The best pH for a betta is around 6.5 to 7.5, close to neutral. That said, a betta cares far more about a stable pH than a perfect one, and chasing an exact figure with chemicals does more harm than the reading you are trying to fix. Bettas are farmed by the million across a wide range of water and adapt to most steady conditions, including hard, alkaline tap like mine. ...
Neocaridina cherry shrimp do not need a heater in a normally heated room, because they are comfortable anywhere from about 18 to 26 degrees Celsius. If your room sits reliably in the high teens or low twenties, an unheated shrimp tank is fine, and I run several of mine that way. A heater becomes worth adding only when the room gets genuinely cold or swings sharply between day and night. ...
A 10 gallon tank, which is roughly 40 litres, comfortably holds a single shoal of six to eight neon tetras and nothing else. Neons are shoaling fish that need to be in a group to feel secure, and six is the sensible minimum. Eight is better still. That group fills the tank on its own, so resist the urge to add a second species alongside them. Free PDF ...
Ragged fins are one of the first things a new keeper panics about, and fin rot is usually the diagnosis they land on, sometimes rightly. I have dealt with it more times than I would like, mostly in my early years when my water changes were casual and my tanks were more crowded than they should have been. The good news is that fin rot is rarely a death sentence and almost never a mystery. It follows poor conditions the way damp follows a leaking roof, and once you understand that, the fix stops being about chasing a magic bottle and starts being about the water. This is how I recognise it, treat it, and keep it from coming back. ...
If you keep hard tap water and you want a splash of colour that will not sulk in it, Endler’s livebearers are one of the best small fish you can buy. I picked up my first group almost by accident, a handful of unlabelled males in a bag from a local keeper, and they turned a quiet 40 litre into something that stopped visitors mid-sentence. The males look like someone dipped a guppy in metallic paint and then shrank it. They are cheap, hardy, endlessly active, and they thrive in exactly the water that makes soft-water darlings like cardinal tetras miserable. This is how I keep them, what they actually need, and the one habit that will save you a lot of grief later. ...
Of all the clean-up animals I have kept, the nerite snail is the one I recommend without hesitation, and it happens to be a perfect match for hard tap water. Most freshwater snails simply tolerate the minerals in hard water; the nerite depends on them. Those minerals are what keeps its shell hard and smooth, so the very water that troubles soft-water fish keepers is a gift to nerite keepers. If you have algae on your glass and hard water in your tap, this little snail is about as close to a purpose-built solution as the hobby offers. ...
If your tap water is hard and alkaline, and a lot of ours is, the molly is close to the ideal fish. Most of the popular community species were bred for softer, more acidic water and only tolerate what comes out of my tap; the molly actively wants it. Warm, mineral-rich, slightly alkaline water is exactly the environment these fish evolved in, so for once the water that fights you with tetras and rasboras is working in your favour. Here is how I keep mine, and where people go wrong with them. ...
The ideal GH depends on the shrimp: Neocaridina, the common cherry shrimp and their colour forms, want a GH of roughly 6 to 12 dGH, while Caridina, the crystal reds and bee shrimp, want it far softer at around 4 to 6 dGH. GH matters more to shrimp than almost any other reading, because shrimp build a fresh calcium-rich exoskeleton every time they moult, and the water is where that calcium comes from. ...
For most tropical tanks in a normally heated room, size an aquarium heater at roughly 1 to 1.5 watts per litre. A 60 litre tank wants somewhere around a 75 watt heater, and a 100 litre tank a 100 to 150 watt one. That guide keeps the water at a stable tropical temperature without a heater that runs flat out or one that never keeps up. Free PDF ...
A general community tank is happiest at a stable pH anywhere between 6.5 and 8, and holding that number steady matters far more than hitting any exact figure. Almost every fish sold for a community aquarium is farm-bred and many generations removed from the wild, so it adapts comfortably to a wide band of pH as long as the water does not lurch about. A rock-steady 7.8 is far better for a shop-bought tetra than a tank that swings between 6.5 and 7.5 because someone keeps dosing it. ...