1.022 specific gravity isn't fine, correct?

[Crabs+Shrimps-69]

Nearly a week ago, I tested my salinity with a hydrometer, and it claimed the salinity was 1.022sg. However, my hermit crabs and snails (currently the only livestock) have all been fine and 1.022sg is actually in the range the hydrometer recommends!

I'm using the dymax hydrometer (https://mydymax.com/products/2-in-1-glass-hydrometer) and I turned the flow off before recording my results.

Am I miss reading the specific gravity?
Also for some reason 1.026sg isn't in the recommended range, it stops at 1.025sg.

 

[Randy Holmes-Farley Verified Community Expert]

Salinity is fairly forgiving, but I’d certainly raise it, if accurate. I recommend about 35 ppt, sg = 1.0264.

You can make a diy fluid to test your hydrometer. Be sure to use the hydrometer recipe.

https://www.reef2reef.com/ams/reef-aquarium-salinity-diy-calibration-standards.956/

 

[Tangdora]

If you’re a hydrometer fan you should look into the tropic Marin high precision hydrometer. It’s a little pricey but its range is only between 1.021 and 1.031 only. Also the reason I think those mini versions have the green that ends at 1.025 is because I think they designed to be read at the surface rather then at eye water level. Given how close the numbers are. I forget the actual scientific name of the effect but the water level at the meter spikes up a hair where it comes into contact with the meter itself that is not the true reading level. The little green marking may be compensating for this and just helping to give a quick good or bad indication.

Also in the past prior to switching to the topic Marin I used a similar mini meter and they were not the most accurate. As a test once I bought a second and the two reading were completly different . Had to buy a third just to decided which was more accurate and went with the one that was middle of the three reading as my trusted option.

 

[twentyleagues]

Anywhere from 1.021-1.023 is typically fine for fish and inverts, corals (yes I know corals are inverts but this is how I differentiate them) you would want it higher 1.024-1.026 as Randy said. I typically keep my reef at 1.025. Alk, calc. mag will be effected by sg the lower sg will have less of those elements typically.

 

[Randy Holmes-Farley Verified Community Expert]

. Given how close the numbers are. I forget the actual scientific name of the effect but the water level at the meter spikes up a hair where it comes into contact with the meter itself that is not the true reading level.

Meniscus is the term for the effect. :)

 

[Tangdora]

. Given how close the numbers are. I forget the actual scientific name of the effect but the water level at the meter spikes up a hair where it comes into contact with the meter itself that is not the true reading level.

Meniscus is the term for the effect. :)

That’s it’s. Was trying to search one of your old article for the name and could not find it lol.

 

[Crabs+Shrimps-69]

Salinity is fairly forgiving, but I’d certainly raise it, if accurate. I recommend about 35 ppt, sg = 1.0264.

You can make a diy fluid to test your hydrometer. Be sure to use the hydrometer recipe.

https://www.reef2reef.com/ams/reef-aquarium-salinity-diy-calibration-standards.956/

Thanks, I will try to finish reading the article today. It is a little long, but I know it contains quality information.

 

[Crabs+Shrimps-69]

If you’re a hydrometer fan you should look into the tropic Marin high precision hydrometer. It’s a little pricey but its range is only between 1.021 and 1.031 only. Also the reason I think those mini versions have the green that ends at 1.025 is because I think they designed to be read at the surface rather then at eye water level. Given how close the numbers are. I forget the actual scientific name of the effect but the water level at the meter spikes up a hair where it comes into contact with the meter itself that is not the true reading level. The little green marking may be compensating for this and just helping to give a quick good or bad indication.

Also in the past prior to switching to the topic Marin I used a similar mini meter and they were not the most accurate. As a test once I bought a second and the two reading were completly different . Had to buy a third just to decided which was more accurate and went with the one that was middle of the three reading as my trusted option.

I'll look into the tropics marin hydrometer, especially if my current one fails @Randy Holmes-Farley's test.
Hopefully I can find somewhere selling it locally.

 

[Crabs+Shrimps-69]

Anywhere from 1.021-1.023 is typically fine for fish and inverts, corals (yes I know corals are inverts but this is how I differentiate them) you would want it higher 1.024-1.026 as Randy said. I typically keep my reef at 1.025. Alk, calc. mag will be effected by sg the lower sg will have less of those elements typically.

That explains why my hermits and snails are fine.
I'm glad I waited before buying coral.

 

[Malum Argenteum]

tropic Marin high precision hydrometer. It’s a little pricey

I respectfully disagree with the last bit. This tool is the best value in the reefkeeping world. After using one for a while now, I'd pay three times the asking price, easy. The thing's amazing, and is also one of those basic physics tools that's so well designed that it is nearly a work of art.

