Hydro-Logic ChloraShield SmallBoy/ StealthRO Replaceable Upgraded Filter (20/CS)

The Hydro-Logic ChloraShield Replaceable Upgraded Filter is a carbon block replacement cartridge designed for the SmallBoy and StealthRO reverse osmosis systems. It removes 100% of chloramine from city water supplies, flows at 1 GPM, and filters down to 1 micron. Made in the USA, this cartridge offers a low pressure drop and high dirt-holding capacity — making it a practical maintenance item for any grower relying on municipal tap water.

ChloraShield SmallBoy / StealthRO Filter Specifications

Specifications are derived from the canonical product data for SKU HGC741700. Physical dimensions reflect the cartridge body only.

Specification	Value
Brand	Hydro-Logic
Supplier SKU	HGC741700
Compatible Systems	SmallBoy, StealthRO
Flow Rate	1 GPM (gallon per minute)
Micron Rating	1 micron
Chloramine Removal	100%
Height	9.75 in
Width / Length	2.75 in × 2.75 in
Weight	2.0 lb
Country of Manufacture	USA
Case Quantity	20 per case

Why Choose the ChloraShield Upgraded Filter

Chloramine is a disinfectant used by most municipal water utilities as a replacement for chlorine. Unlike chlorine, chloramine does not off-gas from standing water — it must be actively removed with a carbon block rated for it. Standard sediment or basic carbon filters do not remove chloramine reliably. The ChloraShield cartridge is specifically rated for 100% chloramine removal, which matters for growers on city water who cannot afford chloramine contamination in their nutrient reservoir or hydroponic solution.

• 100% chloramine removal — designed explicitly for city water supplies that use chloramine disinfection, where standard carbon filters fall short.
• 1-micron filtration — captures fine sediment, particulates, and organic matter that could clog membranes or affect plant uptake.
• Low pressure drop — the cartridge is engineered to maintain adequate flow through the filter housing without requiring elevated inlet pressure.
• High dirt-holding capacity — extends service intervals between replacements, reducing maintenance frequency in continuous-flow systems.
• Made in the USA — domestic manufacture with consistent quality control across the case quantity of 20 cartridges.

Best Uses for the ChloraShield Replaceable Filter

This cartridge is sold as a case of 20 and is intended as a scheduled replacement part for SmallBoy and StealthRO systems already in operation. It fits growers who want to stock cartridges in advance and maintain a regular filter swap schedule rather than ordering reactively.

• SmallBoy and StealthRO system maintenance — direct drop-in replacement for the pre-filter stage in both Hydro-Logic compact RO platforms.
• Municipal tap water treatment — essential for any operation pulling water from a city supply that uses chloramine rather than chlorine. Chloramine cannot be removed by simple carbon without a properly rated block.
• Hydroponic nutrient reservoirs — removes chloramine and fine particulates before water enters the reservoir, protecting beneficial microbial activity in organic or living-soil adjacent setups.
• Coco coir and rockwool systems — pre-filtering source water to 1 micron reduces the risk of sediment buildup in irrigation lines and drip emitters.
• Commercial and multi-system grows — buying by the case of 20 provides enough cartridges to service multiple units or a full grow cycle without reordering mid-run.
• Paired with a compact RO unit — for growers also using the Hydro-Logic Micro 75 GPD compact RO system, stocking ChloraShield cartridges ensures the pre-filter stage is never the bottleneck.

Compatibility

The ChloraShield cartridge in this listing is sized and rated for the SmallBoy and StealthRO filter systems from Hydro-Logic. These are among the most common compact RO units in the hobby and commercial hydroponic market. The cartridge fits the pre-filter housing on both platforms and is the upgraded carbon block version — replacing the standard carbon filter that ships with those systems.

If you are running a different Hydro-Logic platform, check the housing size and connection type before ordering. Hydro-Logic also produces ChloraShield cartridges sized for the TALLBoy and BIGBoy filter housings — those are separate SKUs with different physical dimensions. This SmallBoy/StealthRO cartridge measures 9.75 in tall by 2.75 in in diameter.

For growers who also need supplemental aeration in their reservoir, an active aqua air pump can complement the filtration setup by maintaining dissolved oxygen levels in treated water.

Usage Guidelines

Carbon block cartridges like the ChloraShield have a finite service life measured by total volume filtered and incoming water quality. Higher levels of chloramine, sediment, or organic matter in source water shorten the effective lifespan of each cartridge. The following general guidelines apply to most SmallBoy and StealthRO installations:

• Monitor inlet and outlet pressure — a significant drop in system output flow rate is often the first sign that the pre-filter cartridge is loaded and needs replacement. The ChloraShield’s low-pressure-drop design means any noticeable reduction in flow is a reliable replacement indicator.
• Replace on a schedule — for consistent protection, replace cartridges based on volume processed rather than waiting for visible performance loss. Manufacturer documentation for the SmallBoy and StealthRO systems includes recommended replacement intervals.
• Do not bypass the pre-filter — the ChloraShield carbon block protects the RO membrane downstream. Operating without a functioning pre-filter accelerates membrane fouling and reduces RO membrane lifespan.
• Flush after installation — after inserting a new cartridge, run water through the system for a short period before using the filtered output in a nutrient reservoir, to clear any carbon fines from the new filter block.

Sources & Further Reading