Set up your Culturi-S

AK Culturi-S

Set up your Culturi-S

Eleven steps: four to get the reactor ready, then seven you repeat for every batch. Safety, warranty and troubleshooting are all here too, parked at the bottom until you need them.

  • 11 steps
  • 40 min to set up
  • 5 to 7 days per batch
  • 1 L working volume
View the Culturi-SBack to Launchpad
Phase one

Set up once

Four steps, done once when the unit arrives. The only part that needs real care is the glass.

  1. 1

    Unbox the reactor

    Get the unit out of the box and the lid off the vessel without stressing the glass.

     5 min

    The vessel is only held by friction

    The glass vessel is not fixed to the base unit. It sits in place by friction alone, so treat it exactly as you would any other loose piece of glassware.

    1. Open the box from the top.
    2. Remove the protective packaging from inside the box.
    3. Grasp the top of the unit and lift it out.
    4. Unwrap it carefully. The glass vessel can detach from the light base as the wrapping comes off.
    5. Separate the vessel from the base. Hold it with both hands, thumbs together under the lid and index fingers on the back of the lid, then pull back with your fingers while pushing up with your thumbs. The lid will release.
    6. Take the contents out of the vessel.
    7. Plug the light unit into a power socket, but leave it switched off.
  2. 2

    Fit the rigid tubing

    Slide the glass tube through the seal slowly, and stop a finger's width off the bottom.

     5 min

    You needMicrofibre clothfood-safe lubricant if needed

    1. Push the tubing through the seal slowly, with about the weight of one or two fingers behind it. Lubricant is usually not needed.
    2. Stop when the end of the tube sits roughly one finger width above the bottom of the vessel.
    3. If it needs more slip, use a food-safe lubricant: USP or food-grade glycerin, or a little sterile water-based lubricant. Cooking oil is a last resort.
    4. Wipe the tubing clean inside and out to remove any lubricant residue before use.

    Tubing out before the lid comes off

    Always remove the rigid tubing before you take the lid off the vessel. This matters most with the Pod Core fitted: levering the lid with the tubing still in place risks breaking the tube or the vessel, and cutting yourself on the way.

    Why this matters

    Forcing the tube in too fast or too deep can fracture the base of the vessel, and once the vessel is full of water a fracture there can take the light unit and your bench with it.

    Every glass part on this unit deserves the same care: the vessel, the lid and the rigid tubing are all breakable, and breakage after delivery is not covered by the warranty.

  3. 3

    Sterilise everything

    Vinegar or diluted isopropyl. This is the step that decides whether the culture lives.

     20 min

    You needWhite vinegar or 70% isopropylmicrofibre cloth

    Do not skip this step

    Clean cultures are not possible without clean sterilisation. Sterilise at every opportunity and you remove most of the reasons cultures crash.

    No boiling water

    Do not add boiling water to the vessel or change its temperature quickly. Thermal shock fractures glass.

    White vinegar

    1. Mix 1:1 white vinegar and water in the 1 L vessel, for example 500 mL of each.
    2. Attach the lid.
    3. Swirl vigorously every few minutes, reversing direction as you go, so every surface is covered including the inside of the lid and the rigid tubing.
    4. After 15 minutes, rinse with clean water until you can no longer smell vinegar, then dry everything with the microfibre cloth provided.

    Diluted isopropyl alcohol

    1. If you have 100% isopropyl, dilute it to 70% with water so it does not evaporate before it works.
    2. Spray the vessel and the inside of the lid thoroughly, soaking every surface including the rigid tubing and seals.
    3. Attach the lid and wait 3 to 5 minutes.
    4. Remove the lid using the two-thumb release from step 1.
    5. Dry everything with the microfibre cloth. Once you can no longer smell alcohol, it is ready.
    Why this matters

    There are tougher methods than these two, ranging up to chemicals that are genuinely dangerous to skin and eyes. We have stuck to the simple and safe options here. If you are confident, they are worth researching.

    Whatever you use, avoid:

    • chemical contact with the rubber seals
    • anything that leaves a smell, slickness, film or residue behind
    • scented products of any kind, including items washed with laundry detergent, stain remover or soap
  4. 4

    Prepare your saltwater

    Synthetic salt at 1.022 to 1.026 sg. Natural seawater has to be sterilised first.

     10 min

    You needSynthetic salt mixfresh waterrefractometer

    1. Mix synthetic salt with fresh water. Synthetic is what we recommend, because you do not have to sterilise it.
    2. Match the salinity of the starter culture you have. Ask your supplier for the exact specific gravity, or use 1.022 to 1.026 sg (30 to 35 ppt), which suits most strains.
    3. If natural seawater is your only option, neutralise the life in it with chlorine first, then neutralise the chlorine with thiosulphate.
    Why this matters

    You have dechlorinated correctly if you can smell chlorine before adding thiosulphate and not after.

