why isnt my salt dissolving

Are you putting salt directly into the display tank?

 

the hydrometer is important because while you can get a good guess of it making salt, water will evaporate out of the tank and that water must be replaced with fresh water, a small bit of salt will also evaporate, which is insignificant so its not replaced with top offs. over time it can make a bit of difference. also theres water changes.

its easy to see how over a period of time you salinity can change pretty fast especially in a small tank.

and of course theres always a chance you could miscount while making the salt

 

I would get a refractometer and not a hydrometer, as hydrometer's can be notoriously inaccurate.
Secondly, what are you doing for flow in the tank? I know you said you had a HOB filter, but what about actual flow? You're going to need power heads before you put anything in there, if you don't have them already. If you don't have them, that's why the salt is not dissolving, as it wont dilute into the water if the water is stagnant.

 

I have read that Red Sea salts tend to not dissolve fast. If your SG readings are normal, then I would just chalk it up to slow dissolving salts. If your SG is too high, cut back on the amount of salt you are using when you are mixing your water.
To mix your salts, you should have your fresh RO/DI water in a separate bucket, then pour the salt into that and stir it until it dissolves. Have a small powerhead in the bucket to keep the water circulating for the next 24 hours until the water stabilizes before you add it into your tank.

 

Mixing salt

A bucket+power head+heater IMO is a must. Power head to mix it and a heater to help dissolve it faster and so you can add to DT right after the 24hrs..

Also if you use tap water you must add tap water conditioner and wait 24hrs before adding the salt water to your DT.

If you use RO water IMO you must add trace elements.

Good luck,
Mike

 

A two foot tank could conceivably hold 45,000 liters or perhaps even more--if it has no bottom.

 

that wouldnt be a tank, that would be an abyss. lol

 

and as much as I respect reef sparkys contirbutions on the site

I do think his definition of "Hold" is somewhat questionable

Steve

 

. . . .

 

Just calculated how big the tank would need to be to hold 45000 litres with a length of 2 feet: 24" x 12" x 8836" (length x width x depth) thats 2ft x 1ft x 736.3ft! So yeah I agree with reefsparky it could be done but would be rediculus lol