Posted by: Me | May 25, 2006

Specific Gravity

I tested the specific gravity of the new batch of water last night. Despite using way more salt than recommended and aerating for two days. I got a specific gravity reading of only 1.021—with both hydrometers. (I find it weird that they are now suddenly always in agreement –or close.)

Bit the bullet and tested the water in the tank.

Red Sea hydrometer: 1.017 Deep Six: 1.015

Topped off the tank with the prepared salt water. Retested. No measurable change. I’m going to leave the cover off the tank then retest when the level’s dropped significantly. Then I’ll top off with the 1.021 salt water and use this procedure to work the numbers up from there.

I don’t understand why I have so much trouble making up water with higher specific gravities. It seems like in the past several months I’ve had to add more and more salt. I know it’s not totally dissolving, but I don’t know why. Maybe I should leave the jug of salt water on the windowseat with the cap off, let some of it evaporate. (No, I won’t do that; it would introduce yet another uncontrolled variable into the plan.)

Posted in First Attempt

« working on the water
topped off tank »

Responses

Hi mate, what brand salt are you using to make up batches for water change? Are you heating the water up to temp when adding salt?
SG is relevant to the temp of the water. Just an idea as to why you may have trouble dissolving all the salt and get odd readings.

JT

By: JT on May 27, 2006
at 3:47 am

I’m about halfway through the big box oif Instant Ocean I bought in the fall. It’s getting so hard I have to almost chisel it out of the box. I live near the coast, so humidity is high. Can salt mix “go bad” after a long period of time…or as an effect of humidity? I swear the salt was dissolving better when I first bought it.

By: Me on May 27, 2006
at 6:04 am

It is my understanding that salt can “go bad” if not stored correctly ie. in none moist or humid conditions. It will last pretty much indefinatley if stored correctly.
If you are having doubts, my advice is to purchase a new box of salt.

JT

By: JT on May 27, 2006
at 5:41 pm

It seems wasteful to buy new salt, but that’s what I fear I will have to do. If buying new salt solves the problem of it not dissolving properly, it still doesn’t solve the problem of the salt going bad. :-(

I live near the Texas coast in an extremely humid, sub-tropical climate. Storing the salt mix so that it isn’t exposed to humidity is a problem. Just opening the box and pouring it into a plastic container it will be exposed to humid air! ;-) And again and again every time I open the container to make up more water.

Transferring the salt to an air-tight container as soon as I open it, will probably extend the usability of the mix compared to this box. Thanks for your help, JT. :-) BTW, I’ve added you to my blogroll. Nice site! :-D

By: Me on June 10, 2006
at 7:26 am

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