Neptune ATK V2 Auto Top-Off System
NEPTUNE_ATK_APEX_INTEGRATED
The Neptune Systems ATK (Apex Tank Kit, shown here as the current ATK V2) is a complete automatic top-off system that runs standalone or integrates with an Apex controller for...
Or build it into a bundle — save up to 6% ↓What it is, and who it is for.
The Neptune Systems ATK (Apex Tank Kit, shown here as the current ATK V2) is a complete automatic top-off system that runs standalone or integrates with an Apex controller for added features and monitoring. It uses dual optical sensors with no moving parts, IQ-Fill water run-time intelligence, and a mechanical float valve for three layers of overfill protection. The kit includes a 24V DC PMUP v2 pump rated at 100 gph plus tubing and a magnetic mounting bracket.
Build around the Neptune ATK V2 Auto Top-Off System.
It's already in your system below. Add the flow, filtration and dosing around it and the discount starts working — tiers climb as the build grows, and the reef meter fills with it.
Pick the right one, not the biggest one
The honest line-up from ato & ro/di. Most buyers reading this page should buy the middle column.
BRS 5-Stage 75 GPD RO/DI System
Neptune ATK V2 Auto Top-Off System
Kamoer X2SR Auto Water ChangerAsked before checkout
The questions our support inbox actually gets.
Does it ship quickly?+
Orders placed before 2 PM ET on a business day leave the same day. Tracking is emailed the moment the label prints.
What if it's the wrong fit for my tank?+
Return it. 30 days, no restocking fee, refund to the original payment method. Better: tell us your tank first and we'll spec the system for free — half of all returns are sizing problems.
Who handles the warranty?+
We do. Everything carries the manufacturer's warranty and we run the claim for you — one email to us instead of a ticket queue.
How does the bundle discount work?+
Add items in the bundle builder: 2+ items saves 5%, 3+ saves 8%, 4+ saves 12%, and 5+ saves 15% off the whole system, applied at checkout.