"Reef aquarium" salinity, I don't understand!

Robert5335

Please help me understand the nuance regarding salinity. Savchuk writes: "at a temperature of 25°C, the density of seawater should be between 1.022-1.024 g/ml." According to Table 4, the relationship between salinity and the density of seawater in cases where temperature correction is not required (p. 23) shows that 1.022 g/ml = 30.1 ppt, while 1.024 g/ml = 32.4 ppt. This means that salinity should be between 30-32 ppt. However, the same section states: "in a reef aquarium, salinity is maintained between 33-35 ppt," and a level of 31-32 is considered "critical." Accordingly, 33 ppt = 1.024 g/ml and 35 ppt = 1.026 g/ml. This suggests that density should be between 1.024-1.026, not 1.022-1.024 as stated in the text. Furthermore, reefkeeping recommends a salinity of 35 ppt, which corresponds to sg = 1.026, aligning perfectly with the readings in Table 4. The worst part is that 1.024 in the Red Sea Hydrometer is already in the red zone, while 1.026 is the upper limit of the green zone in the Aqua Medic salimeter. Am I misreading something, or am I confused about the units of measurement?

David

It turns out that your green scale shows 1.020-1.024, which corresponds to the text in the book, but you are holding in the red zone 1.026. I don't understand this. Aqua Medic salimeter measures Specific Gravity. Red Sea Hydrometer also measures Specific Gravity. It doesn't open. :?

Ronald5720

There's no need to overthink the recalculations; just keep it around 1.024 and everything will be fine. In my aquarium, it ranges from 1.022 to 1.026, and everything is thriving. In my opinion, even going outside these limits for a short time doesn't cause harm. If you're unsure about your readings, visit someone with a successful marine setup and check.

Joseph2576

In my opinion, authors sometimes forget to specify the temperature, and for floating hydrometers without temperature compensation, this is important.

Meghan

Do not pay attention to the color of the scale - this scale is green only for fish, as Tetra recommends keeping a fish aquarium at a lower salinity than an aquarium with corals and fish, as stated on the Tetra salt bucket. So keep it at 1.0264 according to the Red Sea Hydrometer. The Aqua Medic salimeter, which is a hydrometer, measures density. Therefore, it should be kept at 1.0233 at 25 degrees. Here is the table.

Joshua9847

Thank you! The puzzle is solved. Throughout the text of the book, it talks about density, while the table refers to SG, which was misleading. I still need to figure out what Aqua Medic salimeter measures. I'll read the instructions in my spare time.

Adam4310

I measure with a float. When preparing the brine, I make it 1.024, although the upper scale is 1.026. I don't mix according to the upper scale because I leave a margin for evaporation.

Robert5335

The first thing I did when making the purchase was to ask them to throw the salimeter into my aquarium. They did that, double-checked the readings with a reference one, for which I am very grateful; everything matched. However, there were some nuances, and I decided to figure it out.

Debra6575

It seems I've figured it out. The Aqua Medic salimeter does measure Specific Gravity after all. From the official site: salimeter is a density meter (hydrometer) allowing easy measurement of the specific gravity of saltwater in aquaria. In theory, its readings should match those of the Red Sea Hydrometer and be between 1.024 and 1.026. Is that correct?