Red Sea Coral Pro Sea Salts - 7 kg (210 Ltr) Bucket

• 11.5-12.5 dKH straight out of the bucket - enough carbonate headroom that a growing reef does not sag between water changes.
• Calcium 450-480 mg/L, magnesium 1350-1430 mg/L - raised in step with the alkalinity, so the three foundation elements stay balanced instead of one running ahead.
• Potassium 385-415 mg/L - brackets Red Sea's 400 ppm reef target, so water changes alone hold the level.
• Makes 210 litres - the practical size for systems under about 300 litres, where a 22 kg bucket would sit open for months.
• Resealable bucket - salt is hygroscopic (it draws moisture from the air), and a sealed lid is what keeps the last scoop mixing like the first.
• Dissolves clear in about 20 minutes - Red Sea's reformulated blend, so a water change is not an overnight job.
• $0.32 per litre mixed - the highest cost per litre in the Coral Pro range; the premium buys a size that will not sit half-used for months on a smaller system.

All three packs are the same formula. Choose on how fast you get through it, because opened salt takes up moisture and clumps.

As a rule, buy the pack you will finish within about three months of opening it.

1. Start with RO or RO/DI water brought to tank temperature, around 25 degrees C.
2. Add salt to water, never water to salt, with a powerhead already running.
3. Add roughly 1 kg per 30 litres, then check and adjust.
4. Circulate and aerate until the water is completely clear - normally about 20 minutes.
5. Match temperature and salinity to the display before the water goes in.

Mix to your refractometer, not to the box. The 1 kg per 30 litre figure is Red Sea's pack rating; the exact dose that lands on 35 ppt varies with your source water and your measuring method.

Use mixed saltwater within about 24 hours. Left standing, alkalinity drifts down and carbonate can precipitate out on the bottom of the drum.

Suitable for

• Mixed reefs, LPS and soft coral systems in an active growth phase
• Frag tanks and coral grow-out systems
• New reef tanks still building coral mass
• Reefers who want water changes alone to hold foundation levels

Not suitable for

• Freshwater aquariums of any kind - this is a full synthetic seawater mix, not a tonic salt
• Mature SPS systems already running at 7-8 dKH; a jump to 12 dKH at a water change can burn tips. Red Sea Salt at 7.7-8.2 dKH is the match there
• Topping up evaporation - always top up with fresh RO water, never with saltwater
• Marine fish-only systems, where the elevated foundation levels are simply not consumed

Keep the lid sealed and the bucket up off a concrete garage floor. Salt draws moisture and sets hard, and while a clumped bucket still works, the amount of salt per scoop changes - weigh it rather than scoop it if it has gone solid.

A 7 kg bucket opened and used within about three months will still mix clear at the bottom.

• Red Sea Seawater Refractometer - sets your actual salinity, since the pack rating is only a starting point.
• Red Sea Salt Measuring Cup - keeps scoops consistent between mixes.
• Red Sea Reef Foundation Pro Multi Test Kit - confirms the calcium, alkalinity and magnesium you actually landed on.
• Coral Pro Salt 22 kg bucket - the step up when 210 litres stops lasting the month.
• Red Sea Coral Colours Pro Test Kit - for the iodine, potassium and iron that water changes alone will not hold.

As a consumable, salt carries no service warranty, but it is covered by the consumer guarantees under Australian Consumer Law. If a bucket arrives damaged, contaminated or will not dissolve, we replace it.

At 7 kg this ships as a standard parcel. Check the seal on arrival - a split bucket that has taken moisture in transit is worth reporting before you mix it.

How much water does a 7 kg bucket of Coral Pro Salt make?

A 7 kg bucket of Red Sea Coral Pro Salt makes 210 litres of seawater at 35 ppt, which is Red Sea's pack rating of 1 kg per 30 litres. The exact dose needed to hit 35 ppt varies slightly with source water, so set the final salinity with a refractometer rather than by weight alone.

What is the difference between Coral Pro Salt and standard Red Sea Salt?

Coral Pro Salt mixes to 11.5-12.5 dKH with calcium at 450-480 mg/L, while standard Red Sea Salt mixes to 7.7-8.2 dKH with calcium at 415-445 mg/L. Coral Pro is aimed at reefs actively building skeleton; standard Red Sea Salt suits mature systems already held at natural seawater alkalinity.

Can I use Coral Pro Salt in a fish-only marine tank?

It is safe in a fish-only marine tank, but the elevated calcium, magnesium and carbonate exist to build coral skeleton and go unused without corals. Standard Red Sea Salt is the more sensible choice for fish-only and FOWLR systems.

Why did my alkalinity read lower than 12 dKH after mixing?

Freshly mixed saltwater loses alkalinity as carbonate precipitates out if it is left standing or aerated hard for more than a day. Mix, aerate until clear, and use the water within about 24 hours rather than storing it for a week.

Does the water need aerating before use?

Yes. Circulate and aerate until the water is completely clear, normally about 20 minutes with this formula, because part-dissolved saltwater puts undissolved carbonate straight into the display tank.