- All water barrels have their volumes stamped on the top of the rim by the manufacturer.
- All barrels are labeled to indicate which species and which tanks they are to be used for.
- Sodium bicarbonate is used in water prep to increase the buffering capacity of the DI water, which will help the water maintain the pH and alkalinity.
- Calcium chloride is used to adjust hardness to the desired reading.
- All barrels are given an aerator at time of makeup.
- All barrels are given heaters set at the desired temperature as indicated below.
Note: There are separate water barrels, 55-gallon tanks for filtering the tap water, and pumps to move the water from the 55-gallon tanks to the barrels, for each researcher.
- Fill the 55-gallon tank with cold tap water (hot often comes out browner).
- Add Amquel as per instructions on bottle (1 capful/10gal).
- Add NovAqua as per instructions on bottle (1 capful/10gal).
- Add Proper pH 7.0 as per instructions on bottle (1 scoop/10gal).
- Let the water filter for several hours and then pump it into one of the barrels.
- Filters need to be cleaned approximately once a month.
- Fill the barrel with DI water.
- Add instant ocean sea salt to achieve a reading of 1.021–1.023 on the refractometer or 30–32ppt on the YSI, depending on the intended use.
- This usually takes about 6–7 cups of salt.
- The aging zebrafish are kept at 26C, so change-water should be kept at this temperature.
- All other zebrafish are kept at 28.5C, so change-water should also be at this temperature.
- There are different water barrels for the zebrafish to allow for these two temperature differences as well as a separate barrel for the Z-rack (see Rack Top-Off Water below).
- Fill the barrel with DI water.
- Add sodium bicarbonate to adjust the buffering capacity or carbonate hardness to ~120ppm. For a 40-gallon barrel, this takes approximately 10 grams of sodium bicarbonate. Also add nine grams of instant ocean sea salt. Let this mix for at least 30 minutes.
- Next, use calcium chloride to adjust the hardness to ~25–75. This takes approximately three grams of calcium chloride.
- Wait at least 24 hours before use.
- Test the pH before use. It should be 7.0–7.4.
Rack Top-Off Water
- Fill the 20-gallon tank with DI water.
- Add four grams of sodium bicarbonate. Let sit for 30 minutes.
- Add 1.5 grams of calcium chloride.
- Again, wait 24 hours before testing for pH (7.0–7.4) and using.
Note: Freshwater aquarium salt is added directly to the goldfish tanks after a water change, rather than adding it to the premixed water in the barrel.
- Fill a 30-gallon barrel with DI water.
- Add sodium bicarbonate to achieve a carbonate hardness of ~120ppm. This takes about 19 grams of sodium bicarbonate. Let sit at least 30 minutes.
- Next, use sodium biphosphate to lower the pH to ~7.2–7.6. This requires ~25 grams. Note: If pH is tested immediately, the reading will be much lower. Let the water sit ~24 hours and the pH will rebound some and stabilize at ~7.2–7.6.
- Test pH before use to be sure it’s 7.2–7.6.
- If tank pH is not maintaining, the amounts of sodium bicarbonate and sodium biphosphate may need to be adjusted. Also, the pH of the change-water may need to be adjusted down closer to the pH of the tank until that can be brought back up, so that the fish are not shocked during a water change.
If a 40-gallon barrel is used:
- Fill barrel with DI water.
- Add ~25 grams of sodium bicarbonate. Let sit ~30 minutes.
- Add 35 grams of sodium biphosphate.
- Test pH before use.
Note: The cichlids that we had were African from Lake Malawi, so when adding the cichlid lake salts, make sure to use the amount for the right lake.
- Fill 30-gallon barrel with tap water from horseshoe crab room.
- Add Amquel and NovAqua per instruction on the bottles.
- Add 16.5 grams of cichlid lake salts.
- Add six grams of sodium bicarbonate.
- Add three grams of calcium chloride.
Cichlid Top-Off Water
Note: Do not add cichlid lake salts.
- Fill 20-gallon barrel with tap water from horseshoe crab room.
- Add Amquel and NovAqua.
- Add 4.5 grams of sodium bicarbonate.
- Add one gram of calcium chloride.