Hi All, I was wondering if i could just run my tap water through some DI resin rather than going through the entire RODI 4-5stage process. My aim is just reduce the TDS to near enough 0 - surely everything else can be handled with a good water conditioner? Water softeners are essentially just the DI resin portion, no?
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RO or Just DI Resin
- Thread starter CJayT
- Start date
Without at the very least an RO membrane I wound't do that. You would kill the DI resin in no time. The higher your TAP TDS, the faster the resin will foul. Usually the DI resin is meant to polish the water after the RO as a final stage.
The DI resin will be exhausted and destroyed extremely quickly if exposed to tap water rather then RO water.
The tap water will contain large amounts of ions that the resin will remove and be quickly exhausted.
Also the resin will be damaged by chlorine in the water.
So DI resin should only be used after your RO system to remove any remaining ions that get through the RO membrane.
Also the bit about chorine damage is one to watch, as if your RO system pre-filter/dechlorinator gets exhausted/fails and allows chlorine/chloramine to pass through, as well as damaging the RO membrane it will also damage the DI resin filter.
You can, if you can afford it, use potassium chloride to regenerate the resin and end up with potassium carbonate in the soft water, which can be used in a fish tank, especially good in a planted tank, as plants can make use of the potassium (and some plants the carbonate as well). Cost is a major issue as potassium chloride is a couple of times more expensive than sodium chloride (as well as being more difficult to purchase) and weight for weight you use more potassium regenerating your resin than sodium, as potassium ion is heavier than sodium ion. Works out about 5 times more expensive. Whilst you might not want to use potassium for your whole house water softener, there is no reason (other than cost) you could not have a potassium based ion exchange water softener for just fish water.
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Some states/counties in USA you have to use potassium based water softeners due to their poor sewerage systems previously allowing excess sodium (in domestic waste water) out into the environment and accumulating and kill plants/wildlife. Switching to potassium chloride to regenerate the softeners, releases potassium into the environment that is at least consumed by the plants.
The tap water will contain large amounts of ions that the resin will remove and be quickly exhausted.
Also the resin will be damaged by chlorine in the water.
So DI resin should only be used after your RO system to remove any remaining ions that get through the RO membrane.
Also the bit about chorine damage is one to watch, as if your RO system pre-filter/dechlorinator gets exhausted/fails and allows chlorine/chloramine to pass through, as well as damaging the RO membrane it will also damage the DI resin filter.
Not the same. Water softeners use ion exchange resins which exchange the calcium and magnesium ions in the tap water with sodium, so you end up with sodium carbonate in the water. Brilliant for washing with soap, shampoo, cleaning etc as leaves no scum or scale BUT an absolute no no for aquatic use as the water now contain sodium. Sodium is not used, in any quantity, by flora or fauna and will accumulate in the tank. The resin is regenerated by soaking in salt solution, releasing the calcium and magnesium as chlorides in the waste water and restoring sodium back into the resin, ready to be used again.
You can, if you can afford it, use potassium chloride to regenerate the resin and end up with potassium carbonate in the soft water, which can be used in a fish tank, especially good in a planted tank, as plants can make use of the potassium (and some plants the carbonate as well). Cost is a major issue as potassium chloride is a couple of times more expensive than sodium chloride (as well as being more difficult to purchase) and weight for weight you use more potassium regenerating your resin than sodium, as potassium ion is heavier than sodium ion. Works out about 5 times more expensive. Whilst you might not want to use potassium for your whole house water softener, there is no reason (other than cost) you could not have a potassium based ion exchange water softener for just fish water.
.Some states/counties in USA you have to use potassium based water softeners due to their poor sewerage systems previously allowing excess sodium (in domestic waste water) out into the environment and accumulating and kill plants/wildlife. Switching to potassium chloride to regenerate the softeners, releases potassium into the environment that is at least consumed by the plants.
Hi all,
cheers Darrel
Could <"you use rainwater?"> It saves a lot of messing about if you have space. These are three of my five water butts.
cheers Darrel
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