CaribSea Purple-Up
Pack size
237 mL (8 oz)
Cost per litre
Under 1c
Water type
Marine
Pack size
473 mL (16 oz)
Cost per litre
Under 1c
Water type
Marine
CaribSea Purple-Up
Feeds the coralline algae you already have, twice over. CaribSea Purple-Up is a marine supplement for accelerating coralline algae growth on live rock, glass and overflows. It works two ways at once: ionic calcium raises dissolved calcium in the water column, and a suspension of 10 micron aragonite powder settles onto rock surfaces and delivers calcium, strontium, magnesium and carbonate directly where the coralline is growing. Iodine is included to replace what a closed system strips out. It is supplied in a 237 mL (8 oz) or 473 mL (16 oz) bottle and is a marine and reef product only.
What it does, and what it does not do
It does: lift dissolved calcium, deliver carbonate and trace elements straight onto rock surfaces, replace iodine consumed in a closed system, and encourage existing coralline to spread and colour up.
It does not: contain coralline algae. CaribSea is explicit on this point - some living coralline must already be present on your rock or glass for Purple-Up to accelerate anything. It also will not overcome a phosphate problem, because elevated phosphate inhibits coralline growth regardless of how much calcium is available. And it is not a replacement for a full two-part or calcium reactor regime on a heavily stocked SPS system.
Active constituents
| Ionic calcium | Raises dissolved calcium in the water column |
|---|---|
| Aragonite powder, 10 micron | Settles on rock and glass, supplying calcium, strontium, magnesium and carbonate at the surface where coralline grows |
| Iodine | Replaces iodine depleted by skimming, carbon and biological uptake in closed systems |
| Patent | US Patent No. 7,565,883 |
CaribSea publishes the active constituents above but does not publish a full quantitative ingredient declaration for Purple-Up, so none is reproduced here.
Dosage and directions
CaribSea's dose rate is 1 capful (5 mL) per 50 US gallons, no more than once daily. Fifty US gallons is 189 litres, so in metric that is roughly 2.6 mL per 100 litres of system volume per day.
| System volume | Daily dose | 237 mL bottle lasts | 473 mL bottle lasts |
|---|---|---|---|
| 100 L | 2.6 mL | About 90 days | About 180 days |
| 200 L | 5.3 mL | About 45 days | About 90 days |
| 300 L | 7.9 mL | About 30 days | About 60 days |
| 500 L | 13.2 mL | About 18 days | About 36 days |
How to dose it
- Shake the bottle. The aragonite fraction is a suspension and settles out between uses.
- Add the dose to a high-flow area - the sump return chamber or in front of a powerhead - so the powder distributes rather than dropping in one spot.
- Expect temporary cloudiness. That is the aragonite in suspension and it clears as the powder settles onto surfaces.
- Wait at least one hour after dosing before testing calcium. Testing sooner reads the undissolved powder as dissolved calcium and gives a falsely high result.
Keep calcium in range
Maintain calcium between 380 and 420 ppm. CaribSea warns against exceeding 420 ppm on a regular basis, because at that point significant precipitation occurs - calcium and carbonate drop out of solution together, which wastes both and can cloud the tank or coat heaters and pumps. Test before you increase a dose, not after.
Specifications
| Type | Marine calcium and trace element supplement for coralline algae |
|---|---|
| Dose rate | 5 mL per 189 L (50 US gal), maximum once daily |
| Doses per bottle | 47 (237 mL) or 94 (473 mL) |
| Target calcium | 380 to 420 ppm |
| Water type | Marine and reef only |
| Contains live coralline | No |
By bottle size
| Size | Volume | Doses | Supplier code |
|---|---|---|---|
| 8 oz | 237 mL | 47 | CS8530 |
| 16 oz | 473 mL | 94 | CS5304 |
Suitable for, and not suitable for
Suitable for: marine fish-only, FOWLR and reef aquariums that already carry some coralline algae; newly cycled tanks seeded with a piece of coralline-covered rock; systems where you want purple on the back glass and overflow rather than green film algae.
Not suitable for: freshwater or planted aquariums of any kind; tanks with no coralline present at all, because there is nothing to accelerate; and systems already running a calcium reactor or a balanced two-part regime at target calcium, where adding more calcium risks pushing past 420 ppm.
Safety and handling
Keep out of reach of children. Do not dose to a tank without testing calcium first. If the system is already at or above 420 ppm calcium, correct that before starting Purple-Up rather than dosing on top of it.
Store the bottle closed, upright and out of direct sun. Shake before every use.
Care and maintenance
Coralline is slow. CaribSea's own guidance is that noticeably faster growth takes several months rather than weeks, so judge the product on a season, not a fortnight. Keep phosphate low, keep calcium and alkalinity stable, and give the tank moderate light - coralline is often outcompeted rather than starved.
Goes well with
- CaribSea Arag-Alive Fiji Pink - live aragonite sand for the same tank, from the same aragonite chemistry.
- CaribSea South Seas Base Rock - bare rock is what Purple-Up is designed to colour in.
- CaribSea Life Rock Shapes - aquascaping rock that takes coralline well once the tank is stable.
Warranty and delivery
CaribSea does not publish a warranty term for its supplements, which is normal for a consumable liquid. Your rights under the Australian Consumer Law apply regardless and are not limited by that.
Both bottle sizes ship as standard freight. Check the use-by or batch date on arrival and store the bottle closed.
Common questions
How much CaribSea Purple-Up do I dose?
One capful, 5 mL, per 189 litres of system volume, no more than once a day. For a 300 litre tank that is about 7.9 mL daily, and a 473 mL bottle will last roughly two months at that rate.
Will Purple-Up put coralline algae in my tank?
No. Purple-Up contains no coralline algae. CaribSea states that living coralline must already be present on the rock or glass for the product to accelerate it. A single coralline-covered rock from an established system is the usual way to introduce it.
Why did my calcium test read very high after dosing?
Because you tested too soon. The aragonite powder is still in suspension for a while after dosing and a calcium test will read it as dissolved calcium. CaribSea says to wait at least one hour before testing.
Is the cloudiness after dosing a problem?
No. That is the 10 micron aragonite suspension doing its job, and it clears as the powder settles onto rock and glass. Dosing into a high-flow area shortens how long it hangs about.
Can I use Purple-Up in a freshwater tank?
No. It is a marine supplement. Coralline algae is a marine organism, and the calcium and carbonate load would push a freshwater tank's pH and hardness in the wrong direction.
How long before I see results?
Months rather than weeks. CaribSea's own guidance is that rapid coralline growth typically takes several months to establish. If phosphate is elevated, coralline will stay slow no matter how much Purple-Up is dosed.
