Thoughts

I have been thinking and I have an that I want to put out there and see what everyone thinks.

This setup will be on a 120 gallon with a 40 gallon sump.

If I was to set up a holding drum/tank of pre mixed saltwater with the same salinity and temp as my tank, could I set up a double dosing pump at about 1 and 1/2 gallons per day to pump water out of my tank into a waste drain, and have the same rate pumped into my tank from the holding tank of pre mixed water and not have to do water changes. This would come out to be about the equivilent of a 45 gallon (33%) water change every month.

I would still have to run an ATO for evaporation.

Any thoughts or forseen issue?????????????????????

 

sounds like a well considered idea to me Tony
couple of things to consider

1) ensuring the containers are food grade would be ideal as certain plastics can leach phosphate
which is not normally a problem if the bucket in question was holding water for 24 hours prior to a water change but could be an issue with long term storage of the new water

2) certain salt mixes have organic compounds such as vitamins in that break down , these then naturally trigger a nitrogen cycle and as the bucket/ holding tank might not have adequate real estate for bacteria required to process these organic compounds, you may be adding water containing ammonia / nitrite etc to your aquarium - suggest a dry run, before hooking up to your reef tank, allowing the water to sit and circulate and then monitor levels in there before hooking up
not all salt mixes do have these, so a bit of research and a test run using your chosen salt mix circulated in a food grade bucket for a couple of weeks would be a good idea

I cannot think of any other negatives at this stage other than covering those containers
so that light does not encourage algae in there and that air borne polutants and not carried into the container

hopefully someone else will cover anything I overlooked

hope the above helps


additional research done
Instant ocean does not have organic included
Reef Crystals does
so using Instant ocean and then manually increasing your Calc,alk and Mag to bring them in line with your target parameters may be a good solution in addition to saving you a few cents in the gallon

stored for a long time, with Reef Crystals you could experience bacterial activity
but providing you dont get cloudy water as a result and your test kits come back with 0 on ammonia and Nitrite - then the water is perfectly safe to use

Steve

 

Id be primarily concerned with maintaining salinity. Its near impossible to pump in exactly what you pumped out. Even with the same pumps there different friction losses, head losses, and even the pumps themselves..