity of a system, you want to do it slowly. I'll link you to a salinity adjustment calculator, and you have to use ppt not specific gravity (even though it says you can). To figure out what your salinity is (if you only know specific gravity), you can use this conversion calculator: Salinity Conversion. Here is the adjustment calculator for determining how to go about raising the salinity: Salty Zoo Salinity Adjustment Calculator. For example: 1.020 you are at a salinity of 26.6 ppt, and you want the salinity to be at 35 ppt (for a reef tank). Use those values, and enter in 1 as maximum ppt you will change. After you hit calculate, you can scroll down and see how many water changes are recommended, at how many gallons, and what salinity the water should be for the water changes.

You also want to make sure your pre-mixed water is the same temperature and pH as the main tank. It is good practice to get into early on, even if you aren't dealing with any livestock right now. There are pods, and possibly some other good hitchhikers in there that will appreciate it .

Hope this helps!

 

[alison]

If you can't get a refractometer yet, have your water tested every so often, and tap on the hydrometer to get rid of all the air bubbles.

 

[Scooterman]

In addition to Alison's post also rinse it well with ro water after or at least rinse it. You can get the refract later & tweak it while your still cycling anyways. BTW my deep six was very close to my huge floating hydrometer which is very accurate also.

 

[fulinn]

Help with a new Refractometer

Good Day !

After reading all the rec's for a refractometer, I have purchased one. However I have a question on its use, any help would be appreciated.

This is part of the instructions on how to calibrate the refractometer :

"...If the instrument is equipped with Automatic Temperature Compensation system (which it is), the ambient working temperature of the room must be 20 C ( 68 F ) whenever the instrument is recalibrated.."

Ok I'm lost. I need to calibrate it for the first time, how in the heck can I make the ambiet temperature of my livingroom 68 F ????

Thank you for any tips or suggestions for use of this instrument, I'm really looking forward to using it in place of the plastic hydrometer I currently have.

Bonnie

 

[liveforphysics]

For your application, or really any application where you arent trying to match the salinity of someone elses water who is useing a different refractometer, it wont make a bit of difference.

Also, I took Elmo18's advice and just re-labled my $5 specific gravity meaureing tool with the use of a quality refractometer. Obviously you need to be alert to bubbles and things, but it has the required precision. After my re-labeling, it has the accuracy to go with it.

I've made many compairisons after my re-lableing, and had it be dead on with other peoples refractometers.

And, just so you guys know, a refractometer is not the end all device for accuracy, they dont know what things in the water are changing the angle of refraction, so its still not a real measure of salinity, but rather a sort of disolved ion count sort of thing.

 

[Curtswearing]

I've made many compairisons after my re-lableing, and had it be dead on with other peoples refractometers.

I've owned many hydrometers. With each use without a good cleaning, they become less and less accurate. Not only do they need to be cleaned well, they need to be stored in a salt-spray, dust-free environment.

And, just so you guys know, a refractometer is not the end all device for accuracy, they dont know what things in the water are changing the angle of refraction, so its still not a real measure of salinity, but rather a sort of disolved ion count sort of thing.

No, but in terms of what most hobbiest's can afford, it's not only good, it's a heck of a lot better than most people's hydrometers. Most refract's are calibrated to standard Sodium Chloride. Therefore, when discussing NSW they are off a little bit. However, they are off a LOT less than most hydrometers unless they are brand new.

Everyone is entitled to their opinion. However, I disagree with your recommendation. If you can afford it, get a refractometer.

Whatever people choose, stability is key. A coral kept at a less than ideal SG consistently is usually happier than a coral that is occasionally at NSW conditions but sometimes above or sometimes below that SG.

 

[liveforphysics]

Thats right Curt, rinseing it before storeing it is important to maintain accuracy, much like wipeing off the lense of the refracto after each use. I just see that stuff as normal operateing procedure.

Both devices(when quality well made units) have the ability to be precisce. Both devices dont know if they are measureing sulfate, magnesium, etc rather than NaCl, however, none of that really matters.

If we had a clue like, this coral wants to be at 3x.xxx salinity or something, then getting the accuracy really narrowed down could matter. In reality, we dont have a clue what salinity that coral really wants, and on a natural reef, hi-tide to low-tide can cause pretty big swings on a daily basis, espically in winter.

I dont wana stir anything up here, refractos work really well, and its totally idiot proof. They are a great tool, and a good purchase.

 

[Skimmy]

i like using a tds meter to determine salinity, dirt cheap and vastly more acurate than a hydrometer, there is a conversion chart right here on RF.

