Help on salinity

[howdydoo91]

Hi i'm new to reef2reef so i dont really know how tags work, but I do have a few questions, the biggest being how ro/di water works. Today I recieved an aquaticlife ro/di, and when I tested the hardness (my tap water is beyond unsafe due to it) in which it came out to 0 for the first time ever. After adding instant ocean salt I noticed the hardness increased by a lot within a few minutes, and I'm also having trouble getting my salinity higher than .20-.21 now. Is there something that may be going wrong?

 

[KStatefan]

Adding salt to RODI water will make it increase TDS/Hardness. TDS of sea water is 35,000 mg/l.

 

[DDenny]

That is good that your getting 0 TDS out of your RO/DI but like KStatefan said when you add salt the TDS will go up. For salinity shoot for 1.024-1.026 specific gravity or 34-35 ppt. How are you measuring your salinity? With a refractometer? As far as bringing up the salinity you just add a little salt at a time until you get to where you want it to me if it gets to high add a little RO/DI. Your using IO salt and that is what I use as well. I put a level 1/2 cup per gallon and that gets me close then I just add RO/DI until I get mine to 35ppt.

 

[howdydoo91]

That is good that your getting 0 TDS out of your RO/DI but like KStatefan said when you add salt the TDS will go up. For salinity shoot for 1.024-1.026 specific gravity or 34-35 ppt. How are you measuring your salinity? With a refractometer? As far as bringing up the salinity you just add a little salt at a time until you get to where you want it to me if it gets to high add a little RO/DI. Your using IO salt and that is what I use as well. I put a level 1/2 cup per gallon and that gets me close then I just add RO/DI until I get mine to 35ppt.

Yes i'm using a refractometer but when i measured the hardness it had skyrocketed on the first half cup of salt, is this normal? Or had i just measured my cup wrong at the time?

 

[Justanano]

So... not an emergency

 

[DDenny]

Yes i'm using a refractometer but when i measured the hardness it had skyrocketed on the first half cup of salt, is this normal? Or had i just measured my cup wrong at the time?

Yes the freshwater is going to shoot up quickly with the first tablespoon of salt. Just add salt into the freshwater until you get to the salinity you want for your tank.