    Sterilising natural seawater matters because whatever is living in it will happily eat what you are trying to grow.

    Some strains prefer the lower end of that salinity range and others the higher end. Per-strain values are in the lighting and salinity card at the bottom of this page.

Phase two

Every batch

Seven steps you repeat for each culture. Roughly ten minutes of work, then five to seven days of growing.

  1. 5

    Fill the vessel

    900 mL of prepared saltwater, leaving room for the starter culture.

     2 min
    1. Fill the glass vessel with 900 mL of clean, prepared saltwater.
    2. Leave the remaining volume for your starter culture.
  2. 6

    Add fertiliser

    Guillard's F/2 for most strains, then mix it through before anything else goes in.

     2 min

    You needGuillard's F/2

    1. Use Guillard's F/2 for most strains, including nannochloropsis and tetraselmis. Follow its own dosing instructions for the volume in the vessel.
    2. Stir or swirl gently so the fertiliser is evenly distributed. Do not stir with anything that has not been sterilised.
    Why this matters

    Distributing the fertiliser is not strictly essential, but we recommend it. A concentrated pocket of fertiliser sitting against sensitive cell walls can do damage that an evenly mixed vessel never will.

  3. 7

    Add your starter culture

    100 mL of starter into the 900 mL of water, then switch the light on.

     2 min
    1. Turn on the integrated light if it is not already on.
    2. Add 100 mL of starter culture to the 900 mL of saltwater, a 9:1 ratio.
    Why this matters

    The honest minimum is one cell. That really is all it takes.

    We recommend far more than that because a 9:1 water to starter ratio is the safe margin. For the Culturi-S that means 900 mL of saltwater to 100 mL of starter, which is a generous start. You would very likely still succeed with 25 mL.

  4. 8

    Open the airflow

    Air pump on, gate valve wide open. Phytoplankton likes it vigorous.

     1 min
    1. Turn on the air pump.
    2. Open the gate valve on the rigid tubing fully, or as far as it will go.
    Why this matters

    Strong aeration keeps the culture mixed, improves gas exchange and stops cells settling on the bottom. For the common phytoplankton strains this level of airflow is what supports consistent growth.

  5. 9

    Watch it darken

    Slow for a day or two, then obvious. Keep it between 18 and 25 C.

     Days 1 to 5
    1. Expect slow darkening for the first day or two, then a noticeable change day after day.
    2. Hold the water between 18 and 25 C (64 to 77 F).
    3. Above 26 C the culture is stressed. If it is climbing, lower the light brightness to cut the heat.
    Why this matters

    Growing too fast? Shorten the time it spends under light. Too slow? Lengthen it.

    You can also experiment with more fertiliser to reach a higher density.

    Depending on your light schedule and brightness you may hit harvest point earlier than the timeline suggests. If you do, harvest as soon as you can.

  6. 10

    Harvest

    Day five to seven, into a clean 2 L bottle and straight into the fridge.

     5 min

    You needClean 2 L bottle

    1. Harvest around day 5 to 7, when density and health peak.
    2. Pour the contents of the vessel into a clean 2 L bottle.
    3. Refrigerate it unless you are using it immediately.
    Why this matters

    Refrigeration prolongs life significantly, and keeping air exposure to a minimum helps too.

    Avoid collecting the dead and dying cells that settle at the bottom. The healthy phytoplankton is in the water column.

  7. 11

    Reset for the next batch

    Sterilise everything again before you refill. Skipping this is how cultures die.

     20 min
    1. After every harvest, sterilise everything again exactly as you did in step 3.
    2. Once it is clean and dry, start again from step 5, filling the vessel.

    This is the step people skip

    It seems unnecessary, and it is the single most reliable way to ruin the batches that follow. In our experience, neglecting the reset starts the clock on a culture's downfall.

    Why this matters

    The point of the reset is to clear out airborne bacteria that found their way in during the last cycle, before they get a chance to establish themselves on the next one.

Reference

Here when you need it

None of this is required reading to get a culture going. It is here for the day something looks wrong, or the day you need the warranty.

SettingsLighting and salinity by strain

The brightness and salinity we recommend per phytoplankton strain.

  • Nannochloropsis: 1.023 sg, white at 100% brightness
  • Tetraselmis: 1.026 sg, white at 80% brightness
  • T-Isochrysis: 1.026 sg, white at 45% brightness
TroubleshootingIt is not growing, or it crashed

If you are having trouble getting a stable batch going, it helps to step back and remember that phytoplankton is a very simple organism with very simple requirements. Before looking for complicated explanations, start with the fundamentals. These are the most common causes of failure in our own experience.

