Cultiuana CT-800 Review

The Cultiuana CT-800 is a foldable LED Bar Grow light with about 800-watts of power. It has an interesting reverse hinge design and is well made. The clear selling point for the CT-800 is the cost. It is considerably less expensive than similar models from other brands. The CEO of Cultiuana claims that it is “the best value for its performance”. I am always on the lookout for great deals for growers. I decided to test the CT-800 to find out if his claim was true.

Cultiuana is the retail sales division of a Grow Light Manufacturer. There are many companies that appear to offer excellent prices, but it can be hard to know about quality and performance. Growers rightly worry whether companies will honor warranties or even offer any customer service. I understand the concerns and I will not review lights until I am confident that I can guarantee customer service. As with all the companies that I review, if you buy a Cultiuana light using our code and later have trouble resolving customer service or warranty issues, I will intervene on your behalf.

There is no doubt that the Cultiuana CT-800 has a great price. We have a 10% discount code (CCFC) for Cultiuana.com. With the discount, your cost for the CT-800 is only $459, and that includes free shipping. Comparable lights that I have tested are at least $550. So, the purchase cost is almost $100 less. However, a better gauge of value is what we call “cost efficiency”: micromoles of usable light divided by the purchase price. In my official ePAR test, the CT-800 delivered 1690.7µmol of usable light, which is a record setting cost efficiency of only $0.27/µmol!

Cost efficiency is one of the critical metrics for evaluating grow light value. However, it only looks at the amount of light and the purchase price. It does not consider the efficiency of the light itself and how well it converts electricity into usable light. That metric is called “Photon Efficacy”. Photon efficacy determines how expensive a fixture will be to run.

There are other metrics that are important. In addition to the amount of light, the amount of electricity, and the amount of money, growers should also consider the distribution of the light. LED bars have come to dominate because they are good at distribution. With enough power and a good distribution, any LED bar fixture can create a good PAR map. In many cases, it comes back to how much money it will cost (cost efficiency) and how much electricity it will use (photon efficacy). Of course, most fixtures that excel in one of these metrics do not excel in the other.

The Cultiuana CT-800 has an interesting LED bar design. There are many foldable LED bar fixtures. They fold to save space and reduce the cost of shipping. Almost all of them fold so that the diodes fold in and are on the inside when the fixture is folded. The CT-800 is the reverse. The diodes point outward when the fixture is folded. There is a distinct advantage to this design: when it is opened it is already in a position to be hung up with the diodes down. However, it is designed to hang only from the central chassis, which can make it a challenge to hang it level.

The drivers are built into the central chassis. There are two 400-watt drivers manufactured by Novbo. With fixtures like this, growers sometimes will complain that the drivers are not removable. However, drivers are only responsible for 7-8% of the heat that comes from an LED grow light. The vast majority of the heat comes from the diodes!

The Cultiuana CT-800 uses Ebright and Sanan diodes. There are 2400 full spectrum diodes at 3800K and 384 red 660nm diodes. The CT-800 also features 96 Far-Red 730nm diodes. There are a total of 2880 diodes, which is about 3.6 diodes per watt or 0.28 watts per diode. Although the diodes are not from the more popular brands, at that current, they should have good efficacy and longevity.

With fixtures this size, I run our official tests in a 5’ x 5’ area with a maximum PPFD in the PAR range at exactly 1000 µmol/m². To set the PPFD, I adjust the hanging height. The Cultiuana CT-800 hit a maximum PPFD of 1000 µmol/m² at a hanging height of 47cm (18.5in). The PPFD in the corners drops just below the 500 µmol/m² threshold. Otherwise, the distribution of light is great.

I run both PAR and ePAR tests. Par is light from 400-700 nanometers. Traditionally, it was considered the only light that powered photosynthesis. In the last several years, research with advanced LEDs and lasers have demonstrated that far-red light from 700-750 nanometers is also photosynthetically active. The new metric ePAR (extended PAR) adds far-red to the traditional PAR range. ePAR is 400-750 nanometers. The ePAR test results are the best representation of the growth potential of a grow light.

All full-spectrum LED grow lights generate some far-red light. Full spectrum diodes use a 450nm semiconductor and phosphor to filter that blue light to longer wavelengths. About 2-3% of the light will end up in the far-red range. The CT-800 also uses far-red diodes, which contribute to the ePAR results but are not measured in the PAR test. The CT-100 delivered 107 µmol of Far-Red light, which is over 6.3% of the total flux. That is suitable for veg and flower.

