When to dose ferts?

[Ptyochromis]

I have a heavily planted 29g. Stocking is 2xkribensis, 9xendlers 1xblk phantom tetra, 8 glass shrimp and 3nerites + MTS. I just got over a BGA/diatom issue in my tank that was caused by a lack of flow.

Lighting is a 34" 30W t8 and a 26" 20W T8
The tank:


I was wondering how will I know when I need to dose ferts? I have flourish comprehensive suppliment that I used on a previous tank; a 20L with way too much light, that I ruined. Now Im afraid to dose ferts. I have a sword (maybe?), that ends of it's leaves are turning translucent and loosing color.
Here is the plant:


Is this just old leaves or a deficiency?

Also, the dwarf sag (I think) in the foreground, I have had for about a year now and it hasn't done anything. I always thought they spread rather quickly via runners.

Any advice would be greatly appreciated

[Ptyochromis]

Also, the substrate is flourite covered with gravel.

[BBradbury]

Hello P...

I dose my liquid every week when I do my water changes. I just add the appropriate amount to the new water. I've started using hydroponics liquids. My plants really do well with it. I dose it in my biotope tank, too. I attached a pic.

B

[Ptyochromis]

You just dose via the directions? Also what hydroponic ferts do you use, the only hydroponic ferts I have are technaflora.

[BBradbury]

Originally Posted by Ptyochromis

You just dose via the directions? Also what hydroponic ferts do you use, the only hydroponic ferts I have are technaflora.

Hello again P...

I dose a hydroponics fert called "Microblast". I dose about 30 to 50 ml once a week, depending on the volume of the tank.

B

[Ptyochromis]

I see. How did you determine how often to dose the ferts?

[Ptyochromis]

So I did a 1/30 of a dose of Technaflora BC bloom (10ml), a 1/20 of a dose of thrive alive green (5ml), and 3mls of Flourish comprehensive.

IF my math is correct the fish should be fine.