Originally Posted by FishMad
.......Ok, this has become extremely scientifically serious. Forget about the plant issues here, I care more about the health of my fish! The plants are there for the fish to eat as well as adding a balance to the tank. At the end of the day I am less concerned about sustaining plant life and more focussed on sustaining happy lives for my fish. I really couldn't care less if my plants growth is minimal, as long as the tanks balance is right.
I am still confused about the PH issue. As I mentioned in my previous post my tap water parameters are ok except the PH. For the most part, reflecting on the water tests that have been carried out over the past 6 months, my PH seems to sit between 7.0 and 7.6. There has only been the odd ocassion that I have used the PH buffer to regulate the PH.
I am not sure I understand the reason too much o2 is detrimental to the fish........I didn't think that it was possible for them to have too much o2.
Any comments regarding the changes to the feeding schedule and behavioural changes?
OK, dealing with the pH as you request.
It should not be fluctuating in the tank to this extent (7 to 7.6). Once a tank is biologically established, and with regular maintenance (and/or plants), the pH should be stable aside from the couple of decimal points in the diurnal fluctuation. Depending upon the hardness it may slowly lower over time. Do you know the GH and KH of your tap water? The water supply folks can tell you this, they may even have a website with a list of what's in the water (mineral and such) and hardness is likely to be mentioned.
Are you testing the pH at the same time (roughly) each day you test it? You should, in order to see any pattern/changes.
Earlier you mentioned using the pH regulator [h'm, interesting name for this stuff] if the tank pH was "low" to bring it to 7. With the tap water at 7.6, is the tank pH dropping below 7? Regular partial water changes are intended to remove "crud" which no filter can, and also to maintain water stability. However, one has to be careful if significant parameter changes result.
Fluctuating pH is stressful on fish, to varying degrees on different fish. The fish must adjust the pH of its blood to equal the environment. Having to keep doing this is stressful, which is why so many of us caution that a steady pH that may be slightly outside the fish's preferred range is better than one that keeps fluctuating. I understand that a difference of a couple decimal points is not likely to be dangerous in itself, but it is the frequent or regular fluctuation up and down that will take its toll.
This hobby is about science, and you can't (nor should you try) to escape that. We are dealing with living creatures in a living environment--and a very un-natural one for the creatures. None of these fish evolved in a closed system comparable to even the largest aquarium. We must be careful what we do to this system, as a seemingly insignificant change can have serious consequences.
As for the behaviour changes, in my view the fish are beginning to act according to their environment. I can't see mention of the tank size, nor of the number of fish (may have missed it, sorry if I did), but there are some issues to be aware of with these fish. Clown loaches need a group of five or more, they have a social structure and are highly social. Aggression frequently occurs with less than 5, or in too small a tank. Angels and silver dollars I do not see as compatible fish. And you have evidence of this now. I would be less inclined to attribute this to a change in feeding and more to the natural inherent instincts and behaviours of the various fish becoming more obvious.