The manuscript presents a comprehensive database on groundwater levels and physico-chemical properties with high frequency measurements and sampling in the small Weierbach catchment in Luxembourg. This type of data is fundamental for sustainable water resources management, environmental and public health protection and future planning in the face of climate change. In times of dynamic changes in natural environment, we need as much of this type of data as possible from different areas.

The description of the data base, the data acquisition methods and the possibilities for their use have been clearly and accurately drawn up. It is evident that the authors have applied rigorous data quality control criteria. And I have no doubt that this database can be a valuable and useful source of information for scientists.

However, these are not the first studies conducted with such high frequency. There are experimental catchments in Europe where similar measurements have been carried out for a longer time. Examples include the TERENO experimental catchments in Germany https://www.tereno.net/, including the Wüstebach catchment, which is relatively close to Weierbach and with similar environmental conditions. Sampling of groundwater and determination of its chemical properties also takes place there on a weekly basis. It would be good to refer to measurements in other areas; is the research described by the authors part of the current of European research, or does it contribute something more?

Secondly, I have my doubts that data collected for one year can be sufficient to determine ‘catchment response to hydrological change’, ‘ catchment seasonal variability’, ‘dynamics between shallow and deeper flowlines’ and whether it is sufficient for any modelling. Each year is different and at least several years of data are needed to demonstrate any patterns. Perhaps some statements could be reworded or softened.

Thirdly, the authors extensively describe the usage and applications of the data, but what about the weaknesses or limitations of data usage? A paragraph or subsection discussing these limitations and how to address them would be helpful.

Specific comments:

Lines 43-45: This sentence requires references.

Line 94: I suggest adding ‘level’ between groundwater and monitoring.

Lines 121-127: It is not clear to me whether the field measurements were conducted directly in the borehole or if the water was first collected and then measured. If it’s the latter, into what kind of container was the water collected, was the measurement taken immediately after collection or with some delay, and what was the volume of such a sample?

Line 186: Does the provided database from one-year monitoring campaign truly allow us to address the mentioned problems? Isn't there a need for longer measurement series? Perhaps the authors should soften this statement somehow, for example, by discussing the potential of the data, etc.

Lines 187-188: The authors mention previous studies, but they do not specify which studies they are referring to. It would be helpful to include references to these studies here.

Lines 200-202: Same as previous. Provide references to these previous studies.

Lines 220-221: Provide some exaples/references.

Lines 231-233: Same as before. The references are missing.

Lines 248-249: What do you mean by 'extends beyond conventional monitoring efforts'? In other experimental catchments, groundwater measurements have also been conducted on a weekly basis for several years. It would be good to reference these studies and clearly state what is new about your measurements.

Line 260: I would rather write about the potential significance of this database, provided that the measurements continue, because can a one-year measurement campaign really address these issues?

Figure 5. The text refers to Figure 5, which is supposed to show graphs of SO4 and NO3 concentrations, but they are missing from the figure. Additionally, there is no need to repeat the DO and pH graphs on the lower plot, as they are already present on the upper one.

Technical corrections:

Line 24: remove dot after “reactive rock formations”

Figure 4: I would eliminate the black outlines of the circles, as it is difficult to distinguish the colours with such a high density of points.

Table 1: Please standardize the notation of the coordinates in either uppercase or lowercase letters (WGS or wgs).

The methods in the paper are novel and the data is well presented.  The data set is complete and of high quality. It is useful for other researchers to use.

I would only recommend changing certain colours in figures, particularly yellow. 

The study entitled “One year of high frequency monitoring of groundwater physico-chemical parameters in the Weierbach Experimental Catchment, Luxembourg” by Karl Nicolaus van Zweel et al. presents a dataset resulted from a year-long field measurement campaign of groundwater physico-chemical parameters (electrical conductivity, dissolved oxygen, oxidation-reduction potential, and pH) in the Weierbach Experimental Catchment (Luxembourg).

The laborious methodology applied to monitor the groundwater parameters, as well as the presentation of all equipment used, protocols and techniques of water sample measurements and analyses are well described.   

Below are few specific comments:

In the section 2, a detailed description of the forest vegetation (tree-species distribution, percentage of the forest cover within the catchment, tree density, etc.) is incomplete. This detailed description would allow the reader to get a clearer image of the study area in which the groundwater was monitored. A forest map would be also helpful.

Lines 60 -65: You should provide here the scientific name for all the tree and shrub species mentioned in the text.

Figure 1 (a): Contour lines are drawn on the map, but without altitudinal values; at least in the case of the main contour lines (5 m), the altitudinal values should be provided.