# Water TDS & medications



## ROBOT (Sep 26, 2016)

I recently bought a TDS meter, I wanted to check where each of my tanks were, since i have live plants and fertilize with Micros and Macros as well as a product to replace the relevant minerals that may be stripped by RO unit. I use RO water for some of the tanks. I had noticed that as time went by my live plants seemed to be doing worse. In new tank setups the same plant really thrived, bacopa and ludwigia. After measuring TDS I began to suspect this was the problem. I have read several article that seems to support this. I have also had issue with south american cichlids which tend to like soft water and low TDS. 
I tested most of the product I use in the aquariums and found the macro(fertilizer) to be the least offensive. The worst where the medications, using a 1 gallon sample starting with RO water at 4PPM, adding any of the medications, at the prescribed dosage, raised the water TDS between 125-200 PPM. At that rate it seems like the cure may be worse for the fish than the medicine they contain. I only tested the 3 medication that I had, but my guess is they all are in a similar base compound.
I did not test the 2 liquid meds i have yet.
I has taken me several weeks to bring the tanks down to what should be acceptable levels using RO water to dilute the concentration. I have always done regular water changes every week, 20-25%, and i was shocked how high the TDS was in some of my tanks. The hard water tanks were the highest, but they started at 450ppm vs 4ppm. I use to use peat moss to lower the PH before I changed to RO water. I also read that peat moss may also help lower TDS. i never had any bad impact from the peat moss before so I am going to try it again in a couple of the tanks.
Before i had the meter i had a 20 gallon quarantine tank, I put only rams in than tank,with good structure live plants, no CO2, no other added chemistry. I ran the tank that way for 8 weeks, measuring the water quality regularly(not TDS) and saw no difference in the water quality measurements in that tank vs the others. The Rams thrived and 2 pairs even layed eggs. I slowly added CO2 and nothing changed. Then i started treated that tank like the other since there was no apparent water chemistry difference. The ram slowly died off. I never could figure out what happened.That tank now has some african cichlids in it and when i measure the TDS if was 1800ppm.
Has anyone else had any similar results with TDS and medication or other products?


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## SantaMonica (Sep 19, 2008)

If you are trying to measure TDS in the tank, then you are going to get all sorts of readings from things like food, waste, etc. You really can only measure TDS of water before it goes into the tank


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