I made an aquarium with greenhouse that you don't have to worry about, The fish are fed automatically, the water is filtered and heated, the greenhouse is cooled and much more And of course there is also an app with a bluetooth connection. I automate the following things using Grove sensors and actors.

Is the intention to automate the existing aquarium with plant greenhouse. This automation is understood to mean several things. There is a continuous control of the water level in the aquarium. In the event of a leak, this is communicated to the user via the mobile phone. The turbidity of the water is also monitored. If this water becomes too cloudy, this will be communicated to the user via the mobile phone. At this point, the filter will start to operate continuously. If the water is not too cloudy, the filter is controlled via a clock so that it is not in continuous use.
The fish are fed by means of a food drum that is controlled by a stepper motor. This is also done via a time module. If the food box is empty, this is also reported via the mobile phone. An air pump provides the necessary oxygen in the water. This air pump is in continuous use.
An LED strip will ensure that the aquarium is lit between eight o'clock and sixteen o'clock if the light intensity in the room is too weak. If the aquarium is lit, this is also reported on the mobile phone. When the temperature in the greenhouse exceeds a certain value, a fan will provide the necessary cooling. The humidity is also measured. Both values ​​(temperature and humidity) are displayed on the mobile.
A bluetooth wireless communication system will take care of the communication between the Arduino and the GSM. The necessary data can be forwarded via an application (MIT app inventor) and made visible on the mobile phone.
if you have any questions or want to read my arduino program, don't hesitate and ask your question.