all light will contribute to the PAR value, however only part of the spectrum will actually be beneficial to the tank. basically anything between 400 and 700 nm is useful, anything else is just light. The actinics, assuming that they are true actinics, should produce light at 420 nm, which is actually the part of the spectrum that has the best penetration. The catch is that without enough wattage or intensity, they still will not have penetration to the bottom of the tank. So there are two things to consider with lighting, what part of the spectrum does the light they produce fall within, and how intense is the light? The only way to know for sure would be to take a PAR reading however most of us don't have the meters or the desire to buy them. That said, you need to make sure that you have a light with enough intensity and that contains enough blue spectrum to penetrate to the bottom of the tank. We aim for 4-6w per gallon but realize that if you had 192w produced by 8 24w lights it will not have near the PAR value at the bottom of the tank that your 175w light will have.