Backyard Aquaponics
A place to discuss aquaponics

Does anyone see a problem with using the sun to distill seawater into water and salt and then using both parts in the system as required?
It won't be to completely take the place of other water (ie. rain or tap), but help supplement it. The salt would just be an added bonus if i could use that as well. And it would also have afew of the other trace elements as well. Altho there is always the possibility of contaminated seawater to start with as well.

Cheers
Jono

If you know your seawater is clean Jono... then there's no reason why you can't just add it as a top up... I do... about 50L every couple of weeks or so... into 1000L...

Seawater is high in trace elements and minerals...

Topping up all the time with straight sea water would probably cause the system to get too salty so if you are really short on water, you may still have to distill some for the water. It would definitely take less effort and energy to simply add regular sea water when you need the salt/trace minerals though. I guess you could maybe save the salt from the distilling process for cooking?

I too see no difference between adding sea water and adding pool salt.
just use ocean water over port or bay water
distilled water is afaik pure, so nomatter what the quality if you distil it will be fine.
Discarding the firstcqnd last bits will be helpfulnin keeping liquid solvents out of your distilled water.

Kuda is right on there, for the distilled water, that is pretty darn pure (provided whatever surface the water is condensing on, and collecting in, is good and clean.) However the salt and whatnot left over from questionable water would not be good to use.

I live at secret harbour, so there are constantly waves breaking there (well almost anyway ) so theoretically it should be fairly clean. The addition of just plain seawater and the saltiness is abit worrisome. Thats why i was thinking of distilling it and maybe using the salt as i would normal pool salt, but was kinda wonderin what else would be in there.
I spose i could get it tested initially (i have contacts ).
Does anyone know what, if any, purification that normal seasalt goes thru b4 its packaged for human consumption?

pool salt, which we use goes through the process of evaporation, this is all.
Eating salt is much different.
Don't use eating salt in your system
I would eat Pool salt.

The issue with eating salt is the anti-caking agents added. The NaCl itself is perfectly fine.

If the seawater looks nice and clear (no mucky harbor water etc) or you are eating shellfish out of it then I would say don't worry, go ahead and add it to your system at rate of 1 liter out of every 30 liters (to give you 1ppt of salt).

If the seawater is nice and clear and you don't know of any major sources of pollutants nearby, go ahead and use the salt. But no need to go all the way to dry salt: you may want to stop at about 90% as I think the brine may try to retain the water as it becomes more concentrated and hygroscopic.

Sea water is 35ppt I learnt yesterday.
You want your system between 1 and 3 ppt
as the plants take salt out of your water I wwould think to keep the salinity at 1 ppt you'd need to add water with salinity > 1ppt so perhaps if you distilled it to 2 or 3 ppt this would work better as topup and as hygro said, it'll be easier to distill to almost pure rather than tripple distilling to pure water.

I'm confused, KP. distilled water is 0ppm dissolved minerals, first time. Might have some volatiles, like alchohol (if that happened to be there. Not common in seawater, unfortunately. ). What remains (salts plus some water) is always going to be higher than 3ppt as you noted, more like 35ppt.

When we add salt, we dissolve it in some water and dump it in. Soooooo, seawater is equivalent to dissolving salt in water: dump in the right amt and all is good. Just a little more complex as one needs to decide how much salt to add, then figure how much water that is and add it. I would ignore the extra water added: we ain't that precise.

Undistilled salt water is 35ppm.
UPON INVESTIGATION YES, NO SALT WILL DISTILL OFF SORRY
Arrrgh! Damn Capslock!!!!!
so the left over will be very high concentrate. Equivalent to 35 + 35 * litres distilled / very salty litres ppt.

ie if you had 10 litres and you distilled off 6 litres, then you'd have 6 litres of pure water and 4 litres of 64.25ppt water (if water will hold that much, other wise there will be crystals on the bottom)

again, apologies for the misleading info.

So in theory i'll be able to use the salt like i would normal pool salt, (with the added bonus of some trace elements) and use the water to help top up the tank as well.
Would the salt be ok for cooking, or eating in general?
Just tryin to think of ways to use the excess salt that i'll prob have without throwing it out or putting it back in the ocean.

Yep, it would be just like using rock salt for cooking...

Should be fine for cooking/eating/fish. Flavor may be different from pure NaCl or store sea salt due to various minor constituents that are often left out (they precipitate earlier or later than the "sea salt" component).

Hey, how about giving extra to friends as gifts? Homemade sea salt!