- Pruning and thinning: I currently trade in excess plants and cuttings from my monthly trimmings to my favorite local fish store (Fountain's Aquarium in La Mesa, CA) for store credit. I only bring in the top quality cuttings and plants, and discard what I do not consider sellable. I usually generate enough credit for fish food and other supplies so that my aquarium is basically self-sufficient (except for whatever I pay more in electrical and water bills).
- Gravel: I originally bought the entire tank and stand, with gravel, from a couple who have given up on fishkeeping, for $80. Being cheap, I kept the gravel which came with the tank. This gravel is too coarse for some plants, especially small foreground plants with delicate roots. The plants would not anchor well or could not make any headway developing a root system. I have recently acquired a quantity of very fine Cambrian gravel (from trading in plant cuttings) and set up a "beach" area at the front of the aquarium, where I am trying to raise small foreground plants.
One problem with the Cambrian gravel was that it contained small bits of shells, which would raise the pH and water hardness (it fizzes when soaked in an acid solution such as vinegar). Since my tap water is already high in pH and hardness, this was not a desirable situation. I neutralized the gravel by alternately soaking the gravel in a solution of diluted Muriatic acid (sold at hardware stores for use in swimming pools) for a few hours, then rinsing when the solution stopped bubbling. (Do not breath the caustic fumes while doing this, and make sure you use gloves and goggles). The shell bits are dissolved and the calcium washed away in the solution. It took me about 3 iterations to completely neutralize the gravel (no more bubbling when new acid is added). The volume of Muriatic acid used was about 3 times the gravel volume.
- Python "No Spill Clean 'N Fill": This is a great tool for water changing. It consists of a long, clear, flexible hose, one end is a gravel vacuuming tube, the other end has a venturi fixture for attaching to a water faucet. To drain aquarium water, you place the vacuum end into the tank and connect the other end to a faucet. Turning on the faucet will create a venturi effect which sucks the water out of your tank. To minimize the wasted water, you should connect the outlet end to a faucet that is located lower than your tank (e.g., an outside/garden faucet). Then you would only need to turn on the water for a couple of seconds, just enough for the venturi effect to draw your aquarium water up the hose, over the tank edge, and down to ground level. Then you turn off the faucet, disconnect the venturi fixture, and place it over a low drain or on your garden plot. Gravity will siphon the rest of the water from your tank. When enough water has been siphoned out, you reconnect the venturi fixture to the faucet, twist a knob to close the outlet, and turn the faucet on. This time the water will run back up the hose to refill your aquarium. Even though I do not do much vacuuming these days (the plants cover 95% of the gravel surface, making vacuuming impossible--also, the mulm is good for the plants anyway) I still can not imagine doing any water changing without this tool. (Note: some people have made their own copy of this Python for less money. Evidently the venturi fixture is also sold at hardware stores, for draining and filling waterbeds.)
- De-chlorinating: I used to use Jungle ACE or Amquel to de-chlorinate my tap water (which has chloramine) at water changes. But having heard from the plant gurus at APD, I decided to stop and just use plain tap water without de-chlorination. It's been working fine for over two years. I believe that you can replace up to 1/5 of the tank water at a time with no de-chlorination. I have noticed that when I went over this ratio, the fish started to show signs of stress (fast swimming, etc.). It could be the chlorine/chloramine concentration or the larger temperature or pH/GH changes that triggered this. Anyway, whenever I do a larger water change, I would add Mardel's MarChlor (sodium thiosulphate, a dechlorinator that does NOT bind ammonia). I leave the free ammonia from the chloramine for the plants to use. (I have not been able to determine if ammonia that is bound by Amquel, for example, is still available to the plants.) The main reason I can do this safely is that because of CO2 injection, I can keep my pH relatively low. At low pH (under 7.5) ammonia exists mostly in the non-toxic form of ammonium (NH4). If you have a high pH and chloramine in your tap water, you MUST use a dechlorinator that also takes care of ammonia. (I have a small tank at work that does not have CO2 injection, with pH of about 8.6, and I have killed fish by doing water changes with sodium thiosulphate only.) By the way, when adding dechlorinator, I always add it directly into the tank, right at the output of the refilling hose. It works fast enough that there is no need for pre-mixing.
