MasterLine Phosphate bottle on a white background

MasterLine Phosphate

4.8(26)reviews
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In stock
$100.00 away from free WA delivery Free delivery over $100 in WA ($150 elsewhere in Australia).
Free pickup in KenwickOpen Tue to Sat, 12pm to 6pm

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About this product

MasterLine Phosphate — Targeted PO4 & Potassium Fertilizer

Take precise control of your phosphate levels. MasterLine Phosphate is a targeted liquid fertilizer combining Phosphate (PO4) and Potassium (K), designed for aquarists who dose individual nutrients for maximum control over their planted tank chemistry.

Key Features

  • Phosphate (PO4) + Potassium (K) — two essential macronutrients in a single targeted formula
  • Promotes faster plant growth — adequate phosphate availability accelerates healthy plant development
  • Indirectly prevents algae — vigorous plant growth outcompetes algae for nutrients
  • Precision dosing — ideal for EI, PPS-Pro, or any custom nutrient regime
  • 500ml — concentrated for long-lasting use

When your plants need phosphate and you need control, MasterLine Phosphate delivers both without compromise.

Delivery and returns

Free delivery over $100 in WA and $150 elsewhere in Australia. Free pickup from our Kenwick store, Tue to Sat, 12pm to 6pm.

Returns policy

  • 5 stars: 22 (85%)
  • 4 stars: 3 (12%)
  • 3 stars: 1 (4%)
  • 2 stars: 0 (0%)
  • 1 star: 0 (0%)
N
Nathan Roberts
Works well

Solid all rounder fert.

E
Ella Kelly
Noticeable difference

My previously struggling plants have bounced back. Greener and growing fast.

C
Caitlin Sharp
Effective

Clear improvement in plant vigour and colour. Will buy again.

C
Charli Fraser
Part of my routine

Dose this with my other Masterline bottles. Excellent results.

P
Patrick Coleman
Great improvement

Plants perked up quickly. Simple to add to my routine.

B
Blake Parker
Precise dosing

Love being able to target exactly what my tank needs. Plants responding brilliantly.

O
Olivia Wood
Brilliant results

My aquascape has never looked healthier. New growth everywhere since I started using this.

A
Archie Mitchell
Top fert

Does exactly what it promises.

J
Jack Smith
Recommend

Easy dosing, great growth, no algae.

H
Henry Ellis
Solid choice

Reliable results and a generous bottle. My planted tank is thriving.

B
Bella Campbell
Pro level

Taken my tank to the next level. Clean, healthy, vibrant growth.

J
Jasmine Bell
Excellent

Plants greened up within days. Will repurchase.

R
Riley White
Strong growth

Trimming twice as often since using this. Plants are loving it.

R
Ruby Ross
Great for planted tanks

Targeted dosing my plants clearly respond to. No algae problems.

S
Sophie James
Love it

Best fert range I've used so far.

D
Demi Cox
Happy with results

Easy to use and effective. My stems are growing noticeably faster.

M
Madison Howard
Good value fert

Affordable and effective. Whole tank looks healthier since dosing.

M
Mikayla Coleman
Easy to use

Simple dosing and good value. My plants are thriving and pearling more than ever.

D
Dion Shaw
Great fertiliser

Does the job nicely. No algae issues when dosed correctly.

T
Trent Baker
Good product

Steady improvement in plant health. No staining or cloudiness in the water.

T
Tanya Lambert
Value for money

Large bottle that lasts. Effective and easy to dose daily.

T
Trent Walsh
Highly recommend

Great bang for buck. The Masterline range has my plants vibrant and healthy.

B
Brayden Dixon
My go to

Been using this for months. Consistent results and my tank has never looked better.

R
Renee Day
Plants love it

Noticeable difference in growth within a couple of weeks. My stems are greener and fuller. Easy to dose.

P
Pete Hughes
Lush growth

Within a fortnight my plants really took off. Clearly providing what they were missing.

W
William Black
Vibrant plants

The colour and growth improvement has been impressive. Worth every cent.