Acropora Care Guide for UK Reefers

Acropora: Beautiful, Humbling, Addictive

Acropora is the coral that entire reef tanks are designed around — and also the coral most likely to humble even experienced reefers when it randomly RTNs overnight.

UK-Specific Considerations

Tap water quality. High nitrates, phosphates, and silica make an RODI unit non-negotiable for acropora. Aim for 0 TDS output, and replace membranes and DI resin on schedule.

Temperature swings. British houses can swing significantly between day and night. Acros want 25–26°C with minimal variation. Running two heaters provides backup, and a fan or chiller is essential for summer.

Shipping stress. UK-shipped frags can spend 24+ hours in a box. Allow a solid 4–6 weeks before judging any shipped acro.

Recommended Parameter Targets

Parameter	Target
Salinity	1.025–1.026
Temperature	25.5°C
Alkalinity	8.5 dKH
Calcium	430 ppm
Magnesium	1320 ppm
Nitrate	5–10 ppm
Phosphate	0.05–0.08 ppm

That phosphate number catches people out. Old-school advice was "zero phosphate" but acros actually need a trace amount — zero phosphate often leads to bleaching or tip burn.

Feeding

Acropora are active heterotrophic feeders. A zooplankton-based coral food broadcast-fed 3–4 times a week improves growth and colour. Turn the skimmer off for an hour after feeding so the corals get a chance to grab some.

When Things Go Wrong

STN: Tissue slowly recedes from the base up. Usually a flow or water quality issue. Increase flow and double-check parameters with fresh reagents.

RTN: Tissue peels off in hours. Frag above the recession line immediately and move to clean saltwater if possible.

Bleaching: Stabilise everything and wait. Usually caused by light shock, a temperature spike, or a parameter swing. The coral has lost its zooxanthellae but is not necessarily dead.

Finding Good Stock

The UK has an excellent community of SPS keepers who frag regularly. Browse aquacultured SPS frags from UK hobbyists — shorter shipping times and corals already adapted to UK water.