Hey simon, Yep correct i had thought that through evaporation, the tds will drop than with a top up it may drop further due to dilution. (Just thoughts that i had,sounds stupid but i just had to ask). Thank you for the gravy analogy, i understand what zoidburg, jayc and urself are explaining even more clearly now. Nothing can beat a water change and like what jayc said, if its bad, sometimes you just need to go and do that big water change. Solid salts can only be greatly reduced by the water change there is no other way i guess. This thread really addressed my questions on water changes and parameters. I feel that after mastering to maintain the paraneters that works for your shrimp, next would be to tether and plan water changes. I will not be able to figure anything out had no one replied to this thread, one cannot plan a schedule of water changes if one does not understand the physics behind parameters. Things havent gotten horribly wrong yet, will monitor the conditions. Keeping to 1litre water changes weekly. But now that i am more educated on how all of this works, the min things change, i am prepared to do that big water change. Ps: yep you were quite spot on my tank capacity! I have a next very impt question. Will start a new thread. Kind of like a btb(back to basics) I only have this tank and i had thought that tetras could be kept together with the shrimps, thank heavens i removed them before the babies hatched. Anyways this tank was cycled in a way that was the best i understood how(did not find this helpful forum here than), it was so rushed! My question would be how to properly cycle a tank, shrimp specific tank. (The long fishless cycle, i rather wait)I do not see good articles online. Thanks again everyone. [emoji178] Hope everyone had a great monday. Sent from my SM-N950F using Tapatalk