Question about water

[HighVoltage]

So tomorrow my booster pump is coming in because we have low pressure off the well. The question I have is how do you calculate the salt with the Life Rock taking up space? We put in 40 lbs of dry rock in the tank and will be adding fresh water from the RODI barrel. It’s a 75 gallon tank.
Do we start low and slow adding the salt?
We were told to mix the solution in the tank. Is this correct or should we mix it in the 32 gallon container then put it into the tank? Thanks for the help. We are new to this.

 

[JTP424]

You can mix it either in tank or out of the tank. WHEN YOU'RE FIRST SETTING UP!! Always mix prior to putting into tank after.
If you're worried about being correct in your salinity mix outside and pour in :)
(Or just calculate how much water your adding and add that appropriate amount of salt based on the manufacturer direction)

 

[KrisReef]

You need a calibrated hydrometer. Add salt to bring up the salinity to 1.026, or there about.

Generally, I like to mix my salt in a bucket, dissolving it by pouring the salt into a fish net and swirling the net about until the salt has dissolve, then mearsure to adjust to the target salinity. I prefer to do this outside the tank but it can be done in the main tank to start. Then making water changes or topping off evaporation is simply adding salt or RODI water to bring the salinity to the target.

There are many ways and methods, doing what is easiest for your situation and then keeping the salinity on target by adding salt or water is pretty straight forward. The obvious thing is that once the salt is dissolved, if you used too much salt, you have to remove salt water and add RODI to lower the mix, and then you will have extra dissloved salt to store or discard. By getting the mix correct before adding to the tank, once you have a running system avoids stress to fish and coral. The rocks won't mind.

 

[HighVoltage]

You need a calibrated hydrometer. Add salt to bring up the salinity to 1.026, or there about.

Generally, I like to mix my salt in a bucket, dissolving it by pouring the salt into a fish net and swirling the net about until the salt has dissolve, then mearsure to adjust to the target salinity. I prefer to do this outside the tank but it can be done in the main tank to start. Then making water changes or topping off evaporation is simply adding salt or RODI water to bring the salinity to the target.

There are many ways and methods, doing what is easiest for your situation and then keeping the salinity on target by adding salt or water is pretty straight forward. The obvious thing is that once the salt is dissolved, if you used too much salt, you have to remove salt water and add RODI to lower the mix, and then you will have extra dissloved salt to store or discard. By getting the mix correct before adding to the tank, once you have a running system avoids stress to fish and coral. The rocks won't mind.

Thanks for the reply. So just fill the tank and add salt slowly while watching our hydrometer? That sounds pretty simple.
I am just worried about the displacement with the dry rock figuring out how much water I put in and how much salt to add. Does the salt readings change pretty quickly or do you wait for a bit?

 

[Largeangels]

Add salt, wait, then check. It may take some time for the salt to completely dissolve and mix thoroughly.

I always mix in the barrel, then add.

 

[get-salty]

its a 75gal total vol ? sump?

if its only a 75gal total vol, this is what i would do and i think it is the simplest way - imo oc

with a 75gal with scapes and sand, you're looking at ~60gal water vol
so.. id mix up 60 gal of saltwater in a container and dump it in. if its not enough, mix a few more gallons.

 

[HighVoltage]

its a 75gal total vol ? sump?

if its only a 75gal total vol, this is what i would do and i think it is the simplest way - imo oc

with a 75gal with scapes and sand, you're looking at ~60gal water vol
so.. id mix up 60 gal of saltwater in a container and dump it in. if its not enough, mix a few more gallons.

Thanks for your reply. So if I’m making my water in a 32 gallon container,I just put 30 gallons in there and add salt for 30 gallons then do it again to get the salt where it needs to be with each transfer?

 

[HighVoltage]

Thanks for your reply. So if I’m making my water in a 32 gallon container,I just put 30 gallons in there and add salt for 30 gallons then do it again to get the salt where it needs to be with each transfer?

Sorry. It is a 75 gallon tank with HOB filters.

 

[Biokabe]

First: Take advantage of reef calculators to help out here. If you search for Hamza's Reef Salinity, you should come to an excellent collection of simple calculators to help with these exact type of situations. Bookmark them and come back to them whenever you need them.

Second: For your first fill ONLY, just put in the water until you reach your fill line, then add salt until you reach the desired salinity. It doesn't matter how much your rocks displace - you just fill until full, then add salt until it's salty enough.

Third: for future reference, you can actually use that salinity measurement to calculate how much your rocks displace. All you need is a gram-sensitive scale and your salt mix. When you're getting ready to add in your first batch of salt, weigh out 1 kilogram of salt (or convert to freedom units and do the equivalent). Add the salt to your tank, let it mix thoroughly, and then test the salinity. Since you know how much salt you added, you can then use a very simple calculation to give you a pretty good estimate of your actual water volume. If you're using that Tropic Marin hydrometer, you'll need to find a table to convert relative specific gravity into parts per thousand salinity, but that's straightforward. Once you have that, the actual calculation is:

1000 / current salinity reading = Liters in your tank. Then just, again, look up the conversion from liters to gallons, and you'll know what your actual water volume is. It won't be exact, but it should get you within a gallon or two. Even if you don't need it for future saltwater mixing (you don't) it's useful to know if you ever need to dose anything else.

You can also do this after the fact, but it's somewhat easier to do when your starting salinity is 0.

 

[Project1004]

You should be able to come up with exact amount of salt and exact amount of RODI to mix your solution to match every single time.

In my case, I mix 5Gal RODI with 1.7lbs of Aqua forest reef salt (same with Fritz salt. Ha). This gives me exactly 1.026 every time. So there was time I did upgrade to the tank and had to make 40Gal at once. I used exact same 5Gallon bucket to fill up the 45brute and added exact same amount of salt (1.7lbs x 8times). Mixing wise some prefer longer mixing and some shorter. I usually mix only for 2hrs. 40gallon was over night mixing.

 

[Bucrob]

I would mix in the barrel so you know its right then don't have to worry about it being wrong in the tank and needing to either add a TON of RODI or add a TON of salt.

 

[KrisReef]

https://www.reef2reef.com/threads/why-does-adding-salt-mix-increase-volume.741259/post-7734219