Help With Adding Salt...

[neilw_uk]

Hi,

I need some advice for adding salt to my tank.

I have some Res Sea salt and need to know how much to add to increase the sg by .002. I have a 2g bucket which i can use to dissolve the water.

I have my refractometer (i need to get some distilled water to configure it), do i test the water in the bucket first or do i dissolve the salt and then test the tank or both?

Any advice would help as the bag only gives info for a full marine setup.

Cheers,

Neil

 

[andywg]

Every time you do a water change, add some water at the desired SG. At this rate you will gradually take the SG up more than slow enough for any filter bacteria to cope.

You can speed it up by putting in the water change water at a higher SG (say 1.004) to bring the SG up. I would say to test the water before going in, and then afterwards to check the tank. The next few times you are changing water, check the tank first to try and get some idea of how much you need.

One thing I am unsure of, and would readily defer to Nmonks, is that a raise from 1.000 to 1.002 is small enough for most filter bacteria to cope with it in one go. Most brackish fish can more than handle this. In these circumstances you may be able to work out how much salt is needed for the whole tank and then dissolve all that into your water change water (creating a hypersaline bucket). Once this is poured in the SG would level out.

But don't try the "all in one" without first checking with someone more experienced than I in changing SG.

 

[nmonks]

I wrote a little (Mac and Windows) computer program called Brack Calc that answers the first part of your question. It's free, so go ahead and download a copy. Then drag the slider across to where you want it, and it'll give you an (approximate) reading on how much salt to add per litre. SG 1.002 is, for example, about 12% normal seawater and contains about 4 grammes of salt per litre. So, if your tank contains 100 litres, you will need to use around 40 grammes of salt to turn the freshwater into brackish water at SG 1.002.

andywg is right about SG and filter bacteria. The cut off point is above 1.005, where the freshwater filter bacteria begin to be replaced with salt water ones. It doesn't happen suddenly, and it is usually possible, if you do things slowly, to adapt the filter over a couple of months from freshwater to marine without seeing a serious spike in nitrites or ammonium.

At SG 1.002, the filter bacteria won't care less, so you can add your brackish water at this salinity straightaway. SG 1.002 is, ecologically, still freshwater.

Cheers,

Neale

 

[neilw_uk]

Thanks for the tool.

Looks like i need 3g per L to make .002.

One question...

If i am trying to raise the tank by .002 how do i work it out? If i have a bucket that has 9L and i add 3g per L to bring this bucket to .002 then when i add this to my tank it will dilute. This is not too much of a problem, but when i do water change i am going to need to add more salt (more than 3g per L) as i would have taken some out.

Sorry for the dumb questions, but i dont want to get this wrong.


Thanks,


Neil

(oh, BTW the link to the FAQ's in the program is down)

 

[nmonks]

Sounds about right. There are ~35 grammes of salt per litre of seawater, which is an SG of ~1.024. Or, about 1.46 grammes of salt per 0.001 on the SG scale. The little program does these calculations depending on which slider you drag and how far, so there is a bit of variation. For brackish water fish, an error of 10 or 20% won't make any difference at all. Either way, the result is an estimate; you'll still need to use a hydrometer to confirm.

OK. If you need 3 grammes of salt per litre, and you have a 9 litre bucket, that's 9x3=27 grammes per bucket of water. Empty the tank by 25-50% and add the new water. Yes, when you do it next time, you will "waste" some salt, but this is the easiest way to raise the salinity.

The alternative, if you know the volume of the aquarium, is to add a more concentrated salt solution gradually over a couple of hours. Say you have a 100 litre aquarium, 100x3=300 so you would need to add 300 grammes of salt. You could dissolve this amount in your bucket of water quite easily (normal seawater has 35 grammes per litre, or 315 grammes per 9 litres). This concentration will probably take a good 20 minutes to dissolve, and if in doubt, leave it for longer, either for an hour with an airstone bubbling, over overnight just sitting there.

Once you're done, remove a bucketful of water, and then add the concentrated salt solution (in fact, almost normal seawater) about a litre at a time, making sure it mixes well (i.e., pour it into the tank by the filter, so it is "squirted" across the aquarium nicely). Wait 10-20 minutes, and then add another litre of the nearly-seawater. As you add the water, keep testing the SG using your refractometer or hydrometer to see how things are going. Keep an eye on your fish. If you have brackish water species, they will be looking decidely "perky" at the first taste of salt water!

Not sure why the FAQ link in the program doesn't work, it does for me. Admittedly, it goes to a redirect page, but still, it should work. If not, go here:

http/homepage.mac.com/nmonks/aquaria/brackfaqpart1.html

Cheers,

Neale

Looks like i need 3g per L to make .002.

If i am trying to raise the tank by .002 how do i work it out? If i have a bucket that has 9L and i add 3g per L to bring this bucket to .002 then when i add this to my tank it will dilute. This is not too much of a problem, but when i do water change i am going to need to add more salt (more than 3g per L) as i would have taken some out.

(oh, BTW the link to the FAQ's in the program is down)

 

[neilw_uk]

That has really helped me!! Thank you.

I have a 155L tank, so i will need 465g of salt to raise my tank. Adding 1L at a time is a good idea as not to burn my puffers I guess.

I have an air pump, but need an air stone for it.. i will grab one today and get to work.