Only Dry Season parameters

[TCMontium]

Hello everyone,

It is well know that the easiest time to collect fish in South America is the dry season (changes from around October to January depending on the area I guess) and all the temperature, pH and conductivity measurements in the habitats are done in this season as far as I can see. What about the rest (majority) of the year? I suppose the temperature would be lower and both the pH and conductivity would be higher, but is there any actual measurements from rainy season and other "normal" times of the year? Does anyone go "fishing and measuring" anytime except dry season?.
I know every tiny stream has different parameters, but even a few measurements from some rivers/streams that are known to inhabit dwarf cichlid species would be nice. Some people posted links for weather information all around the year, but that doesn't really tell much about the water parameters (if you are not an expert on weather-river parameter relations in Amazon Basin).
People usually keep the parameters in their aquariums stable and change it only to breed the fish, but it would most likely be healthier (especially for the females and fish that are in their early life stages) to simulate the seasonal changes more realistically than that.
Anyone that simulates seasonal changes for healthier breeding or biotope aquariums or some other reason?

 

[Mike Wise]

Off hand, I can't recall any rainy season water examinations. I have tested small streams after very heavy overnight rain storms. Interestingly, the water values were quite similar to streams sampled in the same area where it hadn't rained for several weeks previously.

 

[gerald]

Does Brazil and Peru have any federal or state agencies comparable to our US Geological Survey and state water quality agencies that measure and post online river stage, flow, and chemistry data? Also City water supply intakes should (hopefully) collect frequent data at their raw water intake. This may not be posted online, but could probably be obtained by calling the chemists at the water treatment plant. Maybe some of our S.Amer members could gather and post this type of info? We could create a "River Habitat Data" sub-forum for this.

 

[gerald]

I asked Brian Perkins the question above and he responded: "The problem is that, as an example, the inlet for city water for Iquitos is located mid-stream in the Nanay River near "Pampa Chica" and normally that is NOT where you find Apistos. Apisto. atahualpa for instance is found in tiny isolated pools of a minor creek that sees very little fluctuation in water quality or temps. from season to season. I have collected it in the same spot in February/March in the wet season and found the water to be 'nearly distilled', 22C, pH of 5.2, and very tannic. Water depth was approx. 30 cm at the deepest point over white sand and in heavy forest cover. In October (the depths of the dry season) the creek had shrunk to a series of pools that were perhaps 20cm deep, and about the size of bathtubs, still extremely soft ( basically RO- my meter had a hard time getting a good reading) pH of 3.8 and temps of 24c. Very black water over white sand with lots of decaying leaves, etc. Iquitos city water is "white water" from the river and so carries a high turbidity, with much higher TDS and pH. (closer to neutral, but it varies) The point being that the info. most useful to the Apisto guys would be if some devoted person made a systematic sampling of the stream water where they are found from month to month, not what would be reported from a city source."