[DanioToxicologist]

Hello Everyone,

I'm an honours student working towards completing several projects in aquatic heavy metal neurotoxicology using zebrafish embryos (no older than 48 hpf).

Because my strengths, and the strengths of my lab members, are in the life sciences, I'm having trouble figuring out how to reconstitute water according to OECD / International Organization for Standardization guidelines.

Hoping that you can help. One issue that I'm having is interpreting the units in the instructions, in the case of IS/L does the I stand for electric current, and the S for Siemans? L is obviously liters.

Help interpreting the notes below, and pointers on how to reconstitute water would be greatly appreciated.

Best,
-R

...

The artificial water corresponded to reconstituted water according to ISO 7346/3 (ISO 1996).

Conductivity: 700 lS/L

NO -3 : <4.5 lg/L
Nitrate

NO -2 : <8 lg/L
Nitrite

NH + 4 : <1.9 lg/L
Ammonia

PO4 - 3 : <50 lg/L
Phosphate

Fe2+ and Fe3+ not detectable.

Chemical oxygen demand (COD): < 4 mg/L

Diluted 1:5 using double-distilled water.

Before use, the pH was adjusted to 7.8 ± 0.2.
Muriatic (hydrochloric) acid can be used to reduce pH in aquaria.
The addition of bicarbonate of soda (baking soda) will also raise the pH and has the added benefit of buffering the water, used in aquaria.