- Filtering: One of the nice things about a planted tank is that you don't have to worry much about filtering. The plants do an excellent job of chemical and biological filtering, absorbing the fish waste and converting it to plant matter. All you need to do is to provide some mechanical filtering (I'm using a foam sleeve in my Magnum canister filter) and a water current across the plants (I placed the intake and outlet of the filter at opposite ends of the tank)--although I have seen planted tanks with no filters at all. The necessity for water changes is also reduced (you remove the end product of the fish waste by pruning and removing extra plants). I am not advocating no water changing at all though. Some elements that are put into the tank in the form of fish food may not be used up by the plants and still need to be removed through water changes. Also, the replacement water contains trace elements that may not be present in your plant fertilizers.
I have used various canister filters in the past. In cronological order:
Hagen Fluval 303: My first canister filter was a Fluval 303. It worked quite well and was very quiet. The media baskets made cleaning easy. But it was hard to connect/disconnect, hard to prime (get the flow started), and sometimes had air bubbled trapped inside. Its motor quit after 5 years.
Hagen Fluval 204:I switched to a Fluval 204 (new design, new series). This one was much easier to prime and easier to disconnect with its built-in quick-disconnect (Aqua-Stop) valves. However, I chose a model that was too weak. I discovered after the fact that the Fluval 204 uses the same impeller as the 104, while the 304 and 404 share the same impeller. The difference between the 104 and the 204 was in the body size (media volume) only. Since my primary concerns were with current flow and not biological filtering, I should have gone with the 304, not the 204. One other inconvenience was that plant matter kept collecting at the Aqua-Stop, clogging up the intake. Whenever that happened, the water inside the filter became foul and some fish would die. I think that this could have been prevented if I had used a prefilter sleeve over the intake. I got a prefilter, but before I could install it, the impeller seized up, overheated and the impeller housing melted (after only about 1 year of use)! My 204's impeller had a tendency to stop, or not started sometimes, and had to be banged on to get going. I don't know if this is a problem with my unit, or it was a poor design by Hagen. I didn't care much for their new impeller well design with the ceramic rod in the middle anyway. I broke one on accident while trying to take it out for cleaning.
Marineland Magnum 350:My experience with the Fluval 204 turned me off the Fluval line (I used to be a Fluval proponent). I went to the fish store, used up the rest of my plant trade-in credit and got a Magnum 350 (it was cheap). The Magnum 350 has terrific flow and the self-priming feature is great. But it is somewhat noisy (the Fluvals were totally quiet). I think that I will eventually switch to an Eheim 2217 canister once I have accumulated enough trade-in credit again.
- Surface Skimming: There usually is a thin milky layer on the water surface. This layer is probably caused by excess protein and reduces the amount of light reaching the plants below. It can be eliminated by three ways:
- Agitate the surface to break it up by directing the output flow of the water filter at the surface, then the protein will mix with the water below and get filtered out. This method will lead to greater CO2 loss at the surface, however.
- For a long time, I used the second method: skim it off the surface, in this case with an Eheim Surface Extractor as the filter intake. It did the job. However, it is not ideal for a planted tank, because it also sucks in floating bits of leaves, which then will need to be manually removed every few days. It also makes some vibrating noise occasionally.
- I recently learned from the newsgroups (from Ole Larsen, to be specific) that Black Mollies will eliminate surface scum. I immediately bought 4 Black Mollies and added them to my tank to try them out. It worked! I shut off the Eheim Surface Extractor and the scum has not reappeared. The Mollies constantly dart about just under the surface, and skimming off the scum layer. I wonder how much of a food source this scum contributes to the Mollies' intake, but I have to say that this is the best method of removing surface scum that I have found.
