Originally Posted by AaronT
More frequent water changes also helps to keep algae spores at bay.
Every tank I've seen that has an auto water change system is more forgiving and the plants grow like mad.
I have one client who has about 10% per day done on automation, generally about 1 hour after the lights come on, then doses CO2 and Excel....as a back up.
The Dosing tanks are 2 x 5 gallons and then 2 x 2.5 Gal back ups.
Carbon block for the tap.
This system has run for about 2 years now.
I come about once every 4-6 months and trim the tank. It's never had any algae issues nor was cleaned. Just fed the fish, algae magnet the front glass once every month or so.
I tend to do my water changes large and frequent in the morning maybe 1 hour after the lights come on. Add ferts back right away etc.
Mad pearling later at night.
This pearling is not on the glass, heater or any other equipment/non live material.
I can easily fluff the bubbles off about 1 hour after the water change and they do not come back(these are degassing bubbles due to high pressure and temp).
At higher pressure and lower temp, the CO2 is higher than at ambient.
If you take this tap water and let it sit for a few minutes, warm up and depressurize........ the CO2 and O2 will escape.
Same for the aquarium.
I think perhaps Ole's work with gas films might apply a bit, it would increase the rates. If you doubt that water changes influence growth rates in your aquarium: a simple test: do water changes daily about 1 hour after the lights come on, say 40-50%. Do this for 1-2 weeks and then do do ANY for 1-2 weeks. See what you think. One day may be hard to tell the differences.
O2 meter does not lie as far as plant growth near the end of the day. It's always higher the day of the water change.
Since I do the water change early on, then 6-7 hours later, the O2 reading is taken.........a direct relationship with the tap is not likely, I also have wet/dry filters which should remove some of the excesses/degassing from the tap, leaving mostly only plant growth production left.
7. Bacterial and periphyton films. As these are exposed to air during the water changes, or high rates of micro bubbles and dissolved air/gases etc..........the bubbles will adhere. They will provide these films with brief high levels of O2, increasing respiration. Some of the surface tension will stick and pull off a lot of these films on plant leaves....... leaving a cleaner plant leaf behind. In the next few hours, the leaves will be recolonized again. This reduces the barrier and increases the Flux across the leaf for nutrients and CO2, light etc.
This may tie into the CO2 mist Hypothesis effect, the mist itself may be doing a cleaning action on the plant leaves.
A water change may also do a very similar thing.