 

[Boomer]

And, just so you guys know, a refractometer is not the end all device for accuracy, they dont know what things in the water are changing the angle of refraction, so its still not a real measure of salinity, but rather a sort of disolved ion count sort of thing


Livefor-buddy

Yes they are

Let me explain. There is no such device that really measures true salinity. Salinty is defined as the toal amount of all solid material dissolved in 1 kg of seawater, when all the carbonate has been converted to oxide, all the bromine and iodine is replaced by chlorine and all organic matter completly oxidized. The solid material, with no water, is expressed in grams, where salinity is given in g kg / l or ppt.

Lets look at a more migh-mouse version of it If you took a sample of seawater, that we know is 35 ppt and removed all the water you get 35 g kg / l by weight. This would give the following ion concentation by weight.

Cl- = 19.354

SO4-- = 2.712

Br- = 0.0673

F- = 0.0013

B = 0.0045

Na+ = 10.77

Mg++ = 1.290

Ca++ = .4121

K+ = .399

Sr++ = 0.0079

Total = 35 .00 g kg / l

This is something that takes a long time and is costly. Thus, there are 6 std measures that are use to replace this that are very accurate.

Chlorinity, where you measure the Cl- content which is 19 ppt for NSW. Chlorosity, which is the same but is expressed in g / l rather than in k kg / l. The Salinity can be mathamatically calculated for this by a constant, when using Chlorinity

S o/oo = 1.80655 x Clorintiy o/oo.

The other 4 stds are Refractometer, Electric Conductivity, Density and Specific gravity. The cuurent std is EC (Electric Conductivity) , which is the abiltiy for water to conduct electricity,

1. EC = 53,025 uS @ 77= 35 ppt

2. Density std @ 77F = 1.0237 =35 ppt

3. S.G = 1.02425. @ 77 using a std lab SG meter ( 59F) = 35 ppt

4. Refaction Idex, (RI) is 1.33940 @ 20C ( I do not have one for 77F). = 35 ppt

"IF" you took a std NSW sample, all of the meters/devices would give the above values but that is only NSW and we are NOT using NSW to calibrate things. If we where, we could use the same sample for all of these devices/meters to calibrate them. There are std. NSW solutions for this but they cost an arm and a leg :lol:

So, a refract is a std in seawater salinity measurement and they are very accurate, if calibrated correctly. Before EC it was the std.

A SeaTest Swing Arm is the best for anyone, if they know how to properly use it, clean it and get a good one. They are also not effected by temp. The problem with most swing arms, is that people blame the device and should be blaming themselvies. Out of all the swing arms that have been tested the SeaTest is the best. If my SeaTest sample reads 35 ppt and then I compare it to my $600 EC meter = 53mS = 35 ppt .....the same Usually a SeaTest reads a little low but so do many of the refracts, as they are calibrated to NaCl, which is not NSW. So, you need to "bump" the refract cal solution sample, to get it to read properly, meaning a NaCl solution % that is = to NSW RI @ 35 ppt. This is all explained in Randy's articles

Reef Aquarium Salinity: Homemade Calibration Standards
http://reefkeeping.com/issues/2004-06/rhf/index.htm

Using Conductivity to Measure Salinity
http://www.aquariumfish.com/aquariumfish/detail.aspx?aid=1804

Specific Gravity Measurement
http://www.advancedaquarist.com/issues/jan2002/chemistry.htm


Nikki

That SaltyZOO calculator is only good if the hydrometer is calibrated to the same temp as the sample water, otherwise it is off and needs to be temp corrected.....that is floating bulb type hydrometers. A Tropic Marine is very accurate.

Refract cailbration temp is best if it is the same as the sample water temp, less error. Those with ATC usually do not have an issue with temp but I would do it at tank temp anyway.

The other issue we have been fighting for years and it will just not go away, is " my salintiy is 1.026", That is NOT Salinity but SG. People should start to use ppt as in 35 ppt, 34 ppt etc. as Salinity.

 

[KRMNAL1]

And, just so you guys know, a refractometer is not the end all device for accuracy, they dont know what things in the water are changing the angle of refraction, so its still not a real measure of salinity, but rather a sort of disolved ion count sort of thing


Livefor-buddy

Yes they are

Let me explain. There is no such device that really measures true salinity. Salinty is defined as the toal amount of all solid material dissolved in 1 kg of seawater, when all the carbonate has been converted to oxide, all the bromine and iodine is replaced by chlorine and all organic matter completly oxidized. The solid material, with no water, is expressed in grams, where salinity is given in g kg / l or ppt.