- Fluorescent lights: It's best to buy the larger T12 type
(1.5" diameter) endcaps. Then you can mix bulbs and use any type you later choose. If
you use smaller diameter bulbs (as I do now), just wrap some tape (electrical or duct
tape) around the ends to bring them to the proper diameter and make a good seal. Same with
holding clips.
Appropriate light intensity level: When I first started the tank, I had just 80W of fluorescent light for almost a year. This was just barely adequate (even though I used PennPlax Ultra Tri-Lux, the brightest
bulb in its class). I could not grow some of the more demanding plants. Also,
when I tried the controversial "thunderstorm" period mentioned on the net (1 or 2
hours of darkness at mid-day, supposedly to discourage algae growth), most of my plants
(except the Cryptocoryne wendtii and the Anubias nana) performed poorly and I had
an outbreak of brown (gravel) algae. When I upgraded to 120W, the plants perked
up and regained their vigorous growth. My light level is now close to the 2 Watts/gallon
level recommended for aquariums of this size. From information gathered on successful planted tanks, I have concluded that the rule-of-thumb for lighting is a ratio that varies between 1 and 4 Watt/gallon, starting with over 3 W/gal for 10 gallon and smaller tanks and going down to around 1-2 W/gal for 200 gallon and larger tanks. Another solution was proposed by Erik Olson, who collected and posted light level data from newsgroup posters and Amano tanks, and hypothesized a linear relationship between required light level and tank surface area.
Bulb selection: With a relatively low 1.6 watt-per-gallon ratio, I need to use the more efficient bulbs, such as PennPlax Ultra Tri-Lux and Phillips Advantage. If I had 160W (2.1 W/gal), I probably could go to cheaper bulbs such as the GE Daylight Ultra. It's a tradeoff of bulb price vs. the cost of electricity. I think they are about the same in my case. It is also a good idea to have a mix of different bulbs, to cover as much of the light spectrum as possible, since there is not yet any definitive conclusion on what light frequencies are best for aquatic plants. Conventional wisdom says red and blue, while Amano and Diana Walstad lean towards green (from their books). Diana Walstad reported in her new book (Ecology of the Planted Aquarium) that a combination of cool whites and VitaLites gave the best growth for Elodea. I usually try to include at least one Penn-Plax Ultra Tri-Lux in the mix, however. The Ultra Tri-Lux is my favorite bulb, pure white, very brilliant and makes the plants and fish look much nicer (see my Fluorescent Light Comparison page).
For my picks on the best bulbs and combinations, see my Questions and Answers page. My current bulb mix is given on the Technical page.
-
How to find the appropriate lighting duration:
This is
something I just observed: With adequate light levels, I think you can tell how long the
plants require the lights to be on. The Hygrophila polysperma, which normally have leaves
spread horizontally, folds up their leaves after about 11 hours of light. I think this
is an indication that they have obtained enough energy for the day. This is the only type
of plants in my aquarium that exhibits this behavior though. I do not know the duration
required for the other plants. I would be interested in hearing feedback from other
people regarding this observation.
Electricity and water:Pure water does not conduct electricity. However, water with dissolved minerals, as in our aquarium, becomes an electrical conducting medium. All electrical aquarium equipment should be plugged into a GFI (Ground Fault Interrupt) outlet (I believe in Europe this is known as ELCB--Earth Leakage Circuit Breaker). You can buy a GFI outlet from a home improvement store (e.g., Home Depot) for a few dollars, and replace the outlet which you plug all your aquarium equipment into with it. A GFI outlet compares the electrical current between the hot and return wires, and shuts off the power if they are not the same (i.e., some current leaks off to some other path). It works instantaneously and on very small amounts of current, protecting you from getting shocked if electricity from your heater, filter, pump or lights ever comes into contact with your tank water.
