Aquarium Salt and Evaporation mistake

**learis** · 02-17-2013, 09:54 PM

Hello, I made a boo-boo with my first aquarium. I have a 10 gallon and I've been replacing 2/12 gallons of water weekly. Since there's evaporation, I usually take out around 2 gallons and just add a fresh batch of 2 1/2 gallons of water and this tops off the tank. I add aquarium salt each replacement. However I have not taken into account that evaporation only evaporates water and not salt, so I'm pretty sure the salinity of my aquarium has increased.

I think I've been doing this for roughly 4 months, so I'm not sure how much I've screwed up the salinity. All the fish and plants are still ok.

What I did to try and correct this was to just do a 2 1/2 gallon water replacement without adding any salt this time. From now on, I figure I'll top off the tank with only water the day before I replace the water. That way, I can replace exactly 2 1/2 gallons and add aquarium salt without throwing off the salinity.

Is there something else I should do to make sure everything is ok?

**Cliff** · 02-17-2013, 10:01 PM

Is this for a marine tank ?

**learis** · 02-17-2013, 10:11 PM

No it's a freshwater tank. I use API Aquarium salt. It says add 1 rounded tablespoon for every 5 gallons, so I add 1/2 a tablespoon for my 2 1/2 gallon water changes.

**Cliff** · 02-17-2013, 10:16 PM

If you are worried that you have now added too much salt, you can always do a few very large water changes ( like four 50% water changes over 4 days) to make sure you have removed all the old water and salt. That will give you a fresh start and you can make sure you are maintaining a correct level from here on in.

You had meantioned salinity levels, are you testing that for your tank ?

**learis** · 02-17-2013, 10:41 PM

No i haven't tested salinity levels; I was just speaking in the general sense. I know that salinity is extremely low in a freshwater tank compared to salt water. Is there an actual tester that can read freshwater salinity levels and tell you what the recommended level is?

**Cliff** · 02-17-2013, 10:46 PM

LOL, I was about to ask you the same questions

I know refactormeters will read as low as 0.001 specific gravity, but I really do not know what a target level for FW would be. Prehaps the manufacture of the salt that you are using would have that info

If you are are following the instructions on the package you should not have worry at all. I was just curious so I thought I would ask

**mizzoutank** · 02-17-2013, 10:47 PM

Originally Posted by learis

Is there an actual tester that can read freshwater salinity levels and tell you what the recommended level is?

Freshwater is called freshwater because it doesn't involve salt.
no fish in a freshwater set up needs salt.

salt is only used in FW set ups for helping with treating for disease.

if you want a brackish tank. then that is a different story and different fish.

otherwise, there is 0 need for any salt in your set up.
so do a few massive water changes back to back and get to a normal natural level of near 0 salt in a freshwater set up.

**Cliff** · 02-17-2013, 10:55 PM

The use of salt in a fresh water tank (other than use as a treatment) can be debated, and has many many times here. You might find the below link interesting

http://www.aquaticcommunity.com/aqua...ad.php?t=31554

**dmagerl** · 02-18-2013, 12:15 AM

I think your math is wrong.

The tank size is 10gal, evaporation is .5gal, water change is 2 gal.

Evaporation will increase the salt concentration 10/9.5 = 105%

When you do the water change you are changing 2/9.5 = 21% of the water.

Thus, you are removing 21/105 = 20% of the salt.

This is exactly the same amount if there were no evaporation 10/2 = 20%.

So there's no reason to make any changes to your routine.

But I'm with the others, there's no need to add salt in the first place unless you want a brackish tank or are treating disease.

**talldutchie** · 02-18-2013, 06:24 AM

Originally Posted by learis

No it's a freshwater tank. I use API Aquarium salt. It says add 1 rounded tablespoon for every 5 gallons, so I add 1/2 a tablespoon for my 2 1/2 gallon water changes.

So what you've done basically is adding salt because someone at the shop said you'd better do it and now you have a brackish tank?
My advice would be to stick to your water changing regimen and stop that silly habit. This way your tank will gently revert back to freshwater gain.

Freshwater fish and ordinary tap water... there really is no need for that salt.