If one is intelligent about this, knows what he/she is doing, one can end up with quite an elegant and cost-efficient solution.
I mean, if the PV panels are not over-sized, the batteries chosen are true-deep-cycle (not taking the vendors words for it but getting the market verified number of cycles @ 80% DOD), also sized to power only the loads that need to run overnight and not the lights.
It is not that difficult to build such system - I can help with specs, sizing and product selections - there are number of very good direct-to-public importers of components, buying from them will definitely ease the pain and the reduce the damage.
Many will be surprised how little the aquarium water pumps consume - 600 lph will draw 10-15W @ 12V. Larger ones will draw proportionally more
The heaters are cycling, albeit quite power hungry, they do not consume that much energy overnight, assuming the summer ambient temperatures - I am not too sure what the difference between summer and winter cycles will be.
The idea is to set the PV panels power directly the lights, without any storage or conversion - assuming one uses high luminous flux (>100 lm/w) DC lights, the required size of panels would not be that much - read up on PAR lighting etc to determine the right luminous flux, spectrum, then based on the chosen lights, calculate the required wattage. With this arangement, being DC only, one also would not need to buy a powerful DC/AC inverter
The batteries then will only be needed to store the energy required to power overnight the pumps (very little needed) and the heater (also very little needed) - hence small part of the PV panels capacity must be used to charge the small batteries.
I mean, if the PV panels are not over-sized, the batteries chosen are true-deep-cycle (not taking the vendors words for it but getting the market verified number of cycles @ 80% DOD), also sized to power only the loads that need to run overnight and not the lights.
It is not that difficult to build such system - I can help with specs, sizing and product selections - there are number of very good direct-to-public importers of components, buying from them will definitely ease the pain and the reduce the damage.
Many will be surprised how little the aquarium water pumps consume - 600 lph will draw 10-15W @ 12V. Larger ones will draw proportionally more
The heaters are cycling, albeit quite power hungry, they do not consume that much energy overnight, assuming the summer ambient temperatures - I am not too sure what the difference between summer and winter cycles will be.
The idea is to set the PV panels power directly the lights, without any storage or conversion - assuming one uses high luminous flux (>100 lm/w) DC lights, the required size of panels would not be that much - read up on PAR lighting etc to determine the right luminous flux, spectrum, then based on the chosen lights, calculate the required wattage. With this arangement, being DC only, one also would not need to buy a powerful DC/AC inverter
The batteries then will only be needed to store the energy required to power overnight the pumps (very little needed) and the heater (also very little needed) - hence small part of the PV panels capacity must be used to charge the small batteries.