Store bought Saltwater salinity low?

[MohrReefs]

Hello everyone, first time post here. We just got a 44g Pentagon tank and we put dry rock and sand in. We have yet to cycle it. My hydrometer (Aquarium Solutions plastic hang in the tank type) says the salinity is between 1.021 and 1.022. Is this too low? Is this just a cheap hydrometer? Are these not accurate?

It's the same water they use in the LFS store tanks and the fish seem fine and healthy there. But online says it should be higher, especially if I want corals in the future.

TYIA!

 

[SmallLebowski]

Yes that is a little low. The hydrometer may be to blais as you suggest. Maybe ask the LFS to test the source water to confirm?

 

[Auquanut]

Welcome to R2R! If you got your water from the LFS, chances are that your hydrometer is correct. Often the store will maintain their tanks at around 1.021 to minimize parasite/disease manifestation in their fish only sales tanks. I would definitely ask. I like to keep mine at 1.026 for corals.

 

[MohrReefs]

Welcome to R2R! If you got your water from the LFS, chances are that your hydrometer is correct. Often the store will maintain their tanks at around 1.021 to minimize parasite/disease manifestation in their fish only sales tanks. I would definitely ask. I like to keep mine at 1.026 for corals.

Thanks Auquanut! If that's the case, will I regularly need to add salt to the LFS water in order to have corals or fish? I'll give them a call!

 

[MohrReefs]

Welcome to R2R! If you got your water from the LFS, chances are that your hydrometer is correct. Often the store will maintain their tanks at around 1.021 to minimize parasite/disease manifestation in their fish only sales tanks. I would definitely ask. I like to keep mine at 1.026 for corals.

Talked to the store, they actually said they keep theirs at 1.025. Somethings not right. Either this is a bunk tester or a bad mix of saltwater.

 

[Auquanut]

Talked to the store, they actually said they keep theirs at 1.025. Somethings not right. Either this is a bunk tester or a bad mix of saltwater.

Either one is very possible. When I went from a hydrometer to a refractometer, I found the hydrometer was reading about .003 low.

 

[splitting_lanes]

I think some LFS keep salinity low because it saves money on salt.

its 20% cheaper to make 1.020 than it is to make 1.025

my $.02

 

[W1ngz]

Time to break free of the LFS and start making your own water with something more accurate than a plastic hydrometer.

 

[Saltyreef]

Is this bulk seawater from a holding tank or sealed brand jugs?

 

[vetteguy53081]

They tend to run low (hypo salinity) for disease prevention. Yes, you will have to add salt to increase prior to introduction of new water.
Start with half cup and see what it does. Keep track of what you add for desired salinity and you will know what to add in the future

 

[YankeeTankee]

Invest in a refractometer. BRS has a good one, I like the slightly cheaper one (not the LED).

You may also have caught your LFS owner saving some cash on salt mix, if they advertise higher, but we can't be sure without something better than a hydrometer, so I guess we will give him the benefit of the doubt.

 

[Saltyreef]

The only time id ever trust a hydrometer is if it was a floating bulb. Swing arms are only accurate when theyve been checked and corrected against a refractometer or floating bulb hydrometer.

 

[MohrReefs]

Thanks everyone. I bought a refactometer and will test again. If it turns out that it's under with the more accurate tester I will avoid that store and just make my own.

 

[MohrReefs]

Is this bulk seawater from a holding tank or sealed brand jugs?

Jugs from the LFS

 

[MohrReefs]

Invest in a refractometer. BRS has a good one, I like the slightly cheaper one (not the LED).

You may also have caught your LFS owner saving some cash on salt mix, if they advertise higher, but we can't be sure without something better than a hydrometer, so I guess we will give him the benefit of the doubt.

That would be really disappointing.

 

[DMG Reef]

I think if your LFS says the water is 1.025, then it is. I doubt they would try to save a little money by making the SG lower when most reefers test the salinity before doing a water change. Wouldn't be a sustainable method of increasing their revenue by a few dollars. If the LFS runs their fish displays at a lower salinity, they probably just add RODI to adjust.

 

[MohrReefs]

I think if your LFS says the water is 1.025, then it is. I doubt they would try to save a little money by making the SG lower when most reefers test the salinity before doing a water change. Wouldn't be a sustainable method of increasing their revenue by a few dollars. If the LFS runs their fish displays at a lower salinity, they probably just add RODI to adjust.

You have a good point, I bought a refractometer so I'll double check before doing anything. They are highly rated so I doubt it is a cutting corners thing and I'm leaning towards bad equipment.

 

[Saltyreef]

Jugs from the LFS

So if they are sealed jugs, the brand they are sold under should divulge the SG of the water.

 

[MohrReefs]

So if they are sealed jugs, the brand they are sold under should divulge the SG of the water.

These are jugs they sell and fill themselves, no labels unfortunately.

 

[Saltyreef]

These are jugs they sell and fill themselves, no labels unfortunately.

I see. So its from a bulk holding tank then...

As mentioned above just check it against a refractometer and youll be fine.
If the LFS is using a calibrated refractometer it must be the correct salinity.

Fwiw my old swing arm hydrometer read 1.025 when my water was actually 1.031.
I would advise to make a new mark on the swing arm gauge where 1.025 really is so you can continue to use it accurately. And it will NEVER need calibration again. Your refractometer will collect dust soon after lol.