Laterite:My plants were doing well for the first 6 months, growing and multiplying briskly. Then the swords stopped growing. Following advice from rec.aquaria, I decided
to try adding laterite balls near the roots of plants which require
rich substrates, such as Amazon Swords and Cryptocorynes. The laterite is said to work best
with undergravel heating cables (they supposedly help bring nutrients to the laterite, which
provides a site for some metals to chelate, as well as providing its own rich
source of iron). I don't have undergravel heating, but used the laterite anyway. The laterite did improve the growth of the sword plants, producing larger and healthier leaves. However, the accelerated growth stopped after about a year, probably signaling the exhaustion of the nutrients in the laterite. I believe that a cheaper alternative would be to use a macronutrient root supplement, such as the Jobe Plant Food Spikes for Lush Ferns and Palms (16-2-6), pushed into the root zones, and a liquid iron and trace element supplement. The advantage with the laterite balls is that you only have to add once a year. But it makes gravel vacuuming messier--some red laterite comes up every time I vacuum.
- Peat moss plates: The peat moss plates allowed new plants to anchor firmly and get establish very quickly. They also help lower the water pH and hardness. However, eventually they become more of a nuisance. Every time a plant needs to be pulled up (for pruning or rearranging), some of the peat comes up also and dirty up the water and gravel surface. If I were to do it over again, I would use loose peat instead of the peat plates, and only for the water conditioning effects.
- Fertilizers: There is no such thing as a perfect fertilizer for everyone, because everyone has slightly different water condition, fish load, plant load, etc.
In the aquarium trade, "plant food," "fertilizer," "water conditioner," etc. have at times been used synonymously. You have to read more than just the label to know what it is. The term "fertilizer" is not used by some manufacturers (e.g. Seachem), to avoid having to comply with fertilizer labeling laws. They can do this because most aquarium fertilizers do not contain phosphorus and nitrogen, two major components of "fertilizers." These two elements are expected to be supplied via the fish food, although if your plant load is really heavy, you may have to supply them directly also. (Nitrogen, potassium plus a small amount of phosphorus can be added to the substrate through the use of Jobe's Plant Food Spikes for Lush Ferns and Palms (16-2-6). This was first suggested by Karen Randall on the APD.)
Most aquarium fertilizers contain trace elements (micronutrients) and some macronutrients (e.g., potassium, and sometimes nitrogen and phosphorus in the forms of nitrate and phosphate). Some only delivers a particular element (such as Flourish Iron). Some elements can last a longer time in the aquarium, and some only a short time before they oxidizes and/or turn into a form that is not available to plants. That's why some fertilizing regiments require you to add a product weekly (or monthly) and another product daily (or every few days).
I would suggest going with one line of product, and not mixing them, until you have become more familiar with what each product does. You may have to try several products before settling on the one you like. I have used Tetra Flora Pride and Ferro Vit in the past, and was not impressed with them. I have also tried tablets made by Delaware Aquatics for a few months when the tank was young, and experienced an explosion of hair algae (Delaware Aquatics tablets have tested positive for phosphate). I found Seachem Flourish to be great, able to bring my Amazon swords back to health several times.
Curiosity started me experimenting with making my own fertilizer from the PMDD formula. This fertilizer was added daily (one squirt) into the water, and provides trace elements, nitrate, and potassium. The PMDD method requires a lot of observation and adjustment of the formula. I did not have the patience for that, so I just stuck with the basic formula. It did not work too well after about a year; some nutrient deficiencies began to show up.
Having seen the effect of each different fertilizers on my plants, I now use a flexible regime of:
- Weekly addition of Seachem Flourish, injected into the gravel with the supplied injector.
- Daily (or every two days) drops of Seachem Flourish Iron and a squirt of the PMDD solution in the morning.
- Monthly addition of either two Jobe's Plant Food Spikes for Lush Ferns and Palms or two Delaware Aquatic tablets, pushed into the gravel near the large swords. Now that my tank is filled with plants, the addition of phosphate does not lead to hair algae anymore. And the additional nitrate and potassium are welcomed by the heavy feeders such as the Amazon swords.
