Smart Garden Hydro 2.0 FAQs and hydro tips

Congrats on your new Smart Garden. These FAQs combine both growing tips for hydro in general, and FAQs for the Hydro 2.0 model of Smart Garden. You have a Hydro 2.0 if your garden came with 2 grow pots. It will look like this below. Here are the full set-up directions, and below are the FAQ's and hydro growing tips...


Smart Garden Hydro 2.0 with pink grow light on


How do I change the light to auto mode?

The button is at the end of the light arm, shown below. The first press turns on the white light. The second press turns on the grow light (both the button and light will change from white to a pink glow, shown below). Once you're in grow mode, press the button a third time but this time keep holding it down, for about 5 seconds until the light dims, then goes back to full brightness. Take your finger off the button. You're now in auto grow mode.

To double-check what mode you're in, tilt the light arm up and under the button you'll see a blue light has appeared to show the timer's on. The grow light will stay on for 16 hours, off for 8, then repeat. You can play around with the perfect timing for you, but a good tip is starting at 7am. That would mean the light turns off around 11pm, and on again around 7am. It's normal for the timing not to be exact, we're not talking a swiss-made time piece here, so it may shift a little over time. You can turn it off and reset anytime if needed.


Smart Garden Hydro 2.0 light button


Why aren't all my seeds sprouting?

You can use your Smart Garden to grow herbs, veges and flowers indoors, all year round. Seeds like to sprout when temperatures are at least 18 degrees. Raising the temperature to around 23 to 26 degrees will increase germination success further.

Temperatures of 18 to 26 degrees are not much of an issue in a typical kiwi home a good portion of the year depending on where in NZ you live - but if needed you can put your Smart Garden on a heat mat, or shift it to a warmer spot in the house. Remember you want them warm not hot! 

When using a heat mat, make sure it's made for seeds. You may want material between the mat and your Smart Garden (best to refer to the seed mat supplier on what's recommended for the mat you buy).

TIP: When using a heat mat, you may need to occasionally mist your plants. Keep an on eye dry tips or edges. Heat dries the air faster. Shop misters here 

What can I grow in hydro?

You can grow almost anything in your Smart Garden! If you don't want to transplant it later, pick herbs, veges and flowers that reach about 50cm maximum height, so they fit under the light (otherwise you'll need to move them to a bigger container later).

Do your research and pick plants that grow well from seed. You can also use your Smart Garden to propagate from a cutting, but you'll probably get best results by getting some roots growing in full hydro first (such as in a prop vase), then transplant to your Smart Garden when roots have started. Traditionally though, your Smart Garden was made to be used with seeds, for herbs and veges. 

Is there a way to tell if a seed is viable?

Seeds can stay viable for years, but as they age, they slowly lose water in their cells and the plant embryo can shrink and shrivel. Soak older seeds overnight to find the duds. Those that float after soaking won't germinate. The sinkers are the keepers. That tells you the seeds have absorbed water and are ready to grow. 


How deep should I plant the seeds?

Most seeds prefer to germinate in the dark, but some - like lettuce - need light to germinate. Smaller seeds will naturally fall down below the surface of the hydro substrate. Larger seeds may need to be gently pushed down (to about 5mms). Lettuce seeds are best left on the surface. Research the seed you're sowing and what their preferences are. Check the seed guide here


When should I start using the grow light?

Wait for your seeds to germinate first
. Most seeds prefer to germinate in the dark. After their first rounded leaves make way for the plant's first proper leaves, it's time to put that grow light to work. Until the first pair of proper leaves appear after germination, the extra light is not required.


When should I start feeding?

Hydro substrate doesn't offer your plants any nutrients, so it's up to you to feed them what they need, when they need it. The seed itself contains the nutrients needed for germination and the first two sets of leaves. The first 'leaves' you'll see appear are actually little rounded embryonic leaves known as "cotyledon" and it's the second set of leaves count as the first proper leaves. Once they appear you'll need to start feeding. Don't take off those first cotyledon leaves, they'll fall off on their own as your plant matures.


What food should I use for hydro?

The food you choose should say it's suitable for use in hydro, for edible herbs and veges, has no urea, and ideally is a complete food (even better if it says it's complete and balanced).

A food suitable for hydro will usually say so on the label, or will list hydro in the directions for use or product information on the website.

Urea can cause fertiliser burn in container plants. Excess can build up, cause the pH of the water or substrate to become acidic, and burn the roots. Food for outdoor plants often includes urea, which can more easily leach away from delicate roots, but just because a food says it is for indoor plants, doesn't guarantee it will be urea free. Most foods that are free of urea will be proud of it and will say so on the label or in the product info on the supplier's website.

