[bmward64]

Recently my LFS closed down, along with their livestock tanks, they had four tanks of various size set up that they used solely for display. One of the was a 46 gallon tall with a back back filter and a hang on back power filter that was about two years old. I bought the whole thing, water, sand, lr, filters, tank, stand, light, and heater. I also bought a deep 6 hyprometer to of course test the salinity, but it seems that it varies all the time when I test it, and when I mixed my first batch of salt water, it was perfect, 1.024, but when I went to do the water change a two days later it was at the low end of the spectrum, to low... What happened?

[gimmito]

Hydrometers or swing arms are not very consistent. You can test 10 times and get 10 different meetings.

I would invest in a good refractometer or a digital salinity meter (pinpoint, hanna, and milwakee are good brands). Checkout ebay or craigslist for deals.

[bmward64]

Would there be one at any LFS's

[gimmito]

LFS's usually don't keep them (at least mine don't).

Try these places and look for sales:

Aquarium supplies for your tropical fish tank, saltwater fish tank, saltwater aquarium fish, freshwater aquarium fish & reef aquarium. Aquarium filters, aquarium lighting, aquarium tanks, protein skimmers & more for your reef tank.

Pet Solutions

Aquarium Supplies, Pet Supplies and Pond Supplies by That Fish Place - That Pet Place

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[DEWAYNE]

sometimes you salinity levels will vary, don't know why? but I can test my 110g. at diff. depths and get diff. readings, seems like the salt will be higher at a deeper depth, but you are testing a smaller tank, not sure why? your readings are not the same. I will agree that digital is the way to go.

[pogodzib]

Hydrometers are usually consistent as long as the salt is fully mixed and aged, you test the water at the same temp. every time, and you make sure that there isn't bubbles on the swing arm. If you are getting different readings, more than likely one of the previously mentioned reasons is usually the cause. With that said, the readings that the hydrometer is giving you probably isn't accurate. From what I have found over the years, hydrometers are generally up to 0.005 ppm off. Get a good refractometer, that has automatic temperature compensation (ATC) and you'll know that you're getting an accurate reading every time (if calibrated properly).

[bmward64]

Thanks for the help guys!!!!!! I know its not bubbles on the swing arm (unless I am blind ) I don't know about the temp. though it should be the same because I have a heater in the tank so... anyway, I really appreciate the help.