Hydrospace Microbial Products


PNS ProBio

PNS ProBio™

Formulated as a multi-purpose live aquarium microbial supplement, coral food, and fish probiotic, PNS ProBio™ contains the purple non-sulfur bacterium (PNSB) species Rhodopseudomonas palustris which will provide nutritional and probiotic benefits to filter-feeding animals, improve water quality, and reduce the incidence of disease in an aquarium. These naturally occurring symbiotic bacteria are especially beneficial to SPS corals and the hosted zooxanthellae algae. 

Like most other heterotrophic bacteria, R. palustris may be used to sequester excess nitrate and phosphate. Additionally, due to certain specialized enzymes, the bacteria will mop up substantial amounts of poorly degradable substances such as detritus (flocculated cellulose) and water-yellowing compounds (polyphenols). The bacteria themselves are then easily consumed by corals, providing a much more natural and easily acquired source of nutrition.

PNS ProBio™ is the food that cleans up after itself!

Nutritional Analysis

R. palustris is rich in carotenoids, vitamins, and polysaccharides which contribute to its function as a feed supplement. Proximate analysis indicates a crude protein content of up to 74%. Essential amino acid (EAA) content comprises ~53% of its true protein content; it is especially rich in stearic acid and oleic acid. Crude lipid has been determined to be around 0.64%. Crude fiber is typically around 2.09%.


Use up to 1.25 ml per gallon per day for best results. There is minimal risk of overdose. Shake well before feeding. It is best to feed just after the lights have turned off in your aquarium, as this is when corals are most active in terms of collecting suspended food particles. Additionally, it may be mixed into various fish foods for use as a fish probiotic during regular feeding. For best results, turn off protein skimmers and UV sterilizers for 30 minutes during and after feeding.


PNS YelloSno

PNS YelloSno™

PNS YelloSno™ is formulated to simulate a marine snowfall. Fermented with Rhodopseudomonas palustris and natural sources of chitin, this premium coral food is rich in B vitamins and trace elements and presents a broad range of food particle sizes (much larger than that of PNS ProBio). The larger particles are especially easy prey for LPS corals, gorgonians, and various other filter-feeding invertebrates.

It is flash pasteurized and refrigerated at just the right stage of development to preserve the particles in their stickiest, most nutritious, partially digested state. As such, it is our only non-live product–despite being made naturally with live bacteria.

PNS YelloSno™  is a valuable part of any reef aquarium feeding regimen.

Nutritional Analysis

In addition to providing the well-known nutritional benefits of R. palustris, this product contains the entire B vitamin complex, including cobalamin which is essential to the health of both corals and hosted zooxanthellae.


Add up to 1.0 ml per gallon per day. Shake well before feeding - shake heavily to produce the finest particles or more lightly to retain some larger particles. It is best to feed just after the lights have turned off in your aquarium, as this is when corals are most active in terms of collecting suspended food particles. For best results, turn off protein skimmers and remove mechanical filtration for 30 minutes after feeding which will allow the food to remain suspended for collection by corals. 


PNS Substrate Sauce

PNS Substrate Sauce™

Designed to help establish a robust microbiome in new aquaria, PNS Substrate Sauce™ contains the same live Rhodopseudomonas palustris PNSB found in PNS ProBio™ as well as Rhodospirillum rubrum. These heterotrophs complement common nitrifying bacteria and fill a different biological niche in the aquarium which results in a quicker, more stable, and complete cycle. Additionally, R. palustris is capable of performing denitrification! 

Rhodopseudomonas and Rhodospirillum are naturally abundant in mature wild reef habitats and play a key ecological role in the microbial community. These bacteria are cultured using seawater and formulated specifically for marine aquaria; this eliminates the lag time typically experienced when applying freshwater-grown microbial products to saltwater systems.

This product contains supplemental phosphate to promote prolific microbial growth during the cycling phase.


The product is intended for a single inoculation in new aquariums and can be safely used alongside other nitrifying bacteria additives. Add 1.25 ml per gallon and repeat as desired during the cycling phase only after phosphate concentration falls below 0.05 ppm.


What are Purple Non-Sulfur Bacteria?

The reef aquarium industry has become increasingly interested in microbiology in recent years, specifically how this microscopic community of organisms affects the health of our aquariums. This enthusiasm coincides with major discoveries in marine ecology, particularly regarding the influence of microorganisms on coral health. Coral biologists now frequently refer to the coral structure as a ‘holobiont’ comprised of the coral polyp host along with a community of symbionts including various dinoflagellate algae and bacteria species. Among these microbes found inside corals are purple phototrophic bacteria - the cornerstone of Hydrospace products. 

R. Palustrus
Live Hydrospace Bacteria

Widely regarded as the most metabolically versatile organisms on Earth, purple non-sulfur bacteria (PNSB) have been broadly applied in commercial agriculture and aquaculture (such as fish probiotics) since the 1970s. PNS bacteria are unusual in that they are heterotrophs that can perform photosynthesis (photoheterotrophy). They prefer organic sources of carbon such as acetic acid, alcohol, and sugar which means they can be proliferated using traditional carbon dosing methods. Additionally, PNSB prefer to consume organic waste and detritus moreover relying on ammonia and nitrite for sources of nitrogen - the bacteria itself is then a very natural and nutrient-rich food source for corals.

Recognizing the immense potential of PNSB as a general aquarium probiotic, Hydrospace initially researched and developed these microbes for in-house use at a major U.S. aquaculture facility. Encouraged by early successes in that work, Hydrospace LLC was born and the flagship PNS ProBio™ was released, soon followed by PNS YelloSno™ and PNS Substrate Sauce™.

Feeding Tips & Frequently Asked Questions

Which Hydrospace Product Should I Use?

PNS ProBio and YelloSno are primarily used as coral food and should be treated as such. Substrate Sauce is designed for one-time use in new aquariums to help establish a stable cycle (including denitrification) and diverse microbiome. 

  • PNS ProBio: All reef aquariums that contain filter-feeding invertebrates. The small particle size is especially beneficial for small polyp corals. Can be used safely in conjunction with PNS YellowSno and cannot be overdosed.
  • PNS YelloSno: All reef aquariums that contain filter-feeding invertebrates. The broad spectrum particle sizes benefit large polyp stony corals. Can be used safely in conjunction with PNS ProBio.
  • PNS Substrate Sauce: Brand new marine aquariums. Only requires a single dose but follow-up doses can be beneficial based on available phosphate. 

How often do I need to dose Hydrospace Products?

  • PNS ProBio: Contains live beneficial bacteria and cannot be overdosed. Treat it like any live coral food (such as phytoplankton) with regular feeding at least once per week (daily is ideal) and adjust based on available nutrients and stocking levels.  
  • PNS YelloSno: Start with a single weekly feeding and adjust dosage based on aquarium stocking and filtration handling. Can be safely increased to once daily feeding as a maximum dose.
  • PNS Substrate Sauce: The intent is to dose Substrace Sauce only once when starting a new saltwater aquarium. Additional dosages can be used as phosphate approaches low concentration below 0.05ppm. 

Can I use a dosing pump?

Yes, Hydrospace coral foods can be delivered via traditional dosing pumps

Do I need to refrigerate it?

Hydrospace’s PNS YelloSno must be stored in a refrigerator. The live products, PNS ProBio and PNS Substrate Sauce do not require refrigeration and may be stored at room temperature. 

Where Can I learn more about Hydrospace and Purple Non-Sulfur Bacteria?

Great question!  Check out Hydrospace.store to find more information about the science behind Hydrospace Microbial Products and how PNS bacteria can benefit your aquarium.