More light isn't always better, you can definitely over do it. For flowering, 30W/ft. or 320W/square meter is a common recommendation for efficient, white LED. I believe around 500w/meter is recommended for Mars and other lights using the blurple Epistar diodes. BTW, the actual power rating of the mars 600 II Epistar is 83W in veg, and 260W for flower. Turn on both switches! You really should have more light for flower.I'm guessing higher value PPSF or watts per square foot means better. My tent is 1.2m x 1.2m and height 1.6m. The equipment I have is all my budget would allow me.
On a budget, I suggest adding something like 80 actual watts of common household LEDs. They are typically 8-10 actual watts for a 60w "equivalent" bulb. As for the color temperature, 2700K-4000K/soft white is best for flowering. If you look on the package, it should give the actual watts and color temperature. Removing in the globe/diffuser will increase light output. Florescent tubes are another option. Bottom line, get more light in there anyway you can.
I'm no expert, so your best bet is to ask for supplemental light suggestions in the LED section. There are some seriously knowledgeable people over there. https://www.rollitup.org/f/led-and-other-lighting.124/
Avoid Platinum and other blurple lights. White light is what you want, COBs, strips or boards. I like strips for the high efficiency and superb distribution.
Some efficient and very effective LED...
http://ledgardener.com/diy-led-strip-build-designs-samsung-bridgelux/
www.diyleduk.co.uk
https://true-northern-lighting.myshopify.com
https://www.omegalight.net
www.Cobkits.com
https://www.rapidled.com/vero29-3-x-3-grow-kit/
www.timbergrowlights.com
www.cutter.com.au
https://www.todogrowled.com