Hello Andrey, A water change of 10% - 15% per week will not cause any deterioration in your tank. The fish are going to benefit from this with an improvement in their growth and activity. If you feel that you would rather carry out smaller water changes on a daily basis then this would be ideal. Add a dechlorinating agent to the water to be added to tank. You mention that the Labeo attacks the Rams, this being the case I personally would remove any fish in any of my tanks that attacked any other fishes. Ramirezi average size would be 3 inches. Good luck, Helen >I've thought about water changing, but I fear that this can cause some >deterioration of the >anything? And I suppose also that everyday or so gradual change is better >than weekly. Am I right? > the tank and a Labeo of approximately the same size even attacks them... >- Andrey ------------------------------------------------------------------------- This is the apistogramma mailing list, apisto@majordomo.pobox.com. For instructions on how to subscribe or unsubscribe or get help, email apisto-request@majordomo.pobox.com. Search http://altavista.digital.com for "Apistogramma Mailing List Archives"!