Addressing Unpleasant Odor from Floor Bathtub Drain in Apartment Block - No Siphon Issue

Hello, I bought an apartment in a block of flats and I have a problem with the drain of the bathtub. Sometimes it stinks from under the bathtub. Today there was a mega unpleasant smell and I decided to go for it. This is the case. The drain is in the floor. The bathtub has no siphon. I found a metal grate on the floor in the corner. When I looked at that square drain in the floor, there is water all the time. Should it be like that? For now, it is not necessary to renovate the bathroom because in the future the cooperative will liquidate gas stoves. How to temporarily fix this situation? Buy a bathtub siphon? But it shouldn't stink now anyway, because there is water in this grate.
This inclined pipe is a preview of what the drain pipe from the bathtub looks like

The fact that the water is standing still is not enough. The question is whether the drain is below the water level, i.e. is there any siphon (something in the photo is slightly visible). The second thing, the water splashes onto the spout and soaks into the concrete, as if there are no terrible impurities in the bathtub, but with time it can smell and develop fungus or mold.

I will try to feel there today whether the drain is under or above the water level.
Should I buy a grid for this hole or what should I do with it?
If the drain is under the water level, should I buy a bathtub siphon or leave it as it is?

Added after 44 [seconds]:

Luckily I didn't notice any fungus or mold there

The grille alone will do nothing in this situation. You must have adequate drainage.

And I just want to do with this ebb. So we have two options.
The first outlet from this grate is below the waterline and the second outlet is above the waterline.
What to do in both cases.
In addition, it does not depend on which case, what siphon to buy for this bathtub and what grate to buy so that there is no such big hole there.

You must have a siphon, without it it will be a sewer stench.

The end siphon with a flexible connection will solve your problem, it is flexible so you can form it according to your assembly conditions, at least for me it solved the same problem

Oki or flexible siphon. How to connect it with a hole in the floor so that it is tight and free of stench?

RPAS wrote:

with flexible connection

In such a harmonica, they like to collect muck and effectively block water. I recommend so on average. Well, unless you do not cover the bathtub and you will have free access to it to open and clean it.

I will have access, but if you have another idea, I will be happy to hear it

Added after 14 [minutes]:

Oh, and this thing about the tight connection of the siphon with this hole

Slightly tear down the floor. Discard existing siphon. Install PVC pipe, pour diamond mortar, tile adhesive with sand, etc. Place a flat bathtub siphon and attach to the bathtub. 100% guarantee that the stench will subside.

https://allegro.pl/oferta/syfon-wannowy-do-wa...98?Jfeed=aa34192d-eee2-4419-9a9a-de66b9dfae24 Przedsiębiorstwosource=google + i + zmi% C4% 99kaczacze + water, + tools% C4% 99dzia, + siphons + i + in% C4% 99% C5% BCe, + valves + and + rest% C5% 82e & gclid = EAIaIQobChMI2Kintf_I5wIVAqoYCh1iGQrxBJQYBiABD_gJQYBiABD_gJQYBDE
This is what all bathtub siphons look like, so I will have to use a flexible link anyway, because the drain is downwards.

Added after 1 [minutes]:

Such renovation works are not yet available

Each of the connectors in the siphon is rotatable, so you can fold it on the elbows so that the drain will be downwards. And looking at the whole thing from the top it will be in the shape of the letter C or V. You can go down from the siphon using a 90 degree bend or 2 x 45 degrees.

Oki, I can handle the siphon. Help me how to connect it with this hole? Any rubber reduction?

Terrible confusion! First, if there is water, there must be a siphon installed in this floor and you do not need another one. Odors can arise due to the siphon being heavily soiled and must be cleaned preferably by hand. WARNING! In my old apartment I had a similar situation and it turned out that the previous owner was throwing used razor blades on the floor and landing in this siphon, so I recommend caution. The low capacity of this siphon caused by its contamination can cause the rapid flow of the draining water to suck in too much and the siphon to open. This will open up a flow of air (stinks) from all sewerage to the bathroom and then onto the apartment. You don't have to close the holes under the bathtub, because theoretically there is fresh water all the time.

