Algae in sump

[Jasonrusso]

I recently bought some chaeto algae to put in my sump to help with higher than desired nitrates. I don't have a fuge, so I just put it in my bubble barrier and got a desk light with a 6500K bulb.
Well, my nitrates are pretty low now (about 5ppm, not sure if it is the chaeto or the bio-pellets). The chaeto hasn't seemed to grow that much. I'm not sure how fast it grows, but it is still really dark green.
Because of the light (I leave it on 24/7), I have all sorts of other dark red algae in the sump now. I bought a couple turbo snails and put them in the sump to eat some of the undesired algae, but they both died. Is this because of the light? Do they need light cycles? They were doing a good job before they died.
Is this algae an issue other than just being unsightly?

[Sniperhank]

The algae that is growing is what is lowering your nitrates. The issue it can cause is by clogging up the bubble trap if it gets too thick.

[Jasonrusso]

Why does the chaeto not grow? Does it grow very slowly? It looks like I have good conditions for algae growth.

[Sniperhank]

It isn't growing because it is able to out compete the cheato.

[buxndux]

I've heard that under continuos light certain algaes will remain in an asexual phase and won't really grow/spread a whole lot. Once they experience a typical diurnal light pattern they enter a sexual phase that leads to greater growth. First off, this idea really doesn't make a whole lot of sense to me.. Second, I was told this by someone else and I haven't done my own research. Good luck