Aquarium Care Cheat Sheet

I frequently have people stop by to buy fish and plants from me, and if it’s their first aquarium or they’re just getting into live plants, and they usually have similar and very good questions: What’s the best way to take care of my fish? How do I get them to have babies? What’s the trick to growing plants? Assuming my plants get growing, how do I propagate them? How does care differ for the different kinds of plants? After going full nerd on them for about two minutes or so they usually pause me and say something to the effect of “I’m going to need to write some of this down.” In anticipation of those future conversations, I bring you the Freshwater Aquarium Care Cheat Sheet, so everything you might want to know about fish and plants in a five-ish-minute read. This covers everything I sell out of my tanks, so livebearer fish and rhizome plants, stem plants and floating plants. If you’re looking for information specific to saltwater, cichlids, shrimp or carpeting plants, I would recommend looking elsewhere.

Fish

Q: How much do I feed them?
A: Feed them WELL! I usually go for as much as they can eat in ~5+ minutes. The orthodox wisdom on this is to feed them no more than they can eat in two minutes, and maybe even every other day. I’ve found this to work alright with tetras, rasboras and danios, but I find that livebearers are healthiest when they’re well fed or even a little overfed. Just like our bodies, their bodies won’t work well, either, if they live their lives on the brink of starvation. I know there may be some concerns about overfeeding causing the water to foul quicker and making more work for the owner or making the fish sick, but I’ve found that overfed fish in a slightly dirtier tank are healthier by a long shot compared to underfed fish in a pristine tank.

Q: What do I feed them?
A: Natural foods and supplement with flake foods. Again, don’t look too far from common-sense nutritional wisdom for humans: whole/natural foods are better than processed foods. I like frozen blood worms, frozen brine shrimp and frozen baby brine shrimp for the baby fish. You can find them in the freezer in the aquatic/herp section of any Petco or Petsmart, but preferably your local aquatic shop. I also supplement with flake foods. Frozen peas are also a great natural source of protein as well. To prepare them, thaw them in some tank water, hull them using a paring knife and mash them up into a paste so the bits are small enough for your fish to consume. This is also a good option if you have baby fish because some of the particles will end up being small enough for the babies to eat.

Q: How do I not kill them?
A: Have you ever heard the ironic story of someone letting a tank go neglected for months except for feeding and then clean it only to create a mass casualty incident the next day? There are a few possible mistakes that could yield this result: 1) Changing out all or way too much water. If you fish are acclimated to the dirty water but you then switch it with a bunch of pristine water, it could shock their systems enough to kill them. 2) Rinsing out the gravel with hot water and bleach. Yes, there is such a thing as ‘too clean’ when it comes to aquariums. Not only do you have item #1 in play here as well, but the hot water and bleach kill all the good bacteria that converts the fishes’ highly toxic excrement (ammonia) into a less-toxic derivative (nitrates). 3) Rooting around in the gravel too much. This could cause an ammonia spike as well since all the undisturbed fish waste is effectively locked up in the gravel, and disturbing it too much releases all of it all at once. If you want to overhaul the plants and/or decor but you aren’t able to break down the tank, it might be a good idea to do it in stages, maybe 4-7 days apart. For example: I’ll take out a few of those plants this Saturday, install that piece of hardscape the following Saturday, and plant that corner of the tank the Saturday after that. Always do these things on the front side of a water change so if any ammonia is released, some of it will be removed with the water change and your biofilters will be able to cycle the remaining ammonia.

Plants

Q: How much and what kind of light should I use?
A: Give them plenty of light. I go for 250-500 lumens per gallon at 6500K color temperature. I try to avoid Amazon and shop local as much as I can, but my favorite lights to use are the plug-in spotlights that come with a metal mounting bracket and range about $30-$40 each. I like to suspend them over an open-top tank by a chain so I can adjust the height as I want to. I would wager that they are 90% as effective as the Kessil lights for 10% of the price, and the plants don’t seem to care for one over the other.

Q: I don’t have a special plant substrate.  Can I still grow plants in my tank?
A: For sure! Just make sure they have enough light (see above) and a little liquid fertilizer. I like Seachem Flourish Excel. It has carbon plus additional nutrients and also is effective at combating algae (but not perfect). It’s way cheaper and worth the money to buy a 2L bottle of it rather than little bottles at the pet shop. (Most shops only carry the little bottles so I begrudgingly source mine from Amazon.) I routinely have people ask me if my tanks are those high-tech ones with the expensive pressurized CO2 systems, which they are not. A lot of light and a little fertilizer go a long way to creating a verdant tank as long as you’re ok with growing what happens to grow best in your tank and you’re not committed to growing any highly specific, fickle, esoteric varieties of plant.

Q: How do I grow rhizome plants?
A: One and only one rule here: don’t bury the rhizome! The rhizome is the horizontal creeping stem of the plant. Burying the rhizome will cause it to die and therefore the plant to die. Adhere to that one rule and these are really fun, perhaps the most fun out of any variety of plant. You can cable tie them to a small rock to sink them and have them grow on the substrate like any other plant. You can cable tie or super glue them to a larger piece of hardscape like a boulder or a branch and they will grow epiphytically there. You can also just wedge their rhizome down into a crack between rocks or a crack in a log and they will attach and grow there. A lot of this gives the aquarium a striking, natural look that will ‘trick’ your viewers into thinking they’re looking at a piece of nature perfectly excised from the wild rather than just the aquarium in your living room.

Q: How do I grow stem plants?  
A: I like to bundle these up in bunches of 3-10 stems depending on their size, cable tie them together, trim the excess cable tie to a length of about a half-inch and then plant them in the gravel. The excess tie will serve as a prosthetic root until the plant can drop real roots and anchor itself to the substrate. To propagate simply cut off the tops of the plants and replant them using the method above.

Q: How do I grow floating plants?  
A: Unlike say elodea which will grow both in the substrate and floating, some plants like hornwort will only grow floating. If you want to grow hornwort as a floating plant then you can stop reading here. There is a way to trick it and make it grow like a stem plant if you want. Here are two methods: Use plant weights. You can buy commercially available ones or DIY them for much cheaper but a little work. I buy a box of 3-inch galvanized nails, blunt the tips with a hammer or an angle grinder and spray paint them either black or dark green to keep them from rusting. Then you can cable tie one or two nails together with a bunch of plant stems, drop them in your tank and viola! Another method I like for this is to take a piece of lighting diffuser, cut it to size, bunch up a dozen or so hornwort stems, thread them through one of the holes in the lighting diffuser and cable tie them together to prevent them from sliding back out through the hole. Repeat until you are satisfied. Then you can sink them with a rock and cover up the exposed egg crate with substrate or other rocks. It is a handsome way to display hornwort and your fish will appreciate having a place to hide on the bottom of the tank.

That should hit all the basics for anyone sourcing plants and fish from my tanks. I’m sure I’ll encounter other questions or think of other useful things to add, but for now I’m going to keep it as concise as possible. Thanks for reading and I hope you enjoy your tanks as much as I enjoy mine!