In the ePAR test, the Cultiuana CT-800 delivered 1690.7 µmol of usable light and pulled 762 watts from the wall. That is a Photon efficacy of 2.22 µmol/w. Just a couple years ago, I would have considered that excellent. It is better than almost any quantum board or COB. It is way better than HPS. However, LED bar fixtures have pushed to higher efficacies. The most popular models are getting about 2.3-2.5 µmol/w in my official ePAR tests (see my reports for the Mars Hydro FC-E8000 and the Spider Farmer SE7000).

The Cultiuana CT-800 generates a perfect amount of light for growers in a 5’ x 5’ tent running exhaust without supplementing carbon dioxide. However, at this price point, I expect a lot of growers will be interested in setting it up in a 4’ x 4’ tent. If you run a sealed space with elevated carbon dioxide your plants may be able to handle a PPFD up to 1500 µmol/m². In that case, you can run the CT-800 at full power in a 4’ x 4’ space. However, most growers will want to set the on-board dimmer to 80%. I ran tests for both applications.

For growers with elevated carbon dioxide, I set the Cultiuana CT-800 at 30.5cm (12in) above the sensors in the 4’ x 4’ test area. The maximum PPFD in this setting is 1327 µmol/m². The CT-800 is nearly the same size as the test area. As a result, the distribution of light across the canopy is excellent. In the ePAR test, almost the entire canopy is above 1100 µmol/m². However, the edges along the ends of the LED bars drop just below 1000 µmol/m². In terms of Usable PPF and Photon Efficacy, the smaller test area and the closer hanging height practically cancel out, so the CT-800 nearly matched its performance in the official 5’ x 5’ test.

Most growers with a 4’ x 4’ tent run an exhaust fan to manage climate. In that case, it is usually not possible to elevate the concentration of carbon dioxide. This is perfectly fine – it is the way that I and most home growers grow. But in that type of grow I recommend limiting the maximum PPFD to 1000 µmol/m². To reach that limit with the CT-800 in a 4’ x 4’ space, I dimmed it to 80% and gradually raised it.

The Cultiuana CT-800 makes impressive density maps at 80% power, 48cm (18in) above the sensors. At 80%, it still pulls 624-watts which is plenty of power. And with a tight fit and good hanging height, the distribution is incredible. Big LED bar arrays, always crush this test. The maps are always incredible. The difference is how much power each fixture needs to generate them.

I have run similar tests with the Cultiuana CT-800, Spider Farmer SE7000, and Mars Hydro FC-E8000. All three ePAR maps are excellent and comparable. To create the maps, the CT-800 pulled 624-watts, the SE7000 pulled 584-watts, and the FC-E8000 pulled only 577-watts. However, the SE-7000 costs about $672 (with Code CCFC on Spider-farmer.com), the FC-E8000 costs $611 (with code CCFC on Mars-hydro.com), and the CT-800 only costs $459 (with code CCFC on Cultiuana.com). So, in this case, the tradeoff is that it uses more power, but costs a lot less to buy. For most growers, I think that is one way to understand the “value”.

I measured the surface temperatures in the 4’ x 4’ area. The fixture had been running at full power for several hours. The room is climate controlled at 25.5C (78F). The LED bars hit a high temperature of 48.3C (118.9F). The central chassis which houses the drivers hit a high temperature of only 40.4C (104.7F). The surface temperatures do not correspond to the heat that a fixture will add to your space. The heat added is a function of the power draw. At full power (762-Watts), the Cultiuana CT-800 will generate about 2,600 BTU/hr.

The Cultiuana CT-800 has an on-board dimming knob. It has preset options for 40%, 60%, 80%, and 100%. You can also daisy chain fixtures and/or use an external (0-10v) controller. I tested the on-board dimmer in the 5’ x 5’ test area. As you can see in the chart, the dimmer ran a bit stronger than expected, but it is close.

The Cultiuana CT-800 has what home growers need from a light. The build quality and components are fine. It has plenty of power and can create a good distribution of light. The price is exceptional! Saving $150-$250 now is certainly an incentive. However, it is somewhat less efficient than other options. In a lot of cases that will just mean that you run more power. If you struggle with heat issues, or pay a lot for electricity, you may want to look for a model with better Photon Efficacy. But, if you are on a tight budget, the CT-800 can get you growing with a ton of light at the best cost per micromole that you can find. What is “The Best Value” just isn’t always the same for all growers!