Phyto concentrates until a point and then stops.

[Stelioshah]

Hey guys, I am cultivating some phyto to feed copepods. In order to grow it, I dose a phosphate and an ammonia solution. The phyto grows significantly for a few days and then always just stops, regardless of me adding more ammonia and phosphates. The grown phyto gets as green as you can see in the pictures below (when light is passing through it, at night it looks way darker). Is this normal? Or is there a way to concentrate it even further? My starting culture is way more concentrated than the one I am cultivating (I can't see through it when shining light on it).

The picture was taken by a security camera that's why the quality is that low..

 

[KrisReef]

Are you using ambient light from outside? Perhaps the light is limiting the growth inside the bottle?
Totally a wild guess based upon your description of the issue. The only way to know is to confirm the actual numbers of algae/ cm3 of both solutions, not just a visual inspection.
I believe that your rotifers will eat the algae in any case.

 

[Stelioshah]

Are you using ambient light from outside? Perhaps the light is limiting the growth inside the bottle?
Totally a wild guess based upon your description of the issue. The only way to know is to confirm the actual numbers of algae/ cm3 of both solutions, not just a visual inspection.
I believe that your rotifers will eat the algae in any case.

Yes I am using direct sunlight to grow it. The thing is even if the color is barely noticable, after dosing a bit of ammonia it turns totally green within a day or two. It then stops as in the pictures above as if something is preventing the further growth. That's why I am asking. Does it usually get more concentrated than that? Or this is it?

 

[G Santana]

I use f2 fertilizer that came with the phyto and I get a pretty dark culture. No special equipment, inexpensive light.
Perhaps try using f2, it's inexpensive and lasts a long time. You might get what your looking for.

Good luck

 

[Dinkins Aquatic Gardens]

My guess is that the problem is your fertilizer. We use F2 fertilizer, which includes the needed nitrates and phosphates, along with trace metals and other trace nutrients.