There are many comments about how expensive it is to have a planted tank. The costs of controlled pressurized CO2, PC lighting, a few styled canisters, and many inches of a high-tech substrate quickly add up to a four digit number, and taking out that second Mortgage seems to be necessary.
Not so. Here my ideas for an inexpensive, yet attractive planted tank.
This includes all of the one-time costs, and some near-one-time-costs, like plants and fish (hopefully).
1.1. Tank ... $100
There are incredible deals for incredibly small tanks, but let's take a nice standard size: 55 gallons. At your LFS or friendly chain store, you should be able to find them for $100 or less if on sale. If they come with a striplight, trade it for something else. Not suitable for growing plants. Keep the glass covers.
1.2. Stand ... $100
If you are a DIY'er, you can build yourself a nice stand for $100. If not, buy one at the store.
1.3. Lights + Canopy ... $70
Inexpensive? Okay, forget about PC lighting.
DIY? Buy an electronic ballast for 4 T8 bulbs ($20), 6 endcaps ($5), a white 10' PVC raingutter ($4), and some wood and hardware ($30). Get 3 48" T8 bulbs, preferably 6500K (hard to find, $5 each). Build the canopy, use raingutters as reflectors, overdrive one of the three bulbs for a total of ~110 Watts.
Not DIY? Buy two narrow shoplights that will fit over the tank. I have seen beautiful ones @WMart with electronic ballasts for $18 ($36). Possibly needs bulbs (4x$5). This will give you between 130 and 160 Watts, mediocre reflectors, and some headache when trying to get into the tank. To resolve that, ask a friend to build you a canopy ($34, for steaks and beer).
1.4. Substrate ... $6
Need high tech substrate with all the nutrients that will last a lifetime and longer? No. I suggest a substrate made out of two layers. Buy a 25 lb bag of "Special Kitty" Cat Piss Absorbent @ WMart, and put some in a jar with water. After lotsa rinsing, let it sit for a few days. If it turns to mush, or raises pH in any way, use it as CPA, and buy some profile ($16). If not, you have an excellent bottom layer for $2. Top off with pea sized gravel (50 lb for $4). About 2" in the front to 3" in the back is sufficient.
1.5. Filtration ... $20
Aquaclear 300. Adjustable output. Sponges. Adjust outflow for less surface agitation.
1.6. Heater ... $18
Via Aqua Titanium 150 Watts. They used to be cheaper, but it looks like
someone realized what a good deal they were. Big temperature dial, separate temperature sensor, no glass, fully electronic.
1.7. Misc Equipment ... $26
Thermometer ($1). Algae scrubber ($3). Hoses for water changes ($15). Miscellaneous things that I can't think of right now ($7).
1.8. Plants ... $40
Do some comparison shopping amongst our kind online vendors. Don't buy bigger sizes for more money. Either they grow, or not. Don't buy more than one of each variety (there are exceptions, like Glosso, which we don't need). Same reason, either they grow, and then you will have a lot, or they don't, and then it doesn't matter if you bought 1 or 10 bunches, apart from the cash that you spent. Buy a nice assortment of fast growing stem plants, and a few easy crypts, swords, whatever you like. Trade with fellow aquarists to get a bigger variety, if desired.
1.9. Fish ... $20
This is up to you, so to suggest a possible scenario... 8 White Clouds ($8), 3 Otos ($4.50), a pair of pearl gouramies ($6). A few ghost shrimp just for fun. Or something totally different.
2. Ongoing maintenance
This includes all the recurring costs, estimates per month.
2.1. Electricity and Water ... $10
Depends on where you live. Let's say $10.
2.2. Fish food ... $2
A box of flakes, some frozen mosquito larvae, and whatever vegetable your fishies like... lasts a long time.
2.3. Test kits ... $1
PH and NO3 test kits for one year ($15).
2.4. Fertilizer ... $4
Some Flourish, Flourish Iron, KNO3, K2SO4, Phosphate
Jobes sticks for substrate fertilization
2.5. CO2 ... $3
DIY... maybe 2 3liter soda bottles, fed into the filter inlet, or a ladder etc.
2.6. Replacement parts ... $10
To cover replacement lamps, sponges, fish...
So to add up:
Startup cost: $400
Monthly maintenance: $30
The real expense is the time that you invest to maintain it. Up to you to consider it labor or hobby...
Did I miss anything?