You can pick up a good TDS meter on amazon for less than 15 dollars, I would highly recommend having one for the future. You want to measure the TDS of the water you are using for water changes, then the TDS of the water inside the tank. If your TDS was 358 before the water change and 108 after, you must have changed like 50% of the water and the TDS of your tap water must have been close to 0. Are you using RO? The TDS of your tank, if you are doing regular water changes and you do not have too many rocks inside your tank, should not be too much higher than your tap water TDS.
Also it is not a good idea changing the parameters in a tank that quickly, this is what kills fish and shrimp most of the time, so be careful.
TDS will slowly rise over time and daily as water evaporates.
theres no rocks in it, its just eco-complete, a piece of driftwood, a few mosses, a anubis, and a piece of PVC
i use RO on all of the my tanks.
Originally Posted by somewhatshocked
Dropping TDS from 358 to 108 instantaneously means a TON Of hardness was removed. Reduced it more than 3 times. That could lead to molting issues and death. 358 to 108 is not subtle.
People use RO/DI water that is remineralized and they don't alter parameters so quickly. If you must alter parameters, you do so aiming for specific measurements and you do it slowly, over the course of several days or - at a minimum - several hours.
thankfully there is just a few chili rasboras in there keeping bacteria alive. my goal was and is to see where my tank sits naturally, and stick to those parameters. i tend to get lazy and don't want to try to do something i might get lazy and stop doing right.
RO is popular because the people who use it successfully understand NOT to allow such a big drop all in one go.
To change a tank's mineral composition so drastically they take time, a little today, a little more in a few days, more next week. Over perhaps a month they can take a hard water, high TDS tank down to a fairly soft water tank.
Then use a blend of RO and tap to keep it that way.
DO NOT hold off on water changes, allowing the water chemistry to gradually change, get harder, then hit it with a giant water change that drops everything back to 'perfect'.
I don't normally make that sort of mistake. at that moment i was so focused on how high the TDS was. when i'm doing things right i do my weekly 30% WC on all my tanks, but this tank is new to me and half the time is hidden behind my bathroom door (gotta leave it open because the litter box is in there).
but regardless that tank is back to being on the the WC schedule that the rest of the tanks are on, as this week was 50% water change week.
but since i have mentioned it. 50% wc on a specialty shrimp tank is not a good idea then huh?
the TDS has settled in the 140 range, so i can assume that i have a TDS of 140, and just need to figure out how to keep it in that area? or should i wait another week because the large wc has more than likely really thrown off things?