You ideally want a complete food, so look for terms like 'complete and balanced' or 'complete food' or that has 'all 16 essential nutrients', rather than supplying only NPK (Nitrogen, Phosphorus and Potassium). If the label doesn't list all 16 nutrients, it may not be a complete food, but some labels are too small to list them all, so they will usually be listed the supplier's website instead. 

The one I use for hydro is Dyna-Gro GROW (rated for edible herbs and veges, suitable for hydro, urea free, complete and balanced). Dyna-Gro also includes calcium. Calcium is 'just' a micro-nutrient but without it you can end up with smaller or deformed leaves (and not all plant foods include calcium).


dyna-gro grow plant food


I also use a dash of Groconut as a growth booster. 


Groconut plant food in black 45gm pouch by heartleaf philodendron


How much should I feed?

For every 1 litre of water (that's one complete fill of your Smart Garden Hydro 2.0), I use a
 1/2 ml of Dyna-Gro GROW and a 1/4 teaspoon of Groconut. You can adjust these levels to suit the plant's needs.

Once the plant's more established I just use Dyna-Gro, but you can keep using Groconut if you like (it's not the cheapest so I tend to ration my Groconut). 

Check the dose for hydro on the food you've bought, as that's just the dose I use for the food I feed, and a level I find works well across all the various herbs and veges I've grown so far in hydro. You may find some heavier feeders need a higher dose of Dyna-Gro, and lighter feeders need less. The 1/2 ml per 1 litre is a happy medium that works for me.


How many lumens are the lights, and how much power do the lights use?


Your Smart Garden comes with a 7.5 watt LED grow light. Over the course of a day in timer mode (on 16 hours, off 8) it will use 0.12 kWh/day. The light is about 670 lumens.  


Can I use soil instead of hydro substrate?


In theory, yes, but it's definitely not recommended. Potting soil tends to be very fine, which sucks up and retains water. Most herbs and veges dislike being overwatered or staying too wet, which can quickly lead to rot. Soil also does a poor job of regulating available water. Using a hydro substrate like vermiculite is recommended. Seeds germinate well in vermiculite, roots like it, and vermiculite better regulates water without becoming waterlogged.


Why would some leaves be turning yellow?

Just like all plants, there are a few common reasons herbs or vege leaves may turn yellow. Common reasons are too much light, not enough light, temperature extremes, or a nutrient deficiency.

If you locate your Smart Garden somewhere that gets a lot of light already, you may either not need to use the grow lights, or should go on to manual off timer mode and run the lights for shorter, or find a position where the main light source is from your Smart Garden so you're more in control of your plants getting the ideal amount of light.

If your Garden is in an area that gets very warm or very cold, consider somewhere a more even temperature. Between 18 and 26 degrees is ideal.


What are the holes on the side of the base unit?

If you lift the panel on the side where the light goes in, you'll discover two holes. Those are for feeding and refilling the water (shown below).


Smart Garden Hydro 2.0 refill holes on the base unit

Do I have to replace the substrate?

Eventually, yes. You should use new substrate every time you start fresh, after you've transplanted the current plant, or it's finished it's production cycle. Your Smart Garden comes with 2 pots full of hydro substrate. When you're ready to start growing a new plant, discard the old hydro substrate and refill with new. I use vermiculite in mine, easily available from most plant centres and hardware stores. 

What's the white light for compared to the red light?

Both support growth, however the red light is better suited for germination and early growth. You can stay on the red light for mature herbs and veges also, or go off the auto timer mode (as that mode is only available with the red light), and use the white light on manual instead as needed. 

Why would the low-water alert go off if the water level looks okay?

The unit thinks the water level is low based on the float inside. If you check the water level and it's fine, check the float. Two things are possibly happening. The float should move with the water level, so it could be stuck or jammed.

Unplug the base, take out the light, and look inside the base. You'll see a little round white cylinder inside, on the same side the light goes in. You should be able to reach it easily from one of the grow pot openings. Give the float a nudge and it should float up to the same level as the surface of the water and the low water alert will turn off.

If a nudge doesn't get the float moving, build-up could be jamming the float. Empty and clean out the inside of the base unit, refill, and the float should work again. 

The third reason is your light might not be in place properly. Check it's firmly pushed down into place. If that's all that was wrong, the red light will turn off and low water alert will stop.

Where do I find the set-up directions?

Who sells the Smart Garden Hydro 2.0 in NZ?

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