> For the complete documentation index, see [llms.txt](https://help.waterwatch.io/3.0.1/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.waterwatch.io/3.0.1/tank-monitor-positioning.md).
# Tank Monitor - Positioning
* The tank monitor should be installed at least **300mm** above the highest possible water level. **200mm** is the minimum measurable distance above the highest water level.
* [You will need to drill a 50mm hole in the tank](/3.0.1/hole-saw-options.md).
* The sensor should be as close to level as possible, at no more than a three degree angle. Mounting shims are available if your tank has a curved top.
{% hint style="info" %}
If you have a Devan tank, mount the monitor off center. These tanks have metal in the center.
{% endhint %}
Ensure that there are no obstructions directly under your chosen mounting position such as ball cocks, inflow and outflow pipes.
**Plastic tanks**
The best installation spot is on the center of the tank roof. This is usually the highest point and allows a clear view to the water surface. If you have a Devan tank, mount the monitor off center. These tanks have metal in the center.
**If the center of the tank is not flat, there are alternative options:**
The sensor can be installed on the tanks access lid. This is not the best position as false alarms can be triggered if you happen to remove the tank lid for inspection.
As with concrete tanks, the sensor can be installed high (but off center) using the [mounting shims](https://www.waterwatch.io/product-page/t35-mounting-shim) for leveling.
**Concrete tanks**
Mounting high (but off center) using the mounting shims is the standard method for installation on concrete tanks. Some customers prefer replacing the inspection lid with timber to attach the sensor.
##
---
# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.
## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.
Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:
```
GET https://help.waterwatch.io/3.0.1/tank-monitor-positioning.md?ask=&goal=
```
`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.
Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.