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My Tank Thread
Sodium hydroxide is the strongest pH-raising alkalinity additive possible for reef tanks. It has the same pH boost as kalkwasser when raising alkalinity, but sodium hydroxide can be made more concentrated for two-part dosing. There are some dos and don'ts that one should know prior to starting and handling hydroxide.
1. Sodium hydroxide is highly caustic. Its extremely high pH can cause severe skin damage with prolonged contact. Always wear goggles to protect your eyes from accidental splashes, which can be especially dangerous. Protective gloves are also strongly recommended when handling it.
2. Sodium hydroxide will feel slippery when in contact with skin. If your hand ever feels this sensation, rinse thoroughly with running tap water.
3. Keep out of reach from children and pets. If the cabinet is easily accessible to young children, it may be worth reconsidering this additive or adding some cabinet locks to prevent unauthorized access to the solution.
4. Use food-grade sodium hydroxide, commonly available online or Amazon.
5. Don't use sodium hydroxide to maintain pH, as it will cause the alkalinity to rise too high. This happens because the pH-boosting effect is temporary as carbon dioxide re-enters the aquarium, but the alk addition is not (at least not until coral consumption).
6. Sodium hydroxide should be used in conjunction with a two or three part. Only using sodium hydroxide without the corresponding calcium and magnesium parts will result in those dropping over time. This is the most ideal, complete recipe for sodium hydroxide dosing: DIY Balling Method Recipe
7. Polyethylene or polypropylene containers are best to mix and store sodium hydroxide. High density polyethylene (HDPE) is what's used for most vinegar jugs sold, and that's what I repurpose for my sodium hydroxide containers. Additionally, the dosing line should be polyethylene or polypropylene. RO/DI tubing is also polyethylene, for example. Amazon sells polyethylene tubing in various diameters.
8. Sodium hydroxide creates an exothermic reaction upon dissolving in water. The solution gets very hot, and glass containers can amplify this. Borosilicate glass is one of the most heat resistant glass and should be used if selecting glass materials for dissolving and mixing the solution.
9. Be cautious and methodical when making sodium hydroxide stock solutions. Here are two tutorials/methods I’ve written on how to safely accomplish this:
Safely and Easily Mixing Sodium Hydroxide: A Step-by-Step Guide
How I Mix Sodium Hydroxide
10. Ensure the dosing pump can tolerate high pH solutions. The 1.1 mL/min BRS dosing pumps work perfectly with sodium hydroxide, as it is made from santoprene, which is resistant to caustic solutions. My BRS dosing pump is lasting years with constant exposure to sodium hydroxide. There may be other pumps that are adequate, but research the materials prior to purchasing.
11. Dose slowly in a high-flow area. The localized pH will be very high upon dosing, and this can lead to precipitation issues if not rapidly mixed in. If the dosing area has very mild flow, adding a wave maker will be crucial.
12. Keep dosing lines above water. If left in the water, the solution will precipitate and clog the tubing with crust.
13. Spread the dose. Dosing large volumes will cause the pH to spike too high. It's best to space out the dose throughout the day, night, or 24 period.
14. Offset the calcium and hydroxide doses because adding both at the same time near each other significantly increases the likelihood of precipitating calcium carbonate, wasting the solutions. I like to offset my dosing pumps by 30 minutes.
15. For the best pH boost possible, only use hydroxide for the entire alkalinity demand. Partially using AFR, for example, and the remaining with hydroxide will not lead to the same pH boost as only using hydroxide for the entirety of the alkalinity demand.
I may add more tips as they come along. :)
1. Sodium hydroxide is highly caustic. Its extremely high pH can cause severe skin damage with prolonged contact. Always wear goggles to protect your eyes from accidental splashes, which can be especially dangerous. Protective gloves are also strongly recommended when handling it.
2. Sodium hydroxide will feel slippery when in contact with skin. If your hand ever feels this sensation, rinse thoroughly with running tap water.
3. Keep out of reach from children and pets. If the cabinet is easily accessible to young children, it may be worth reconsidering this additive or adding some cabinet locks to prevent unauthorized access to the solution.
4. Use food-grade sodium hydroxide, commonly available online or Amazon.
5. Don't use sodium hydroxide to maintain pH, as it will cause the alkalinity to rise too high. This happens because the pH-boosting effect is temporary as carbon dioxide re-enters the aquarium, but the alk addition is not (at least not until coral consumption).
6. Sodium hydroxide should be used in conjunction with a two or three part. Only using sodium hydroxide without the corresponding calcium and magnesium parts will result in those dropping over time. This is the most ideal, complete recipe for sodium hydroxide dosing: DIY Balling Method Recipe
7. Polyethylene or polypropylene containers are best to mix and store sodium hydroxide. High density polyethylene (HDPE) is what's used for most vinegar jugs sold, and that's what I repurpose for my sodium hydroxide containers. Additionally, the dosing line should be polyethylene or polypropylene. RO/DI tubing is also polyethylene, for example. Amazon sells polyethylene tubing in various diameters.
8. Sodium hydroxide creates an exothermic reaction upon dissolving in water. The solution gets very hot, and glass containers can amplify this. Borosilicate glass is one of the most heat resistant glass and should be used if selecting glass materials for dissolving and mixing the solution.
9. Be cautious and methodical when making sodium hydroxide stock solutions. Here are two tutorials/methods I’ve written on how to safely accomplish this:
Safely and Easily Mixing Sodium Hydroxide: A Step-by-Step Guide
How I Mix Sodium Hydroxide
10. Ensure the dosing pump can tolerate high pH solutions. The 1.1 mL/min BRS dosing pumps work perfectly with sodium hydroxide, as it is made from santoprene, which is resistant to caustic solutions. My BRS dosing pump is lasting years with constant exposure to sodium hydroxide. There may be other pumps that are adequate, but research the materials prior to purchasing.
11. Dose slowly in a high-flow area. The localized pH will be very high upon dosing, and this can lead to precipitation issues if not rapidly mixed in. If the dosing area has very mild flow, adding a wave maker will be crucial.
12. Keep dosing lines above water. If left in the water, the solution will precipitate and clog the tubing with crust.
13. Spread the dose. Dosing large volumes will cause the pH to spike too high. It's best to space out the dose throughout the day, night, or 24 period.
14. Offset the calcium and hydroxide doses because adding both at the same time near each other significantly increases the likelihood of precipitating calcium carbonate, wasting the solutions. I like to offset my dosing pumps by 30 minutes.
15. For the best pH boost possible, only use hydroxide for the entire alkalinity demand. Partially using AFR, for example, and the remaining with hydroxide will not lead to the same pH boost as only using hydroxide for the entirety of the alkalinity demand.
I may add more tips as they come along. :)
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