Contamination

The air around us carries bacteria and other microorganisms, and some of them compete with phytoplankton for the same nutrients. If equipment is not properly sterilised, or the culture sees too much unfiltered air, contamination builds with each harvest until the culture is impure, crashes, or is no longer really a phytoplankton culture at all.

Green cyanobacteria can be mistaken for phytoplankton without a microscope, and excessive cloudiness is often a bacterial bloom rather than density.

Air drying is not recommended. Once equipment is clean, keep it clean and handle it in a way that does not reintroduce contamination.

Unless you are working in an extremely controlled environment, some bacterial presence is inevitable. The goal is not sterility, it is keeping contamination low enough that the phytoplankton keeps outcompeting it. It is also worth keeping a small portion of an earlier, cleaner harvest as a backup in case the main culture starts to decline.

Water source

Anything other than properly prepared synthetic saltwater carries additional risk. Natural seawater and aquarium water introduce bacteria, organics and competing organisms. Do not use them unless they have been chemically sterilised first. There is no practical substitute for that step.

Temperature

Most commonly cultured strains slow down, stress or start to decline once temperatures pass 26 C (78.8 F), and prolonged exposure at or above that can be lethal. 18 to 25 C (64.4 to 77 F) is the range for stable growth.

Other possible causes

  • incorrect salinity
  • poor quality starter culture
  • incorrect or degraded fertiliser, or the wrong dosage
AboutWhat the Culturi-S is

The AK Culturi-S is the smaller reactor in the Culturi range, sized for 1 L phytoplankton cultures. The sealed glass vessel, integrated light and gate-valve airflow all match the larger Culturi-M, just at a smaller working volume.

It works well as a first reactor for a single strain, or as a stable backup feeder running alongside an existing culture. For box contents and specifications, see the product page.

SafetyWorking with the glass

This unit contains multiple glass components. Handle all of them with extreme care, including the rigid glass tubing and the vessel itself, to avoid injury or damage.

When inserting the rigid tubing into the seal, lubricant is usually not required. In most cases the tubing slides into place under very light pressure, about the weight of one or two fingers. Insert it slowly and stop when the end sits approximately one finger width above the bottom of the vessel. Forcing it too far or too quickly may fracture the base of the vessel and may also damage the light unit.

If additional slip is needed, use a food-safe lubricant such as USP or food-grade glycerin, or a small amount of sterile water-based lubricant. Cooking oil should only be used as a last resort.

Because the vessel is filled with water in use, any fracture could also result in water damage to the light unit and the surrounding area if proper care is not taken.

After installation, thoroughly wipe the tubing clean on both the inside and outside of the vessel to remove any lubricant residue before use.

WarrantyAK Culturi-S limited warranty

Aquaculture Kings warrants the AK Culturi-S to the original retail purchaser in Australia against defects in materials and workmanship under normal use for 12 months from the date of delivery.

What this limited warranty covers

At our option, Aquaculture Kings will repair or replace any AK Culturi-S component found to be defective due to a defect in materials or workmanship during the warranty period.

This limited warranty also covers glass vessel damage present on delivery, provided:

  • the damage is reported within 7 days of delivery
  • the claim includes video evidence
  • proof of purchase is provided

What it does not cover

  • damage caused by mishandling, dropping, impact, misuse, abuse or improper storage
  • glass breakage occurring after delivery
  • damage caused by improper assembly or installation, or failure to follow product instructions
  • damage caused by inserting glass rigid tubing into seals without appropriate lubrication, care and caution
  • damage caused by modification, unauthorised repair, chemical exposure or temperature shock
  • normal wear and tear, including seal or O-ring compression, discolouration, or cosmetic blemishes that do not affect function
  • incidental or consequential damage, including loss of use, downtime, lost profits or other indirect losses, to the fullest extent permitted by law

How to make a claim

Contact sales@aquaculturekings.com with proof of purchase, a description of the issue, and a clear video of the product and the affected part. We may require additional information, troubleshooting, or return of the product or component for inspection before approving a claim.

Remedy

If a valid claim is approved, Aquaculture Kings will, at its sole option, repair or replace the defective product or component. Replacement parts or products may be new or functionally equivalent. Unless prohibited by law, the remedies stated here are the purchaser's exclusive remedies.

Shipping

If a claim is approved, Aquaculture Kings may, at its discretion, cover reasonable standard shipping costs associated with the claim. The customer remains responsible for any expedited shipping, duties, taxes or other non-standard charges unless otherwise required by law.

State law rights

This limited warranty gives you specific legal rights, and you may also have other rights which vary from state to state.

Care reminder

Glass components are fragile. To reduce the risk of breakage, lubricate seals before inserting glass tubing, never force or aggressively twist glass components, and handle and store all glass parts with care. Damage caused by failing to follow these handling guidelines is not covered.