Shogun thanks for the comprehensive answer. Let me start by cleaning this siphon. And tell me vinegar plus baking soda plus citric acid is good for rinsing these pipes or not?

Caustic soda (NaOH) which is a popular mole.

Do not mix acids with hydroxides (caustic soda).

For example, first hot soda, then some acid after rinsing. Never together. You could get burned.

I will be more precise: if the drain is clogged with renovation remnants, it is acid. And it's a strong one.
If organic residues (hair, soap) are just a rule.
In both cases, it must be very careful in its application.
Leave the baking soda for other purposes, because it will not help.

I noticed that only palmus and shogum know what they are writing about, I will add from myself because I had the same and it turned out that the vent riser above me was crammed by jackdaws and draining the water in the shell sucked the water from the trough (siphon) under the bathtub and ended up springing the riser by building manager

I checked and the drain is slightly below the water level. I cleaned this siphon with my hand as much as possible, I took out a bit of muck but when entering the bathroom I still feel a slight unpleasant smell.
What agent should I use to treat this siphon to clean it of these organic residues? You write that it is alkaline, but what exactly to use?

Mole.
I was talking about it. It is a NaOH solution, sometimes in a gel version.
Pure caustic soda in a compressed solution works wonders.
Just b. Be careful with your own body when using it.
Or start with Domestos for 1.5 days and watch.

And Domestos or Mole won't eat those old pipes?

maliwat69 wrote:

You write that it is alkaline, but what exactly to use?

Go to the store and buy a popular type of decongestant - KRET or TYTAN (in an orange bottle).
And follow the instructions on the package.

Oki, I read that the mole can be used for plastic and metal pipes, not for aluminum ones. It's a block made of a large plate, so the pipes are probably rather cast iron, there should be no aluminum anywhere, right?
This oblique pipe, which you can see in the photo, seems to be made of plastic, so it should probably be ok.

In general, sodium hydroxide should not be used only for aluminum pipes, it reacts with the evolution of hydrogen. For the rest, it is relatively safe, you just need to rinse thoroughly. In contact with the body, it creates deep burns that are difficult to heal. The first sensation is slippery skin, despite being rinsed with water.

You see you wrote the first one. Aluminum was not used in the sewage system, only plastic, cast iron or stoneware.

maliwat69 wrote:

I checked and the drain is slightly below the water level. I cleaned this siphon with my hand as much as possible, I took out a bit of muck but when entering the bathroom I still feel a slight unpleasant smell

You haven't described what else you have in this bathroom. Sink with a siphon (clogged), leaking sewer pipe couplings, faulty ventilation. Check if the ventilation grille is pulling (with a candle, match or lighter). Maybe you can "on the nose" sense where it stinks from. A bad smell can persist for several hours so give yourself a hold and evaluate tomorrow and keep looking.

maliwat69 wrote:

I checked and the drain is slightly below the water level.

and so it has to be boiled with 3 liters of water and pour it into the bathtub and the creatures will die, unless it collapses from the ventilation, as my colleague writes above.
ps. You will need to clear the mole if you step into a puddle when draining the water.

It all needs to be put back together with new, good fittings (not from the market). It's best to "make" a siphon from several elbows and assemble everything on stiff pipes / elbows and the problem is solved for dozens of years, nothing clogs. Do not use any flexible connectors / accordions.

andrzej lukaszewicz wrote:

It all needs to be put back together with new, good fittings (not from the market). It's best to "make" a siphon from several elbows and assemble everything on stiff pipes / elbows and the problem is solved for dozens of years, nothing clogs. Do not use any flexible connectors / accordions.

New siphon in the ceiling? Is he supposed to cut a hole to the neighbor's floor below and put those elbows in for him? Have you read what's going on here?