While dovii are found all over Costa Rica in rivers and lakes that usually have pH around 7.5, calcium rich, lake Arenal where they are coveted by sport fishermen, is an enigma. The pH can sometimes drop below 7, and water is quite cold, only around 70"F, and can drop lower.
In mosr rivers nitrates are < 5 ppm, but in Arenal, probably because of agriculture and commercial ferilizer use, and sewage dumped into it nitrate can be quite high
I kept my dovii in mid 70s temps, at a pH of @ 7.8, and moderate hardness.
They went from 2" juvies to over 12" in about a year.
I visited Lake Arenal a few times in the mid 90s and was surprised to find it as cold as it was.
And fishermen said they had more luck with large insects as bait rather than fish like tetras.
Below a breakdown of Lake Arenal data
Lake Arenal, Costa Rica, has a depth that varies seasonally between 30 and 60 meters (100-200 feet), and its water temperature varies less than 4 degrees Fahrenheit year-round.
Here's a more detailed breakdown of Lake Arenal's water parameters:
- Size and Depth: Lake Arenal is the largest lake in Costa Rica, covering 85 square kilometers (33 sq mi) and with a depth that varies seasonally between 30 and 60 meters (100-200 feet).
- Water Temperature: Water temperature varies less than 4 degrees Fahrenheit year-round.
- Water Quality: While Costa Rica emphasizes environmental conservation, surface water quality can be affected by factors like untreated sewage and agricultural runoff.
- Water Use: The lake is a source of water for both hydroelectric power generation and irrigation projects.
- Turbidity: Turbidity was elevated (17.30–78.90 NTU)
- pH: The pH was within 6.86–7.49
- Nitrates and Phosphates: Elevated nitrates (8.0–50.0 mg/L) and phosphates (1.0–9.0 mg/L) were detected at all five sites