Lets look at a more migh-mouse version of it If you took a sample of seawater, that we know is 35 ppt and removed all the water you get 35 g kg / l by weight. This would give the following ion concentation by weight.

Cl- = 19.354

SO4-- = 2.712

Br- = 0.0673

F- = 0.0013

B = 0.0045

Na+ = 10.77

Mg++ = 1.290

Ca++ = .4121

K+ = .399

Sr++ = 0.0079

Total = 35 .00 g kg / l

This is something that takes a long time and is costly. Thus, there are 6 std measures that are use to replace this that are very accurate.

Chlorinity, where you measure the Cl- content which is 19 ppt for NSW. Chlorosity, which is the same but is expressed in g / l rather than in k kg / l. The Salinity can be mathamatically calculated for this by a constant, when using Chlorinity

S o/oo = 1.80655 x Clorintiy o/oo.

The other 4 stds are Refractometer, Electric Conductivity, Density and Specific gravity. The cuurent std is EC (Electric Conductivity) , which is the abiltiy for water to conduct electricity,

1. EC = 53,025 uS @ 77= 35 ppt

2. Density std @ 77F = 1.0237 =35 ppt

3. S.G = 1.02425. @ 77 using a std lab SG meter ( 59F) = 35 ppt

4. Refaction Idex, (RI) is 1.33940 @ 20C ( I do not have one for 77F). = 35 ppt

"IF" you took a std NSW sample, all of the meters/devices would give the above values but that is only NSW and we are NOT using NSW to calibrate things. If we where, we could use the same sample for all of these devices/meters to calibrate them. There are std. NSW solutions for this but they cost an arm and a leg :lol:

So, a refract is a std in seawater salinity measurement and they are very accurate, if calibrated correctly. Before EC it was the std.

A SeaTest Swing Arm is the best for anyone, if they know how to properly use it, clean it and get a good one. They are also not effected by temp. The problem with most swing arms, is that people blame the device and should be blaming themselvies. Out of all the swing arms that have been tested the SeaTest is the best. If my SeaTest sample reads 35 ppt and then I compare it to my $600 EC meter = 53mS = 35 ppt .....the same Usually a SeaTest reads a little low but so do many of the refracts, as they are calibrated to NaCl, which is not NSW. So, you need to "bump" the refract cal solution sample, to get it to read properly, meaning a NaCl solution % that is = to NSW RI @ 35 ppt. This is all explained in Randy's articles

Reef Aquarium Salinity: Homemade Calibration Standards
http://reefkeeping.com/issues/2004-06/rhf/index.htm

Using Conductivity to Measure Salinity
http://www.aquariumfish.com/aquariumfish/detail.aspx?aid=1804

Specific Gravity Measurement
http://www.advancedaquarist.com/issues/jan2002/chemistry.htm


Nikki

That SaltyZOO calculator is only good if the hydrometer is calibrated to the same temp as the sample water, otherwise it is off and needs to be temp corrected.....that is floating bulb type hydrometers. A Tropic Marine is very accurate.

Refract cailbration temp is best if it is the same as the sample water temp, less error. Those with ATC usually do not have an issue with temp but I would do it at tank temp anyway.

The other issue we have been fighting for years and it will just not go away, is " my salintiy is 1.026", That is NOT Salinity but SG. People should start to use ppt as in 35 ppt, 34 ppt etc. as Salinity.

C'mon man lighten up !! the guy asked a question about raising the salinity in his NEW tank that he is cycling and you post this

 

[Scooterman]

A Tropic Marine is very accurate.

This is what I use because at the time It was all I could afford, it is big, bulky but comes with a nice padded case so I guell I'll just keep using it.

 

[fishermann]

What lighten up; Boomer was just rebutting a statement made here with facts that persoanably I am glad to know and have more articles to check out.

 

[Boomer]

C'mon man lighten up !! the guy asked a question about raising the salinity in his NEW tank that he is cycling and you post this

You need to re-read that, it is a post to Liveforphysics and Nikki, not Newbee. In which case, I was requested to come here and post this

 

[liveforphysics]

Thank you VERY much for the info Boomer. I really appreciate you taking the time, and I definately learned from your post.

Just from getting lucky, a SeaTest Swing Arm type is the same unit I use, and it just seemed like a no-brainer to flush the unit after I'm finished with it. Its always been very consistant for me.

Thanks again!
-Luke