@Miniandy thank you
🙂
@Connswater
- interesting, why should getting rid of the skimmer help? I thought its pretty important to have clear surface without scum to help with gas transfer (oxygenation)
- I have 3 mollies, they dont seem to do much damage to the algae 🙂
- How should the sand help? I would worry that over time it would mix with aquasoil and make a mess + it would worsen the (perhaps already not great) flow in the soil
All good questions, and my answers may not be totally satisfactory.
I personally don't like skimmers, I do ripple the surface with my filter output, sometimes with a lily pipe across part of the tank surface for adequate O2 exchange. Skimmers however, unlike the outflow of the filter block up with immature floating plants and are not normally used with floating plants, which of course makes them really handy for getting rid of duckweed. They can suck in fry, my mollies are self-sustaining. I like my tanks to have a relatively peaceful undisturbed surface on some of the tank, with the meniscus unbroken and spring tail colonies existing. Fish fry feed on the immature spring tails. Adult fish feed on mature spring tails, useful when I am on holiday. I think, a balanced surface, some movement some still water, is more natural, pond like, with less CO2 lost, but oxygen exchange on part of the surface. Some of this helps with algae control, that is harvesting floating plants, the nutrients they export, the shade they provide, the reduction in CO2 lost, and floating plants are good indicators of nutrient deficiency - the 'duckweed index', I've generally seen skimmers used on tanks with a clear surface. If you pump in enough CO2 I am sure skimmers have something to add to the environment for fish and rooted plants, but 10 years ago, I don't think anybody used one and I tend to be a bit of 'old time' fish guy. I've used them, and electrolysis devices, I personally haven't found either helpful but floating plants are, I find, the main way to keep a planted tank manageable and healthy. Floating plants do wonders for water quality and if the tank isn't open i.e. has cover glass, with floating plants, water top ups and water changes can be significantly reduced, I have to mix rain water with my tap water, so I don't want to do lots of water changes.
Mollies. Depends on the size of the tank and numbers, I have a dozen adults in a four foot, and many fry and immature fish. But mollies are no magic solution to algae, in my experience no livestock is, though an old friend had an algae, and plant free tank, thanks to a fairly large pleco. Mollies do graze continuously on fresh algae and Rosy barbs will eat BBA, the only fish I have found that will. In my experience shrimp need to be almost in plague proportions to really impact algae, this happened to me with cherry shrimp in an office tank some years ago. I think, mollies help prevent plants getting covered with algae, nipping it, sort of, in the bud, they don't impact upon well established algae. But I cannot scientifically prove it.
My main tank is mainly horticultural grit, it is too large in particle size to stop plant tabs leaching quickly, but fine enough for plant roots, a covering of silver sand seals the surface I think, to some extent, reducing the speed of water column fertilisation. A sealing probably works best on soil, on even fine gravel it will eventually settle down to the bottom, but then it still serves as a burial material for root tabs. Sand is also very much favoured of course by corydoras species, who blow it out of their gills constantly, moving it and thus keeping the surface relatively clear and green algae free.
