New tank full of RO/DI (add salt?)

[Danzig]

I have a new tank, got my rock in, sand in and full of RO/DI about 75%. This is a 72 gallon bowfront. Im going to hold off on filling more until i add salt so i am able to mix etc. Is this correct? Also, i have a refractometer ive never used it before, it came with calibration fluid. Im going to read up on that in the package, ive never opened it lol. I have red sea coral pro salt, enough for 150 gallons. Im wondering what my next step should be. Should i heat the water and put in powerheads and when its 75ish degrees add salt? I just dont want to add salt thats not going to dissolve. Any tips would be greatly appreciated guys thanks.

by the way: i have a 20 gallon sump with a skimmer/pump/refugium which i just plumed down from my bulkhead, waiting to fill that because the pvc is drying, plus i want to be able to mix the salt in the DT, then top off with RO/DI until the system is fully funtioning then prob gonna check salinity and add more salt thats needed i think.

[disc1]

I'm looking into my crystal ball and I see everything coated in white.

You don't really want to mix in the tank, and you certainly don't want to do that at an increased salinity and then dilute it down.

If you need to mix salt in the tank for your initial fill, then get all the water in and circulating and then add the salt very slowly. Whatever you do, don't just dump it all in at once.

[Metal Man 1221]

I wouldn't add salt yet. You may want to let your PVC finish curing for 24hrs and then run the system without salt to test for leaks.

As far as adding salt goes. When your plumbing passes your leak test, get a heater in and get the water temp up to 76-78 (what ever your going to run it at) before you add any salt. Having your water pre-heated will aid in dissolving.

When adding salt do it SLOWLY. Adding salt too quickly will cause the pH of the water to spike and will result in a lot of calcium carbonate precipitant, hence disc1's comment about every thing coated in white. Add a little bit at a time and if you notice undissolved salt settling at the bottom, stop, and give it some time to dissolve.

[Danzig]

ok thanks guys that was very helpful. I will wait for the pvc to cure, that was my goal. If i fill it up and get it running on RO/DI, should i expect the water level to rise after i add salt? Even if i do it slowly as mentioned above? I have a feeling getting my salinity to 1.026 is going to be a huge PITA.

[Jandree22]

should i expect the water level to rise after i add salt? Even if i do it slowly as mentioned above? I have a feeling getting my salinity to 1.026 is going to be a huge PITA.
Yes the water level will rise subtly. Just take your time, scooping a few dozen cupfuls of salt into a high flow area of your system water probably won't be the end of the world. Nothing good ever happens fast in a reef tank :)

[96p993]

Once you have enough water running through the entire system add the salt to the sump and let it dissolve there. The salt will dissolve with the flow from DT and do it at its own pace. Dont run your skimmer during this time

[Mrs. Music]

This isn't live rock and live sand, right?

[Gandolfe]

You should have mixed the water before you added the rock and sand! If you add to much salt it could coat your rock and sand and kill off any bacteria already there, if you are using live rock and sand before added salt then you didn't read enough before starting your tank, you will kill off almost any bacteria and live things before you add salt by using freshwater!

[Metal Man 1221]

Totally missed the rock and sand!

+1 you should have had water mixed before adding these. Unless they weren't live, in which case carry on.

[Playa-1]

I wouldn't mix the salt in the tank with rock and sand in there.

[D-Nak]

I'm assuming its dead rock like BRS or Marco, and not live sand rather dry sand from a bag. If that is the case, then I don't see a the problem mixing the salt in the tank with everything else already in it.

I would just add the powerheads and heater to the tank and go for it. Once the salt is mixed then add enough water to start the flow to the sump.

If it's live rock and live sand, then you'll going to have to start over if it was sitting in RO water.

[zigzag1]

You don't need to heat the water to disolve the salt. Actually, you are more likely to precipitate the calcium and alkalinity in warmer water. Think about the first places calcium builds up in your system - on heaters and impellers - warm areas. While the salt will be slower to disolve in cooler water, there are advantages to mixing before heating. JMTC & GL!

[tkeracer619]

Wait till the thing is running so you know you don't have to drain. Then add salt. Do it slowly. It won't take long at all.

[Metal Man 1221]

You don't need to heat the water to disolve the salt. Actually, you are more likely to precipitate the calcium and alkalinity in warmer water. Think about the first places calcium builds up in your system - on heaters and impellers - warm areas. While the salt will be slower to disolve in cooler water, there are advantages to mixing before heating. JMTC & GL!

As long as the salt is mixed slowly there will be no precipitation. I have never experienced increased CaCO3 precipitation in warmer water, in fact I have experienced the complete opposite.