Quick EI question

[Marcel G]

But nitrates aren't toxic for fishes even in a very high level (300 ppm +)

Different animals have different tolerance to different compounds (incl. nutrients), so there is no universal value of toxicity which would be valid for all aquarium critters. Beside this, mature fish has much higher tolerance than the developmental stages (fish eggs, embryos or fry). So while some mature fish may show no visible symptoms of toxicity in water with 300 ppm NO3, the fish eggs, embryos or fry may experience an increased mortality or growth defects. Also some more sensitive fish or shrimps may not breed as happily and willingly as in the clear (unpolluted) water. High level of nutrients is always bad for most aquatic critters.

 

[parotet]

I have found that local river shrimps do not survive in my fertilized tanks, while I've seen them thrive in non fertilized low techs. I think it happens the same with some fancy shrimps which seem to be more nutrient sensitive, isn't it?

Jordi

 

[xim]

In fact, I think the Fe-DTPA can be more stable than Fe-EDDHMA (at least according to my little experiment).

But EDDHA is not EDDHMA. They are not the same thing.
If they were the same, there should not be a study like this:
http://pubs.acs.org/doi/abs/10.1021/jf010313t?journalCode=jafcau

 

[Victor]

I have found that local river shrimps do not survive in my fertilized tanks, while I've seen them thrive in non fertilized low techs. I think it happens the same with some fancy shrimps which seem to be more nutrient sensitive, isn't it?

Jordi

It's related to micronutrients. These are very toxic depending the quantity. I didn't remember properly but something about 0,3 ppm of copper could kill every kind of shrimp easily.