 

[Tangdora]

I respectfully disagree with the last bit. This tool is the best value in the reefkeeping world. After using one for a while now, I'd pay three times the asking price, easy. The thing's amazing, and is also one of those basic physics tools that's so well designed that it is nearly a work of art.

While I don’t argue it’s accuracy unmatch. I don’t like speaking for people’s financial situations and why I tend simply talk with the assumption everyone is on a tight budget and let them decide it really is or not :)

 

[TheNative192]

Honestly depends on if you have an ATO and the size of tank as well. Evaporation can swing the salinity so I like to stick to around 1.024 or 1.025 so that way if there is some evaporation I am not spiking it up to 1.028 or higher. I also keep some corals around 1.023 for softies no problem but I would say 1.025 or 1.026 is ideal (with an ATO).

Also remember the smaller the tank the larger the salinity swing! So 15 Gallon cubes might really need an ATO if your trying to stick at 1.026

 

[Nor'easter Reefer]

+1 on the tropic marine high precision hydrometer. I have a milwaukee digital refractometer, a manual, and the hydrometer, I almost always use the hydrometer.

 

[Malum Argenteum]

While I don’t argue it’s accuracy unmatch. I don’t like speaking for people’s financial situations and why I tend simply talk with the assumption everyone is on a tight budget and let them decide it really is or not :)

Fair enough, but having an absolutely reliable way to measure SG helps keep the financial situation good. I killed some stuff with a refractometer calibrated by a commercial solution that was off before spending the smartest $40 of my reefkeeping career.

 

[Ziggy17]

I respectfully disagree with the last bit. This tool is the best value in the reefkeeping world. After using one for a while now, I'd pay three times the asking price, easy. The thing's amazing, and is also one of those basic physics tools that's so well designed that it is nearly a work of art.

100% agree.

 

[Crabs+Shrimps-69]

Honestly depends on if you have an ATO and the size of tank as well. Evaporation can swing the salinity so I like to stick to around 1.024 or 1.025 so that way if there is some evaporation I am not spiking it up to 1.028 or higher. I also keep some corals around 1.023 for softies no problem but I would say 1.025 or 1.026 is ideal (with an ATO).

Also remember the smaller the tank the larger the salinity swing! So 15 Gallon cubes might really need an ATO if your trying to stick at 1.026

It's a 21 gallon tank, no ATO but a clear perspex lid (I've obviously taken it off to encourage evaporation), which significantly reduces evaporation.

Good to know soft coral can handle 1.023sg, at least based off your experience.

 

[TheNative192]

Honestly depends on if you have an ATO and the size of tank as well. Evaporation can swing the salinity so I like to stick to around 1.024 or 1.025 so that way if there is some evaporation I am not spiking it up to 1.028 or higher. I also keep some corals around 1.023 for softies no problem but I would say 1.025 or 1.026 is ideal (with an ATO).

Also remember the smaller the tank the larger the salinity swing! So 15 Gallon cubes might really need an ATO if your trying to stick at 1.026

It's a 21 gallon tank, no ATO but a clear perspex lid (I've obviously taken it off to encourage evaporation), which significantly reduces evaporation.

Good to know soft coral can handle 1.023sg, at least based off your experience.

It may not be bad to go to 1.024 as well. The key though is to always make changes slightly. I would recommend a Gravity ATO (usually like 20 dollars on Amazon) as they do not hold a lot of volume but keep the water level steady. Makes it easier than just adding RODI water and then you can stick to one salinity level.

Also if you have a skimmer just remember it can reduce the salinity! One super helpful tool to calculate salinity is this website they have a ton of different calculators as well adding salt replacing water etc

https://www.hamzasreef.com/Contents/Calculators/DirectSaltCalculator.php

 

[Crabs+Shrimps-69]

It may not be bad to go to 1.024 as well. The key though is to always make changes slightly. I would recommend a Gravity ATO (usually like 20 dollars on Amazon) as they do not hold a lot of volume but keep the water level steady. Makes it easier than just adding RODI water and then you can stick to one salinity level.

Also if you have a skimmer just remember it can reduce the salinity! One super helpful tool to calculate salinity is this website they have a ton of different calculators as well adding salt replacing water etc

https://www.hamzasreef.com/Contents/Calculators/DirectSaltCalculator.php

I didn't realise ATOs get that cheap!
My lid keeps evaporation down so much I still don't think I'm going to purchase it, but now if I change my mind I know what to look for!

No skimmer on my tank (or any mechanical filtration so far).

 

[Crabs+Shrimps-69]

Update:
Water has evaporated a little and the test I did earlier today gave a result of 1.023sg!

 

[Reefering1]

Get a ato!