Could ATS growth be limited by low phosphate?

[Levinson]

Hi,
I'm running a diy horizontal ATS on my 29g invert only tank.
The algae's been growing pretty well initially but the growth has slowed down over the past few weeks.
I've checked the water parameters and the nitrates are at around 20~30ppm (api test), the phosphates are at less than 0.03ppm (selifert test).
The levels seem to have stayed about the same over the past month and a half. (One 10% water change)
From I've heard, the ideal nitrate to phosphate ratio is meant to be 16: 1. Could it be the growth is limited by the low phosphate?
Is 0.01~0.03ppm even low? (It does seem pretty low if I think about the 16: 1 ratio thing)
I do have a bottle of phosphate from brightwell aquatics so I could dose some if I really wanted to but I'm too scared to. Should I give it a try?
Or is the simple water change way to go to lower the nitrates? Seems like I have to do a large % change to make a dent on the trates level.

 

[laverda]

I would not worry about your nitrates especially if all you have is inverts. Most corals will be fine at those levels. Although I would not trust your API test kit. Iron is a common limiting factor for algae growth.

 

[Levinson]

I would not worry about your nitrates especially if all you have is inverts. Most corals will be fine at those levels. Although I would not trust your API test kit. Iron is a common limiting factor for algae growth.

Thanks,
I don't have any corals and it's mostly shrimps and pods.
I keep hearing the api test kits suck and I wish I've known before getting it.

 

[laverda]

Most of us here started with the same kits I am sure. If not I doubt they would sell any. It is really a shame they have not improved their test kits over the years.