I Know This Should Be In Brackish(salt ?)

[fishfishfish]

how much salt do i need to make my 20 gal salty enough for fig 8s.

 

[SirMinion]

Moved.

 

[TammyLiz]

Judging by what nmonks told me recently, if you don't have a hydrometer, put in .65 oz per gallon of water. Then get a hydrometer and keep the salinity at 1.005. I'm just repeating what I was told. I just got a F8 last week so I'm new to this, too. HTH.

 

[JJ1234567]

the problem with this approach is that as time passes your salt will absorb water from the air, and change its weight. so .65 oz isnt enough salt before too long. Definitly get a hydrometer.

 

[TammyLiz]

Yes, I am planning on getting a hydrometer. I'm looking for one that isn't too expensive, but my trouble is that I can't find one that reads down to 1.005! So they're not going to do me any good. Does anyone know of a specific one that goes down that low? Hopefully not too much $$.

 

[ac106]

Yes, I am planning on getting a hydrometer. I'm looking for one that isn't too expensive, but my trouble is that I can't find one that reads down to 1.005! So they're not going to do me any good. Does anyone know of a specific one that goes down that low? Hopefully not too much $$.

Marineland/Instant Ocean has one, sold at every PetCo i have ever been too. It reads from 1.000 all the way up and sells from $9-$12 depending on the location and if its on sale.

 

[nmonks]

Just to clarify this, going by mass of salt per volume water is indeed only 100% reliable when the salt is dry. To keep the salt dry, you need to keep the package tightly sealed in, for example, a Tupperware or tin box, preferably with some silica gel. It also helps to store the salt away from sources of moisture (i.e., not in a kitchen or a damp garage). Even better, store it somewhere warm and dry, where the humidity will be lower than normal, for example in an airing cupboard.

Regardless, the salt will absorb some water from the air. How much, I don't know. But it will be "within the margin" as far as brackish water fish are concerned. No brackish water fish needs an exact specific gravity: by definition they are adapted to a range. If you take a figure-8 puffer, for example, with water changes to a 30 gallon tank you are going to get through a small box within a couple of months. Thus, the salt will still be relatively dry by the time you're done with it and onto a new box. Ergo, the error in estimating specific gravity by mass won't be enough to cause harm to the fish.

Nonetheless, getting a hydrometer is probably essential over the long term. I'd recommend going by mass of salt only a stop-gap solution until you find a hydrometer at your preferred price-point. It needn't be especially accurate for brackish water fish; as mentioned earlier, none of them care about the exact salinity, and all of them can tolerate much wider (and more sudden) changes in salinity than can marine fishes. You might even be able to find a cheap one in a store that sells brewing equipment.

As an aside, there is some good evidence that changing the salinity at each water change (within a certain margin) is therapeutic to brackish water fish. The only people who have spawned monos, for example, have done so by exposing them to high and then low salinities, or by exposing adults to freshwater conditions for long periods (i.e., months, not days). The idea that brackish water fish need constant salinity levels is entirely erroneous. The filter bacteria might, but not the fish.

Incidentally, I've known marine biologists who could judge salinity very accurately by taste.

Cheers,

Neale

Judging by what nmonks told me recently, if you don't have a hydrometer, put in .65 oz per gallon of water. Then get a hydrometer and keep the salinity at 1.005. I'm just repeating what I was told. I just got a F8 last week so I'm new to this, too. HTH.