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Discarding reef tank water into a septic system?

Coffee with Mango

Well-Known Member
BRS Member
Hi,
I am moving from a house with town sewer to a house with a private septic tank. Should I be concerned about pouring tank water into my septic system when I do water changes?
Thanks,
Holly
 
I have a septic system and have in mind he past dumped saltwater into it without much issues, I've since ran some PVC underground out to a leeching field of sorts where, when I do an occasional water change it goes.
 
This was covered in pretty good detail on R2R and some septic experts weighed in. Unless you have a 1000g tank and are doing major water changes every few days, putting waste saltwater at 1.026 sg into your septic is unlikely to have any effect on the tank or bacteria living therein.

A much larger impact are water softeners which backflow and put brine (1.2 SG) into the septic, which is illegal in some places due to its impact but that is WAY higher salinity than your tank (the brine sinks to the bottom and displaces good bacteria).

the water you dump from your 120g system will have a negligible impact on your septic performance assuming you are also showering, flushing, washing dishes and such. Your Pee can be 1.030 SG...

I have almost 400g of water volume, and dump probably 30g/week down the toilet in WC. I had my septic inspected not long ago, no issues whatsoever.

Hope that helps.
 
If you are one of the "pioneers" dumping antibiotics into your water like its 1999, then flushing that, I would think long and hard. But I wouldnt sweat the normal saltwater.
 
As others have said - do not dump saltwater into your septic! I’m on septic and did this for a bit, even with small water changes my yard would reek of rotten egg sulfur smell for quite a while after a water change. Unless your septic is huge and you’re doing tiny water changes, it will kill off the bacteria in your septic quickly. I switched to pumping mine out to an area in my garden with crushed stone.

Edit to add: my septic tank is 1500g and I still had issues. So I wouldn’t go by the >1000g septic size would be fine thoughts.
 
Very different answers from everyone. Not sure what to do. I wanted to sell the 120g (I posted it here on the marketplace, but no nibbles.... not sure what a fair price would have been). Movers come tomorrow and I have to tell them whether to move the tank or not. Blah.
 
It is all depends on how much salt water you are going to put into the septic vs the size of the septic tank.
For example, many houses have 1000 to 1500 gallon septic tanks. Assuming your reef tank is 120 gallon and you are going to change 10% per week, that is 12 gallon into a 1000g septic. That will have no impact on the septic system what so ever.
 
I've decided to stick with my 38 gallon for my reef tank and use the 120 gallon for an orchidarium (or similar).
 
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