Fertilization fine-tunning

jpantoja

Junior Poster
Jun 7, 2009
4
0
1
Hello all,

Would somebody please give me some feedback on the following issue?

I am currently daily dosing with Tropica plant nutrition and Seachem N, P and K. However, the doses recommended by the manufacturers seem to be very small for tanks heavily planted.

I wonder whether it is more technical to (1) give the plants the minimum amount of nutrients they need per day or (2) keep excess levels of nutrients (I am assuming it is more than neccessary) as in the estimative index approach?

As I said, am currently using the first method with commercial products but I feel I do not really know if the plants’ requirements are being met, nor if I am excessively using nutrients. Algae growth is well controlled (it could be better I guess) but every time I test my water, the levels of ammonia, phosphate and Iron are below the detection limits of tests commonly available.


My tank’s parameters are:
29-gallon, mature (about 1.5 years), bottom totally covered with HC (“cuba”) and 120 W of light (full light for 7 hours and half light for 3 hours, during early morning and late afternoon) and CO2 (about 1 bubbles per 1.5-2 seconds). Water change is done weekly (about one third of the volume).The pH is 6.8 and GH is 5.0. I am currently using 1 mL of Seachem N, 1 ml of Seachem P, 1.5 mL of Seachem K and 1.5 mL of Tropica plant nutrition for micros daily. There is very little algae growth, but still noticeable on the glass 10-12 days after cleaning. There is no algae growth on plants at all.

How would I know if this amount of nutrients meets the plants’ requirements? I am tempted to start increasing the doses substantially but I would like some reference to be based on. I am afraid of experimenting excessive algae growth. What’s the amount of nutrients (in terms of P, N, K and Fe recommended daily by the estimative index strategy? Is there literature about it? I would not like to prepare fertilizers at home until I learn more about fertilizing.

I appreciate your help,

jpantoja
 

Philosophos

Lifetime Charter Member
Lifetime Member
Mar 12, 2009
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The recommended doses are stupidly low from just about any fert company when it comes to a high light tank. If you want NPK targets, check out the stickied EI thread over in the EI section of the forum. For that matter, read through as many as you can; each one has taught me something valuable.

Your light level is very, very high. I can't believe you're not getting algae at 4wpg and such a low bubble rate. Your fert ratios must at least be balanced decently, or the bulbs old perhaps.

Either way, EI has only solved algae problems for me. When I slack, it creeps in, when I do things properly, it goes away. This is pretty much the consistent story I've heard from others as well.

-Philosophos
 

jpantoja

Junior Poster
Jun 7, 2009
4
0
1
Thanks for getting me started in the forum,

I forgot to mention that I used Excel too, 3 mL a day, so it should be helping the low Co2 bubbles rate. You are right, my bulbs are in fact old (about 6 months). I will try decreasing the light a little and increasing the fertilizers to see the response. I will also go through all the material posted.

Thanks again,

jpantoja