adding salt

I just test my salt level and found that it is below were I want it. My question is when you increase the salt level should this be done very slowly, like over a month or can I do this in a shorter time like a week?

How the tank is currently inhabited ? What is the current salnity and what is the desired one ?

Very small difference you can cover over night... Larger ones, especially when the tank is populated with delicate animals, need to be performed over longer time...

Hey,

I am no pro - still fairly new to this but from what I have learned/been told, do not change it more than 1 point a day ie... 1.023-1.024 or 1.025 to 1.024. This would of course depend on what you have in there. I had ( ) a starfish and he would get really cranky on a half a point a day. With him in there I would do a point over about 3 days (this does not include top-ups for evaporation). He didn't seem to mind that to much. All my other stuff in there, polyps, Hammer coral, inverts, clowns etc... don't seem terribly bothered by a point jump over the period of a day (drop it a few ticks every few hours...).

S.

I add 2-3 litres a day of RO water to compensate for evaporation. I figure if you added a similar volume of double concentrated salted water to whatever your daily evap volume is, the delta will be the same (albeit in the opposite direction) so that's going to be safe. I guess this might take a while if you need to bump up the salinity dramatically but if things are stable, that shouldn't be a problem.

Hmmm. I have a green brittle star and he never seemed to be bothered by much of anything, much less by a salinity change of 0.001.

Not all starfish are the same. Linkia species are known to be more sensitive to salnity variations than other stars...

I wasn't aware of that. Actually Brittle stars are closer to Crinoids than they are to starfish. And unlike most starfish, can move across a tank relatively fast if properly motivated. They have eye lenses made of calcium carbonate that are apparently considered perfect lenses for use in fiber optics (when I first got mine, I was amazed at how sensitve they were to light and movement near the tank. When I come close to the tank, if it is out of the rocks, it usually hides rather quickly). There is a research program with them (I believe at the Univerity of Maryland) to see if the lenses can be made synthetically.

Nevertheless, they are indeed much hardier than many starfish, and nearly all crinoids (which is why you don't see live crinoids at pet shops). I've had mine for nearly ten years, and it is now about 18' across the longest arms. It once ate an entire dying long tentacled anemone. The result was that it developed a large hole completely through it's body (I assume as a result of the stinging cells of the anemone), and over a period of several months, it completely healed itself. They have an incredible immune system, which is being studied for possible medical breakthroughs with the human immune system.

Hey,

I agree it does not seem like much, but my Red Linkia would 'run' when the water came in. If I went with more of a top up, the ends of each arm would curl up. In the end, somthing got a piece of him, he lost a leg and had battle scars all over... until he (?) eventually died. With what I have in there now, I can drop it two to three points (does not happen to often) and all that will happen is my clowns look a little irritated, and my Hammer Coral will pull in a little. I believe that a small top up will not only decrease salinity, but changes other things like trace elements, nitrates (good thing though on this) etc... all this for some things living in tanks might be even a little stressful. Not saying that salinity can't be dropped more at once safely, just not comfortably!

S.

If you are having these problems, I suggest that perhaps you are pouring maku up water in too quickly. Try doing it more slowly, over a longer period of time. I never add water directly to the tank. I always mix it very slowly in the sump. As for changing the chemistry, you have to remember this: although the salinity will change, the relative concentrations of salts do not change. Absolute concentrations DO change, however. In other words, if, for instance, you have a one gallon solution containing 20% calcium and 0.1% sodium, adding a pint of pure water to the solution will not change the concentration of one salt relative to the other. You will still have the same amount of calcium relative to sodium. However, the total concentration of the solution will be reduced because you've diluted the solution. This is the same for just about any dissolved solid.

I personally would just top up with mixed saltwater instead of freshwater until i was at the desired salinity. This pretty much ensure that it'll be done over a longer period of time, and helps give you a little more control over it so you don't 'over do' it and end up with it to high.

I don't know if I really consider it a problem per-se, but going more slowly on top-ups is definitly a god idea. All I started doing was doing top ups twice a day. I understand what you are saying about chemistry and absolute concentrations, I was refering more to all the extra stuff in the tap water. I am sure this would change the overall chemistry over a period of only top-ups. You say you mix water in slowly in your sump, I would do that if I had one! I have a pretty basic setup (skimmer, tank, lights, heater, fish.) and do add directly to my tank. I have a sort of glass 'stopper' that I pour the water on and it disperses from there-usually in the jet's stream which spreads it around.