HOMEbox Club – Seriotica Grow

Nutrient strategy

VBX & Shine by Hydroponic Research

For plant nutrition, we rely on the innovative nutrient system from California-based manufacturer Hydroponic Research. It consists of two core components: VBX, a complete base fertilizer for both the growth and flowering phases, and Shine, a highly concentrated bloom booster for the final weeks. Both products are mineral-based, pH-stable, and leave no residues – making them ideal for closed systems and repeated use.

VBX provides all essential macro- and micronutrients in an easily available form, while Shine specifically promotes sugar production, resin development, and bud density. Application is simple, safe, and free from buildup – a clear advantage for anyone seeking consistent results and clean flavor in the final product.

Week One: Germination

In the first week of our Seriotica grow, the focus is on maintaining a rather humid microclimate to give young plants the perfect start. With daytime temperatures around 24°C, high humidity levels of 70–75%, and a deliberately low VPD of about 0.4–0.6 kPa, we create ideal conditions for root development. A low VPD is especially important, as it minimizes vapor pressure and reduces water loss through the leaves – meaning the plants don’t yet need to compensate actively through their roots. This reduces stress, supports stable development, and allows seedlings to focus entirely on forming strong roots.

Ultrafine water mist introduced via the humidification system keeps humidity at the target level while simultaneously cooling the grow space through evaporation. As a result, the HVAC compressor hardly ever runs, keeping energy consumption to a minimum.

After transplanting the seedlings into 14-liter pots, they were gently hand-watered with 0.25 liters of water each – enough to last for the first three days. On day four, the plants were given another 0.25 liters of nutrient solution (EC 0.6) by hand. It wasn’t until day six that irrigation was switched over to the automatic watering system.

Week Two – Root stimulation & increased light intensity

In the second week, Seriotica gradually starts to grow out of the seedling stage. We maintain a comfortable daytime temperature of 24–26 °C, with a moderately reduced humidity level of 65–60%, resulting in a VPD of 0.71 to 0.91 kPa – ideal for encouraging the plants to transpire more. To stimulate early transpiration and prevent calcium/magnesium deficiencies, we deliberately raise the VPD early in the HOMEbox Club environment.

Dimming is increased to 60%, resulting in a noticeably higher PPFD of 500 µmol/m²/s. The plants begin to build visible leaf mass. The consistent 18/6 light schedule supports steady growth without stress. During this phase, we also start light watering (2.67 L/week) and introduce a mild nutrient solution (EC 1.2, pH 6.2) to ensure early nutrient availability.

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Week Three – Vegetative phase

The vegetative phase is in full swing. At a comfortable 26°C and 59% humidity, the plants are thriving and visibly growing day by day. Unfortunately, on day 16, we notice that some plants are showing signs of Tobacco Mosaic Virus. For safety reasons, 32 plants are removed from the box and disposed of. We decide to continue the grow with the remaining 44 plants. Due to the reduced plant count, the vegetative phase will need to be extended beyond the original schedule.

VPD at the beginning of the week is around 1 kPa. In the middle of the week, we slightly raise the temperature and lower the humidity to stimulate transpiration. The plants are also starting to drink more water. We’re still using only VBX without any additional additives, and the plants are responding very well. Light intensity is increased to the maximum level for the vegetative phase – 66%.

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Week Four – Vegetative Growth & Switch

By the third week, Seriotica has developed into a strong and vigorous plant. During the first half of the week, we maintain a warm daytime temperature of 27 °C with a reduced humidity of 56%, resulting in a VPD of 1.2 kPa – just right to prepare the plants for the upcoming flowering phase. Starting on day 25, we shorten the light cycle to 12 hours, initiating the flowering stage. The temperature remains the same for now, while humidity is lowered slightly to 55%.

Dimming at the beginning of the week was set to 66%, and with the switch to 12/12, it is increased to 100%, resulting in a PPFD of 750 µmol/m²/s at canopy level. The plants begin to stretch, and we now allow them to grow closer to the lights. This gradually increases the PPFD perceived by the plants. As they start metabolizing more CO₂, exhaust airflow is raised to 40% to bring more fresh air into the box.

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Week 5 – Early Flowering Phase

Everything is going according to plan in the first week of flowering. The plants appear healthy and vigorous, and the first signs of budding are clearly visible. Over the course of the week, humidity is gradually reduced, causing the VPD to rise – encouraging the plants to transpire more. This is also reflected in the daily watering volume: we are currently watering just over two liters per day. We continue to use a single nutrient component – VPX from Hydroponic Research – and are very satisfied with the results.

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Week Six - Flowering Week Two

The plants are now in their second week of flowering and have adapted very well to the 12/12 light cycle. The stretch is in full swing, and the final structure of the plants is slowly starting to take shape. One particularly noticeable aspect is the growth pattern: about three-quarters of the plants are developing strong lateral branches that are nearly as tall as the main stem – a sign of uniform, bushy growth. In contrast, around a quarter of the plants are dominated by a strong central main stem, indicating a more columnar growth form. Overall, the plants are developing very promisingly.

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Week Seven – Lollipopping

In the third week of flowering, the stretch has now finished, and the plants are fully shifting their energy toward bud development. This marks the ideal time to begin lollipopping. Since we’re growing relatively few plants per square meter in this run, we’ll take a very targeted and cautious approach – only removing what is truly necessary.

Lollipopping offers several clear benefits: by selectively removing lower shoots and shaded fan leaves, airflow in the lower canopy is improved, significantly reducing the risk of mold. It also helps the plants focus their energy on well-lit top buds rather than on small, shaded ones – ultimately leading to better quality and higher yields.

The plants continue to look healthy and vigorous – we’re excited to see how the buds will develop over the coming weeks.

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Week Eight – Bud Development and Resin Production

n the fourth week of flowering, plant development is progressing noticeably. Bud formation is in full swing, and the first signs of intense resin production are clearly visible. The plants are beginning to release their characteristic floral aroma, and the buds are becoming denser and more structured.

During this phase, we rely exclusively on VBX, Shine, and Phlo from Hydroponic Research. This combination provides the plants with all essential nutrients and supports both bud development and resin production at the highest level.

The plants continue to look very vigorous, showing strong flowering and developing a uniform, healthy appearance.

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