My fertilizing regime seems complicated, but that's only because I still have a lot of the supplies of various fertilizers left to use (e.g., the Delaware Aquatic tablets and the PMDD ingredients). I believe that I can leave those out and will still get good results with just the Flourish/Flourish Iron and Jobe's Spikes.
Latest news: I experimented with the new Seachem Flourite gravel. Instead of using a pure Flourite substrate as recommended, I bought a bag and mixed it into the top level of my existing gravel. I am happy to report that I haven't had to add any other fertilizer for a few months now and my plants are doing just fine! It seems that the iron-rich Flourite combined with regular addition of fish food and water changes provide enough nutrients for the plants for a while.
- CO2 injection: Normal CO2 level in water is very low compared to air, and is not enough to support vigorous growth for some plants. Although you can maintain plants without CO2 supplement, it means that you may not be able to grow some plants, and your plants may not be very strong. You MIGHT also have some algae to deal with, since your plants might not be able to outcompete the algae for nutrients.
To encourage stronger plant growth, I use CO2 injection. In the beginning, I used the low-cost CO2 injection method. At first, I placed the free end of the CO2 hose such that the bubbles hit the canister-filter intake, and are sucked in and mixed inside the canister. This sometimes generated CO2 pockets inside the Fluval filter which resulted in pinging noises and reduced power (the Eheim has been noted as being able to handle this better). Then I introduced an air stone to break the CO2 into smaller bubbles before feeding them into the filter intake (to facilitate absorption before reaching the filter impeller) and this reduced the frequency of the problem. I later switched to another reactor design (the CO2 bell). See my DIY Yeast-Generated CO2 page. The plants responded to the additional CO2 wonderfully, producing steady streams of oxygen from the leaves when the lights are on, indicating that photosynthesis has saturated the water with O2. They also look more vibrant and producing new growth much faster.
However, after 4 years of DIY CO2, I finally got tired of having to remix the solution every month, so in July of 1998 I switched to a pressurized CO2 system. See my Pressurized CO2 System page for description of how I set one up for about $100. A 2.5-lb CO2 cylinder lasts about a year for me.
Note: Some people have expressed concerns about suffocating their fish by injecting CO2. This does not happen. Unlike in air, injecting CO2 into the water does not displace O2 (their concentrations in water are roughly independent). In fact, with added CO2, O2 level should increase during the day due to photosynthesis. At night, with more plants respiring, there is a theoretical possibility that they use up more O2 and leave too little for the fish. However, this is very unlikely unless your plants are so dense that the fish can't move. One thing that you should pay attention to is the pH drop associated with CO2 injection (CO2 + water = carbonic acid). How much your pH drops depends on the KH (alkalinity) of your water. The lower the KH, the more the pH drops for the same amount of injected CO2. You should obtain pH and KH test kits. From the values for pH and KH, you can determine if the CO2 concentration in your tank is in the optimal range. If your KH is so low that for the optimal CO2 concentration the pH has to drop too low to be comfortable for your fish (your fish can die from acidosis if pH is too low), you can raise KH by adding baking soda to the aquarium. This will also raise the pH, given the same amount of injected CO2.
- Plant-eating fishes: My Amazon Swords sometime have the horseshoe-shaped byte marks typically associated with the Clown Loaches. They are not as prevalent whenever I feed the loaches more heavily.
- Algae control: My strategy for algae control involves attacking the problem on many fronts:
- Using the PMDD fertilizer formula, which presents no phosphate input to the aquarium water.
- Use substrate fertilizer to feed the roots of the plants directly and keeping the nutrients out of the water column (some phosphate is present in substrate fertilizers).
