Seachem Reef Advantage Calcium
SKU: 82664873699

Seachem Reef Advantage Calcium

Sale price$133.20 Regular price$148.00
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Description

Seachem Reef Advantage CalciumSeachem Reef Advantage Calcium Seachem Reef Advantage Calcium is used to restore and maintain calcium levels in aquariums to support coral growth while also providing magnesium and strontium in proportionate amounts. Concentrated, powder ionic calcium Maintains magnesium and strontium Can be added directly to aquarium Seachem Reef Advantage Calcium is a non caustic (pH 8. 38. 6) optimized blend of ionic calcium designed to restore and maintain calcium

Seachem Reef Advantage Calcium

Seachem Reef Advantage Calcium is used to restore and maintain calcium levels in aquariums to support coral growth while also providing magnesium and strontium in proportionate amounts.

  • Concentrated, powder ionic calcium
  • Maintains magnesium and strontium
  • Can be added directly to aquarium

Seachem Reef Advantage Calcium is a non-caustic (pH 8.3–8.6) optimized blend of ionic calcium designed to restore and maintain calcium to levels found in natural seawater. Calcium and carbonates are essential to all coral growth. If either becomes deficient, coral growth will cease, followed by a rapid decline in coral health.

Reef Advantage Calcium™ also includes magnesium and strontium in amounts proportionate to typical utilization ratios (100:5:0.1, Ca:Mg:Sr). This allows one to maintain these two important elements while maintaining calcium. Unlike limewater (kalkwasser), Reef Advantage Calcium™ does not have a caustic pH and will not deplete magnesium. Used as directed, it will not deplete alkalinity.

Directions

BEGINNER: Use 5 g (1 level teaspoon) per 150 L (40 gallons) twice a week. Dissolve in at least 250 mL (1 cup*) of freshwater. Check calcium every 2 weeks and adjust amount or frequency accordingly.

ADVANCED: Check calcium level, then follow addition regimen above until calcium is adjusted to 380–420 mg/L. Each 5 g/150 L will raise calcium by about 12 mg/L. Quantity or frequency can be adjusted, but do not exceed 10 g/150L per day. Thereafter, use as required to maintain calcium.

EXPERT: After determining the calcium consumption rate, set up a continuous drip system. Use the following formula to determine how much to add to your top-off water: m=vc/400 (m=grams to add to top off water, v=volume of tank in liters, c=amount to raise calcium in mg/L). For example, if you want to raise calcium by 25 mg/L in a 200 liter tank, then you would add 200x25/400=12.5 g into the top-off water. [For reference: 1 gallon*=3.8 liters, 5 g=1 teaspoon*]. HINTS: If used with Reef Calcium™, it is not necessary to exceed 380 mg/L total calcium. Use Reef Status™: Calcium to measure calcium.

DO NOT OVERDOSE: Excess calcium may enhance the loss of carbonate alkalinity. Do not directly mix with any carbonate supplement. Best if calcium & carbonate additives are added on alternate days or at least 30 minutes apart.

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SKU: 82664873699

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LeeLee 44268
Lake Worth, US
★★★★★ 5
True to size
Size: 9.5, Color: Tusk
I want to start off by saying I ordered a 9 and 1/2 and these fit perfectly so they are true to size. They are fairly comfortable in the heel isn't too high but is wide so they're very stable to walk in. They look great and can be styled in a variety of ways I have worn them with jeans but also a nice sundress and it works both ways. I've been wearing these for several months and they've held up really well and still look great.
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Reviewed in the United States on April 18, 2026
M
Mom of Kids and Farm Animals
Port Orchard, US
★★★★★ 5
Daughter ranks it 5/5. I rank them 4/5 due to heel comfort.
Size: 8, Color: Black, Size: 8, Color: Black
My foot is 9.44 inches long which usually places me in a 7.5. For this chart, it suggested the size 8. It's a perfect fit. The back zipper is easy enough to use. You don't even really need to undo the top strap once you have it adjusted to your preferred spot. My foot is narrow to normal around the heel and I'm wider in the toe box. These heels accommodate that well. I have plenty of room around my toes. The toe strap isn't smashing down either. The shoes seems well-made. The straps do not have a threads hanging. There's no sloppy glue drips around the bed. The bottom is strong and the heel is solid. I'm not a huge fan of thicker/chunky heel looks usually. I like the skinner heel styles mostly but ... there's a big positive to the chunky heels. They're very easy to walk in. Great heels for non-formal occasions. The bottom is not slippery. The cushioning around the toes in very nice. My only complaint is that the cushioning by the heel feels inadequate- especially at this price. It feels like you're walking on a block of wood. For that reason, I gave them to my middle schooler. She's thrilled. She pranced around the house in them testing them out for herself. She adjusted well to walking in them and she finds them comfy.
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Reviewed in the United States on January 21, 2026
A
AmazonCustomer
San Leandro, US
★★★★★ 5
Lucky Brand womens Herrika
Size: 9, Color: Smoke Grey
These shoes are some of the comfiest heels I've ever worn! The heel actually has a nice height to it, but it's at a gentle slope that feels very comfortable. The heel itself is thicker, which makes it easier to walk, and I love the ankle strap for added security. The shoe's construction is solid, the materials are durable, and the zipper at the back of the ankle moves smoothly. I got the smoke grey color, which I think is really more of a lighter skin tone color, so I don't really agree with the name, but the color is accurately represented by the photos on the product page. This is a great neutral shoe that will pair with many different outfits. It's high quality and versatile, so I think it's well worth the cost. I love my new shoes!
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Reviewed in the United States on January 15, 2026
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ResqGaming
Lexington, US
★★★★★ 5
Well made, true to size, comfortable, and attractive looking!
Size: 12, Color: Black
Wife was wanting a new pair of heels for a work party she has coming up and I happened to see these and thought they strongly resembled what she was looking for so I got them as a surprise for her. They arrived a few days ago and she tried them on that night and wore them around the house and to work a couple times to see how she likes them. So far, she is extremely pleased with them! She said they fit perfect and she's had no issues with comfort wearing them all day for work. She really likes the wider heel as it gives her more stability. Her favorite thing so far though has been all the compliments/comments she's getting from the other ladies in her office about them.
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Reviewed in the United States on January 15, 2026
D
Dawn T
Los Angeles, US
★★★★★ 5
Secure and super comfortable.
Size: 9, Color: Black, Size: 9, Color: Black
Lucky Brand nailed it with these sandals. The craftsmanship of the leather is top notch. I love the look of the crossover straps, they add a chic touch to any outfit. The fit is fantastic, I ordered my usual size 9 and found them to be perfectly true to size. 
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Reviewed in the United States on January 16, 2026

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