Monitorizăm amoniacul după schimbul de apă.

In Romanian, the verb ending often shows who is doing the action, so the subject pronoun can be left out.

• monitorizăm = we monitor
• the ending -ăm marks 1st person plural in the present tense for this verb

So Monitorizăm amoniacul already means We monitor the ammonia.
You could add noi for emphasis:

• Noi monitorizăm amoniacul. = We monitor the ammonia.

But in normal speech, noi is usually unnecessary.

The base form is a monitoriza, which means to monitor.

A few present-tense forms are:

• eu monitorizez = I monitor
• tu monitorizezi = you monitor
• el/ea monitorizează = he/she monitors
• noi monitorizăm = we monitor
• voi monitorizați = you all monitor
• ei/ele monitorizează = they monitor

So monitorizăm is simply the we form of a monitoriza.

Because Romanian usually adds the definite article to the end of the noun instead of putting a separate word like the in front.

• amoniac = ammonia
• amoniacul = the ammonia

That -ul is the definite article here.

So:

• Monitorizăm amoniac would sound incomplete or unnatural in this context
• Monitorizăm amoniacul = We monitor the ammonia

Schimbul is the definite form of schimb:

• schimb = change / exchange
• schimbul = the change

In this sentence, Romanian uses the definite form because it refers to a specific event or process: the water change.

So:

• după schimbul de apă = after the water change

You may also hear după un schimb de apă if someone means after a water change in a more indefinite sense.

Here de apă means of water or more naturally in English, water as part of the phrase water change.

• schimb de apă = literally change of water
• natural English equivalent: water change

Romanian often uses de + noun to link two nouns in this kind of expression.

So schimbul de apă is the normal way to say the water change.

Using apei would suggest a different grammatical structure, and it is not the usual phrasing here.

După means after here.

So:

• după schimbul de apă = after the water change

It usually refers to time or sequence in this kind of sentence.

Some examples:

• după masă = after the meal
• după curs = after class
• după schimbul de apă = after the water change

The given word order is natural and standard, but Romanian word order is fairly flexible.

The basic sentence is:

• Monitorizăm = verb
• amoniacul = direct object
• după schimbul de apă = time phrase

This order sounds very normal:

• Monitorizăm amoniacul după schimbul de apă.

You could also move parts around for emphasis, for example:

• După schimbul de apă, monitorizăm amoniacul.

That still means the same thing, but it emphasizes after the water change.

Amoniacul is the thing being monitored, so it is the direct object.

In this sentence, the form of the noun looks the same as the nominative/accusative definite singular:

• amoniacul

Romanian does not always visibly change the noun form for the direct object, especially with inanimate nouns like this one. The sentence structure tells you its role:

• Monitorizăm = we monitor
• amoniacul = the thing we monitor

So even though there is no special extra ending for the object here, it is still clearly the direct object.

It is a normal, usable Romanian verb, but it is indeed a more modern, international-type word, similar to English monitor.

In everyday Romanian, especially in technical, scientific, medical, or aquarium-related contexts, a monitoriza is very natural.

Depending on context, Romanian might also use other verbs such as:

• a urmări = to follow, keep track of
• a verifica = to check
• a măsura = to measure

But in a sentence about checking ammonia levels over time, a monitoriza is a very good choice.

The ă in monitorizăm is a very common Romanian vowel. It sounds like a short, neutral vowel, somewhat like the a in English sofa, but not exactly the same.

So monitorizăm is pronounced roughly like:

• mo-ni-to-ri-zăm

The last syllable is important: -zăm, not -zam.

If you're learning pronunciation, it helps to notice that Romanian spelling is usually quite regular, so once you learn sounds like ă, reading becomes much easier.

Yes, depending on context.

Romanian present tense often covers both:

• We monitor the ammonia
• We are monitoring the ammonia

So Monitorizăm amoniacul după schimbul de apă can be understood either as:

• a general/habitual action: We monitor the ammonia after the water change
• an action happening now, depending on context: We are monitoring the ammonia after the water change

Romanian does not require a separate verb form the way English distinguishes monitor and are monitoring.