7ft ceilings, what size lights?

Cannasutraorganics said:

As you stated gavita attached the ballast to the fixture to increase output. The longer the run of cord the less efficient. They also say maximum length from ballast so that tells you shorter is better if they won't run if to long. Please test it. Also test making your own cables out of 2 sizes up wires.

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That is not what I stated at all. Would you care to reference that? What I said is that Gavita attaches the ballast directly to the reflector to eliminate RFI.

Bigger wires? I've been doing electronic/electrical work for years in a professional capacity. The cable sizes supplied by the manufacturers are just fine and no advantage will be realized by using larger cables. If bigger cables made for higher output, commercial growers would be all over it.

The laws of physics are still intact. As previously stated, a 1000w Digistar DE bulb dimmed to 600w outperforms a 600w Phantom SE bulb (USHIO). This is exactly as expected since the Digistar is operating at a higher frequency than the Phantom. All of the equipment used for this test is top notch and reasonably new. The bulbs have roughly the same number of hours.

This test is far from perfect. I am using an analog lux meter from Hydrofarm. Those measurements that fell in the lower end of the x100 scale were left out as I feel that the margin of error in that area may be excessive due to potential inaccuracy relating to the visible reading.



Edit: For point of comparison, a 2' T5 produces between 12,500 - 15,000 at the bulb surface.
Note: The 4' measurement point does not account for the height of the meter. The correct point would thereby be 3' 8.5".

bluerock said:

Where are you getting this shielded cable from? I haven't seen any in this industry. Done right, it ain't cheap.

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Good call. I could have swore I saw some before, but checked an old cable laying around and it wasn't shielded.

Cannasutraorganics said:

There is so much wrong with that graph.

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I didn't make that graph, Gavita tech support gave it to me. If you still don't believe its correct, well that’s up to you.

- Jiji

I have 7 foot ceilings too and I use 600w with eye hortilux hps bulbs, cant grow big trees but you can grow bushy beasts that yield a lot if you top and bend them over. I use blockbuster 6 inch hoods and they cover a 4x4 area well.

bluerock said:

That is not what I stated at all. Would you care to reference that? What I said is that Gavita attaches the ballast directly to the reflector to eliminate RFI.

Bigger wires? I've been doing electronic/electrical work for years in a professional capacity. The cable sizes supplied by the manufacturers are just fine and no advantage will be realized by using larger cables. If bigger cables made for higher output, commercial growers would be all over it.

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Your wrong. They attach it to help increase efficiency.
Let me ask a question. What kind of electricity is running to the bulb? It's not ac.

jijiandfarmgang said:

Good call. I could have swore I saw some before, but checked an old cable laying around and it wasn't shielded.



I didn't make that graph, Gavita tech support gave it to me. If you still don't believe its correct, well that’s up to you.

- Jiji

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I've read it before. Discussed it with them and others. Not accurate. its a sales tool....

Cannasutraorganics said:

Your wrong. They attach it to help increase efficiency.
Let me ask a question. What kind of electricity is running to the bulb? It's not ac.

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As to the Gavita graph that you continue to disparage, what exactly is your problem with it? I'd say the data looks to be in-line with expectations of the represented equipment. Furthermore, the equipment being compared is all Gavita. How is that a "sales tool"?

With indoor gardening, it is frequently desirable to get the heat out of the grow room. That is why ballasts are installed remotely. However, this practice results in excessive RFI with high frequency ballasts. There has been considerable concern in the industry about this matter. Hydrofarm addresses it by selling such ballasts as "commercial". Gavita does not sell their PRO line ballasts separate from the reflectors.

In a greenhouse, a remote ballast is not desirable for any reason. The manufacturer saves money on cabling since they are not providing a lamp cord. RFI is not thereby an issue.

Let me ask you a question: Do you see diodes in the schematics for HPS ballasts? I don't see any other than the low frequency offerings from Hortilux and Advanced. What does that tell you about the voltage being used at the lamp in the vast majority of HPS ballasts? It is not DC.

4 solis tek DE 600s

Go with the 4 600s