SEA Alkalinity, 8 fl oz (237 mL)

SKU: A8253 | UPC: 015561182539
Format: 8 fl oz (237 mL)
Categories: , , ,

Fluval SEA Alkalinity is a concentrated, alkalinity-boosting supplement that provides an important energy source for supporting strong coral growth.

  • Raises and maintains alkalinity levels to support strong coral growth
  • Offsets ongoing alkalinity depletion caused by coral absorption, coralline algae and organic compounds
  • Helps maintain optimal pH levels
  • Contains USP (Pharmaceutical) grade sodium carbonate, sodium bicarbonate and sodium borate
  • Ultra pure and free of unwanted contaminates, gluconates, nitrates and phosphates
  • For use in saltwater aquariums
Dosing Instructions:
Add 10 mL per 50 L (13 US Gal) once a week. Weekly dosage provides 0.5 meq/L (25 mg/L) of alkalinity. Regular alkalinity supplementation is strongly recommended. Maintain alkalinity level between 2.5 to 4 meq/L (125 – 200 mg/L as CaCO3).
Note: It is recommended to maintain calcium at a range of
400 – 450 mg/L to ensure proper balance with alkalinity.
Always dose calcium and alkalinity supplements several hours apart.
SALTWATER ONLY2019-03-25T05:18:01-04:00



How do I get rid of visible waste on the live rock in my reef tank?

Install a polyester aquarium filter pad or floss in your filter, then direct the current of a circulation pump at the rocks and coral. This should help liberate the waste, which will in turn be collected in the filter. After 1-2 hours, remove the filter pad or floss and perform a water change.

I just boosted my aquarium’s alkalinity level and the water turned cloudy. Is the alkalinity supplement defective?

When dosing alkalinity supplements, you must be aware of your tank’s calcium level. If your calcium level is too high or low in relation to the alkalinity level, you will create precipitation, which can look like cloudy water. When dosing alkalinity, always consider the net volume of your tank. With larger quantities of live rock, deduct 20% of the aquarium volume when dosing alkalinity as a starting point, then adjust by testing and verifying the resulting KH value.

How do I control phosphate in a saltwater tank?

Cheatomorpha algae can grow abundantly when provided with strong lighting and can help eliminate these unwanted compounds naturally. Use a test kit to identify the source of the phosphates and address it directly.

Do Fluval SEA marine supplements have a specific shelf life?

Yes, there are specific expiry dates depending on the product. Iodine, for example, has a 2-year shelf life, while Trace Elements, Strontium and 3-Ions have 3-year shelf lives. Check the back of the label for the best before date.

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WATER CARE2019-03-08T07:24:36-04:00



I’ve been cycling my aquarium for several weeks and have a high level of nitrite. How can I eliminate it?

We recommend a double dose of Fluval Cycle Biological Enhancer after having performed 50% water changes. At this stage, one or two 50% water changes should dilute the nitrite sufficiently to ensure the bacteria introduced keeps the nitrite level down.

How frequently should I perform partial water changes?

We recommend performing partial water changes every week or two. When keeping aquariums with high stocking densities, more frequent water changes are required. Always make sure the replacement water is of the right temperature and conditioned with Fluval Aqua Plus Water Conditioner.

My aquarium often suffers from high phosphate levels and algae problems. What can I do?

Perform regular water changes and be sure to remove any excess food in the tank. Live plants can help control phosphate levels. Use a test kit to identify the source of the phosphates and address it directly.

Are there any issues performing a weekly 20% water change in a heavily-stocked tank?

No. Frequent water changes are called for when keeping aquariums with high stocking densities. Make sure the replacement water is of the right temperature and conditioned with Fluval Aqua Plus Water Conditioner.

Do you offer any water care products to help clear up a cloudy aquarium?

How do you cycle an aquarium?

How can I fix the most common aquarium water issues?

How do you prevent algae growth?

My aquarium water is cloudy. What are the various types of ways I can clear it?

My aquarium water is full of organic waste (dead leaves, fish excrement, uneaten food, etc.). How can I get rid of them?

I heard tap water can be harmful to fish. Is this true?

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