You can use tap water but just be aware of the fact that it is the carbonates/bicarbonates in tap water that eventually wear out the buffering ability of the substrate, which in turn will cause the pH to slowly rise until it finally settles at your tap water's nominal pH. How long this will take will depend on KH fluctuations with your tap source. It could be anywhere from a couple weeks to a year. You could purchase some distilled water to use for top offs and water changes (when remineralized of course). It's cheap and readily available. You don't need to change much water out of a caridina tank anyways... like 10-15% a week at most. Using distilled water will help to prolong the longevity of your substrate's buffering, which will keep parameters at ideal range for these shrimp. No need to buy an R/O unit for a 10 gallon tank anyways.

I use SS GH+ as my remineralizer as well and it's great for using with RO/DI or distilled water. I use at the rate of 1/8 tsp per gallon. This gives me a TDS of roughly 100 and a GH of 4-5 degrees, which is just about perfect for CRS and other bee shrimp. You won't need to add this GH+ to your tap water since you are already in the 4-5 dGH range. Just remember to top off evaporated water with distilled water only.

 

I’m going to do a 50% water change on my 10 gallon tank that I plan on adding crystal red shrimp too. Right now my TDS is at 220 for the whole tank and GH is at 4. Will doing a 50% water change when I take that out halve my TDS and make it 110 TDS (which is what I want)? Also, when I remineralize the distilled water that I decided I will use (bought 5 gallons the other day) and get a GH of let’s say 6, and a TDS of 150, is that what my water in the tank will be once I put it in, or will it add on top of the already existing TDS and GH and make it 370 TDS and 10 GH? Basically what I’m asking is, will remineralizing the distilled water and getting desired TDS and GH result in the same parameters in my tank once I add it even though their it is half tap water?

 

Is your KH 1 from tap? Or is that what's in your tank? You can use 10 ml of water and test the KH. 1 drop = 0, 2 drops equals 1. In this way, you should be able to figure out if your KH is 0 or 1. (much harder to see color change at 10 ml of water though) If it's from your tank, disregard. KH from your tap is more important to know.


I go to Walmart and fill up 5 gallon buckets with the Primo water for 30 some cents a gallon. Some people choose to buy distilled water already in a container.

 

You're taking 50% of the water and the minerals along with it. If your tank's TDS is at 220 with a GH of 4 dGh, adding 50% pure distilled water will cut both those values in half. If adding 50% remineralized distilled water with a GH of 6 to your tank, you will end up with a GH of probably around 5 degrees and a TDS of ~ 200 ppm depending on what the actual TDS of the remineralized distilled water is.

 

Ok so would you say I’m better off emptying all of the tap water I have in it right now and adding all distilled water instead 50tap/50distilled? This way I can have full contol of all parameters? No shrimp are in it yet and I don’t plan on getting CRS until I have all the parameters stable and know what I’m doing. Also if I was to do a 100% water change and add only distilled water, how many scoops of he Salty Shrimp GH+ would I need to add to the 10 gallons of distilled water in order to get my GH to 5-6 and my TDS to 90-120?

 

Yes, use distilled water for top offs because water evaporates and leaves all the minerals behind. Water changes are removing those minerals, therefore they need to be replaced. Plants also consume these minerals in small amounts, so it is a good idea to do small weekly water changes to keep these minerals replenished and in their correct ratio. I never understood how some people are able to get away without any water changes at all in their caridina tanks. They must not have any plants other than a few clumps of moss.

You should be fine draining your tank with plants in there. I've done it a few times myself. Some plants don't take well to drying out in the air, so it's best to not stall on refilling the tank for too long. If you have a lot of rearranging to do, you could mist the sensitive species with some water in a pump sprayer until you are ready to flood the tank.