If i understand correctly, you have a salt based water softener on your well water. Isn't this what comes ouy of the tap? If so, then I would not use it. The reason is the sodium in the water from the softener. This does not show up on either GH or KH tests. However, it does contribute to conductivity/TDS which is a better measurement of what is in water than either GH or KH. Most freshwater fish do not do well with much sodium or salt (sodium chloride) in water. Rift lake cichlids are the exception.
Do you have access from any outdoor or indoor faucet that delivers well water that has not been run through the softener? If so, test that and report the numbers here. It is easier to deal with hard water than salt (sodium) water in your situation.
I assume the numbers you gave for GH and KH are ppm. What follows below is from the FINS site
https://fins.actwin.com/aquariafaq.html
General Hardness
0 - 4 dH, 0 - 70 ppm : very soft
4 - 8 dH, 70 - 140 ppm : soft
8 - 12 dH, 140 - 210 ppm : medium hard
12 - 18 dH, 210 - 320 ppm : fairly hard
18 - 30 dH, 320 - 530 ppm : hard
higher : liquid rock (Lake Malawi and Los Angeles, CA)
Softening Your Water (i.e., lowering GH)
Some fish (e.g., discus, cardinal tetras, etc.) prefer soft water. Although they can survive in harder water, they are unlikely to breed in it. Thus, you may feel compelled to soften your water despite the hassle involved in doing so.
Typical home water softeners soften water using a technique known as ``ion exchange''. That is, they remove calcium and magnesium ions by replacing them with sodium ions. Although this does technically make water softer, most fish won't notice the difference. That is, fish that prefer soft water don't like sodium either, and for them such water softeners don't help at all. Thus, home water softeners are not an appropriate way to soften water for aquarium use.
Fish stores also market ``water softening pillows''. They use the same ion-exchange principle. One ``recharges'' the pillow by soaking it in a salt water solution, then places it in the tank where the sodium ions are released into the water and replaced by calcium and magnesium ions. After a few hours or days, the pillow (along with the calcium and magnesium) are removed, and the pillow recharged. The pillows sold in stores are too small to work well in practice, and shouldn't be used for the same reason cited above.
Peat moss softens water and reduces its hardness (GH). The most effective way to soften water via peat is to aerate water for 1-2 weeks in a bucket containing peat moss. For example, get a (plastic) bucket of the appropriate size. Then, get a large quantity of peat (a gallon or more), boil it (so that it sinks), stuff it in a pillow case, and place it in the water bucket. Use an air pump to aerate it. In 1-2 weeks, the water will be softer and more acidic. Use this aged water when making partial water changes on your tank.
Peat can be bought at pet shops, but it is expensive. It is much more cost-effective to buy it in bulk at a local gardening shop. Read labels carefully! You don't want to use peat containing fertilizers or other additives.
Although some folks place peat in the filters of their tanks, the technique has a number of drawbacks. First, peat clogs easily, so adding peat isn't always effective. Second, peat can be messy and may cloud the water in your tank. Third, the exact quantity of peat needed to effectively soften your water is difficult to estimate. Using the wrong amount results in the wrong water chemistry. Finally, when doing water changes, your tank's chemistry changes when new water is added (it has the wrong properties). Over the next few days, the chemistry changes as the peat takes effect. Using aged water helps ensure that the chemistry of your tank doesn't fluctuate while doing water changes.
Hard water can also be softened by diluting it with distilled water or R/O water. R/O (reverse-osmosis) water is purified water made by a R/O unit. Unfortunately, R/O units are too expensive ($100-$500) for most hobbyists. R/O water can also be purchased at some fish stores, but for most folks the expense and hassle are not worth it. The same applies to distilled water purchased at grocery stores.
End of FINS info
I use a 3 stage RO/DI (reverse osmosis/dionizing) unit. It makes pure water. It cost me about $125 years back and makes up to 75 gals/day. My brother just bought the same one but the price is now $139. I use about 11-12 gals./ week for wcs. I make it about once month and store it in 5 gal buckets with lids and 1 gal. jugs from cider bough over the years ad rinsed out well. The system came with a garden hose adapted input and I have a hose size output on my sink. It is also available so it can tap into a water line. I use a lot of hoses and pumps and most are adapted wo use garden hose connections.
https://store.afwfilters.com/revers...e-aquarium-ro-di-system-with-75-gpd-membrane/
if you are interested in looking into an RO or and RO/DI unit, which modules you will need depends on the water being filtered. Mine only has 3 stages (carbon/RO/DI) but you might need more. If I could redo it I would have a sediment module instead of the carbon. Also, you would not need a 75 gpd capacity and could go with less which could make it less expensive.
