Security of ESP8266, relays and 230V connection in aquarium control

Hi,
I have built myself a simple aquarium control device for 4 230V sockets and some sensors. I have been using this for a good 2 years now in combination with my own API server. I wanted to update the program a bit to get rid of the proprietary solution with the API and possibly combine it with homeassistant or make it completely standalone. I still have in the back of my mind whether this is definitely safe in its current form and whether to change something or completely let go and buy a ready-made solution. I'm hoping for some advice.
I'm most puzzled by the wiring itself and the ESP power supply (It's connected via a USB cable to the charger - the black bundle in the middle of the sockets).
I'd be grateful for any suggestions.
Sorry about photo #3 - it's out of date. The hdc1080 sensor is now out of the box and the temperature probe is plugged in and out of the box.
Link to project github

I am not that advanced. That's why I'm asking what to change. No, it's not a mistake, I did it according to another online tutorial which explained that it doesn't really matter which cable to switch off. I can honestly say that it doesn't make much difference in my current situation either, because I bought a flat where the electrician flew hard and the cables in the sockets are sometimes like this and sometimes like that and the earthing is not connected at all. But I haven't found anyone who can explain to me why instead of connecting 0 to the pin the cable can be cut off at the panels. I would love to rip everything out and put it back in, but it's not that easy.

wojtaszek171 wrote:

is it really safe

You have used one of the more rubbery words. Only "ecology" is more deceiving.

safe in the sense of protection from shock
safe in the sense of hacking
safe in the sense of .... I don't know ... paying the electricity bill and boiling the aquarium ...
in the broader sense: does it not contain gross errors in the art which may render it inoperable / less functional

Added after 1 [minute]:

So it is somehow the case that for clearly stated criteria / goals comes an adequate and satisfactory solution, for lack of assumptions (vague) no solution is so.

Here you go. I mean: safe as far as electrocution is concerned and from a fire caused by a short circuit.

As a general rule, a device should be safe in all foreseeable situations. Seemingly the matter is simple, but the average designer can foresee only the most obvious situations. For this reason, the way safety is tested has been formalised. The standards that define how this should be done in practice are, for the most part, a very, very, very long checklist . It is based, among other things, on the findings of thousands of different accidents. The equipment, including its instructions, is tested. What is important is how the product will be used.
Imagine a situation like this. During some work on the aquarium, something falls out of your hand and into the aquarium. Some water splashes out. The sockets are splash-proof but you have muddled up in such a way that water gets in. The whole thing sits on a flat table water can collect on it. Will it be safe to wipe it off ?

Ok the question is generally about the device itself. Is it safe to use such relays and run the cables in the box or could unwanted surges occur. Water will not get in because all 4 sockets come out together when unscrewed. They are connected with silicone.

I understand. Good point. I'll check how it's wired in the wall socket and swap if necessary. Generally you know, things are often done in the aquarium with the lamp and heater on. .

wojtaszek171 wrote:

Water will not get in because all 4 sockets come out together when unscrewed. They are connected with silicone.

The openings of the sockets in the photo are facing upwards. If I pour water over them, will it not run inside ?

TvWidget wrote:

wojtaszek171 wrote:

Water will not get in because all 4 sockets come out together when unscrewed. They are connected with silicone.

The openings of the sockets in the photo are facing upwards. If I pour water over them, won't it flow in ?

- Of course water will flow in there, after all the plug is not with seals.
- Also, this power supply in the socket is a failure
- No fuse
This is so quick.