Aerobic Septic Tabs Being Consumed Quickly?

I have an aerobic septic system at the house I just bought. It's fairly recent, or at least the seller's disclosure indicated the first stage had been replaced in the last several years. It's a spray-discharge type.

When I moved in, I noticed the chlorinator tube was empty, so I filled the cartridge/sleeve with 3" Pro Chlor tabs. I don't remember exactly how many it held, but it was probably around 15-20 tabs.

We are only there on the weekends and do not have a clothes washer, so most water usage is just from the kitchen sink, dishwasher, toilets, and showers. Our family consists of 2 adults and 2 younger children.

After the first 6 weeks, I checked the chlorinator tube again and it was already empty!

Is it normal to go through the tabs that fast?

Is it normal to have a small amount of standing water at the bottom of the chlorinator tube? I would think water would only move through the chlorinator when the solids tank is overflowing to the aeration tank, and hence only use chlorine during that overflow period. Or maybe it's when overflowing from the aeration tank into the pump station? Am I wrong?

Lots of websites say to only add 4-6 tabs at a time to the cartridge/sleeve and never to fill it all the way up, but the Pro Chlor bucket says to fill the cartridge all the way. If the system is working the way I expect, it should consume the chlorine as-needed, and if you use up all of the chlorine tabs in the cartridge/sleeve, you are possibly not effectively chlorinating/disinfecting the effluent. Am I wrong?

Thanks!!

I have an aerobic system also.

I can only tell you my experience, which is that no matter how many tabs I added, they all dissolved within a week or two. I had to add a tab each week.

So I had a liquid chlorinator installed. I now add a gallon of bleach every two months.

Thanks for your reply. When I went out to the house last, after having not been there for 2 weeks during which time the water main was shut off, I noticed there was still standing water in the chlorinator tube.

So this means that no matter what, those tablets are going to dissolve.

For now I'm just going to drop two tablets in there whenever I go to the house, which would be 2 tablets per week, or less.

I am concerned though, since the water is standing there which I presume is the overflow between the aerobic tank and the pump station, that the chlorine is dissolving into both sides, which would decrease the effectiveness of the aerobic process.

I'm going to call a septic guy and have him come out to check everything and make sure my understanding of this system is correct, since it was already installed when I purchased the house.

Never heard of chlorine in a septic tank. Around here we tell our customers “no bleach”. But anywho. Our pool eats up chlorine tablets like me with honey buns lol. I would go with the other guys suggestion of a chlorine pump for liquid. Less hassle.

Aerobic systems with a sprinkler field require hypochlorite to disenfect the effluent before spraying. Otherwise you will contaminate lakes and rivers with run-off, and this property is directly on a lake, hence my concern.

It's a different kind of chlorine tab than used in a pool. It's non-stabilized and highly reactive. It's designed to dissolve very quickly, unlike the di-chlor or tri-chlor tabs used in pools.

My concerns are two-fold: the standing water between the aeration tank and the pump station, causing the tablets to continually dissolve; and that the dissolved chlorine is spilling into the aerobic tank, which would be quite detrimental to the aerobic process.

Sounds like you might need to pay that service charge for the local specialists on this. Call the septic supply shop in your area. Ask that person who they would have service their system. But sounds like you might have answered your question. If a pool uses “stabilized” tablets and yours are designed to dissolve quickly. I really don’t even know why I got involved at this point. Must have been the coffee. Your good to roll your eyes and ignore me. Lmao