• The mysteries of the work of marine salt buffers. Discussion needed.

  • Wendy2244

Dear marine aquarium enthusiasts, especially those with knowledge of hydrochemistry. When choosing salt for the aquarium (I am comparing several brands, so it will also be a mini-review), I encountered the following phenomenon: KH (in our case, alkalinity)/pH in freshly mixed water (one hour after mixing) and KH/pH in water that has been aerated according to the instructions (!!) from the manufacturers - differ significantly in some brands. For example, the picture and the result of "maturing" the water over three days. Moreover, I measured it multiple times, which is confusing based on dogmatic assertions. The solution density is 1.024, T=24°C, water - osmolality, TDS=3 (since there were many samples, all 3-5 liters, I slightly overloaded the column). The first 6 hours - abundant aeration. Then - 6 hours a day. The "aging" - three days (scale X). The second picture - even sediment formed. But the salt itself is mediocre... I initially had no illusions... But here is the fact. I am actually asking for ideas on the origin of such an effect. This phenomenon occurs in 50% of the salts considered, from cheap to quite reputable brands with a global name.

Anne4851

There are some thoughts about carbon dioxide in the air and its interaction with Ca and Mg ions... but. In the foamers, the aeration is so intense that it's unbelievable, and the pH in aquariums doesn't drop that much.

Rachel9060

81 views - and not a single thought?

Helen

The speed of water mixing also affects the pH when preparing water. For water changes in my aquarium, I prepare 30 liters of water, two buckets of 15 liters each, and the water is prepared for about 12 hours, using osmosis plus resin, with TDS less than 3. In one bucket, I mix the water with a pump rated at 3000 liters/hour, and in the other, a pump rated at 5000 liters/hour. In the bucket with the 5000 liters/hour pump, the pH value is always one to two tenths higher (depending on the salt). This effect was observed with Tetra salts, Aquarium Systems Instant Ocean, and Aquarium Systems Reef Crystals.

Brenda

Due to more intense mixing, the water is better enriched with oxygen. That's why the pH is slightly higher.

Leonard

Here, all conditions are the same. Even the shape of the container. TDS is less than 1. One device is used. The temperature is within 1 degree Celsius. The effect is present in all 8 brands of salts, but these three are the most pronounced.

Cassandra1840

When sodium bicarbonate dissolves, dissociation occurs according to the following equations: NaHCO3 = Na+ + HCO3- HCO3- = H+ + CO3-- The decomposition of the bicarbonate ion decreases pK The formation of H+ ions lowers the pH This will continue until the dissociation constant is reached.