- Use a mixed crew of algae eaters. Each species of algae eater usually specialize on one type of algae. The numbers in the list below indicates how many of each species I currently have in my 75-gallon tank:
- Otocinclus affinis (8): Excellent consumer of the regular, green fuzzy type of algae that grow on leaves. However, otocinclus's are very small, so many will be needed to do the job. They usually stay in the shade during the day, and come out when the lights are dimmed.
- Siamese Algae Eaters (Crossocheilus siamensis) (6): Consumes beard and brush algaes. Also a very fun fish to watch, moving from plant to plant and constantly nibbling at the surface of the leaves. Unlike the rest of the algae-control crew, these fish do not have the rasping mouth that is made for scraping low-growing algae. They have the normal mouth built for nibbling at longer strands of algae--and that also contributes to their livelier behavior.
- Dwarf Pleco (Peckoltia vittata) (2): A very effective driftwood cleaner. Even more reclusive than the Otocinclus, they tend to hide during the day. They are more active in the evening when the lights are dimmed.
- Farlowella (2): These guys are known for cleaning the aquarium glass. Mine usually hang on the front pane of the tank most of the day. However, my aquarium is acrylic and I have green spot algae on the acrylic, which is very hard to rub off. The farlowella are not succeeding in keeping the glass clean all by themselves, and I have to give them a hand by scrubbing the front and sides manually whenever I change the aquarium water. I have heard that green spot algae on the glass would need to be manually removed in any case, for no algae eater can handle them, but at least the Farlowellas keep the glass clear of other types of algae.
- Malaysian Trumpet Snails (quite a few): These guys burrow in the gravel in the day and come out at night. Just about the only way to see them in action is to shine a flash light into the aquarium in the middle of the night. Then they can be seen moving on the leaves. They are the only snails in my aquarium that have survived against the five Clown Loaches.
- Beard algae: I had a bad case of beard algae a few months after the tank was
started. Following advice from newsgroup posters, I ordered Siamese Algae Eaters (SAEs) from the Albany Aquarium (in Albany, CA). The SAEs
that arrived were really young (~2cm), but at the same time they arrived, the
beard algae started dying en masse, collecting at the filter intake. I don't
believe the SAEs were responsible, since it happened too quickly after they
arrived, and they seemed too small to eat the tough strands of algae (I did
notice them nibbling at the tips of the algae strands, but not vigorously).
Unless cutting off the growing tips kills the beard algae, I think the beard algae probably fed on something which resulted from the tank cycling process and died out when that particular nutrient was
depleted. The beard algae episode lasted about 5 to 6 weeks. After that, there were a few short strands of beard algae left on some sword plant leaves, but they weren't a problem. They
disappeared completely after the introduction of CO2.
- Red fuzz algae: After the beard algae disappeared, a red,
short, fuzzy algae covered my large piece of driftwood (and nothing else).
Neither the Siamese Algae Eaters nor the Otocinclus could handle it. Again, from
net advice, I bought what I thought was a Peckoltia pulcher (Clown Pleco), and it did a
wonderful job, cleaning up the entire piece of driftwood in 3 nights and kept it clean thereafter.
However, it didn't seem to do anything with the other types of algae, and hid under
the driftwood all day. I gave it away after a few weeks, and the red fuzz algae started
to come back. I have since re-identified it as a Peckoltia vittata. The fish store refers
to it as both Dwarf Pleco and Clown Pleco, synonymously. I later got an Ancistrus temmincky
(Bristle-nose Pleco)--a little larger, uglier, and less interesting--to clean the
driftwood. It didn't do as good a job and made holes on my Amazon sword leaves as it scrapes
the algae. I gave it away again and bought another Peckoltia vittata.
- Malachite Green: I have found that malachite green is very bad for algae eaters. I have killed young Siamese Algae Eaters and Farlowellas after using medication containing Malachite Green to treat other fish in the tank. I do not know if it is harmful to all sensitive fish, or if it has a way of concentrating in the algae and thus harms algae eaters more.
- Breeding Angelfish: Two of my angels paired up and laid eggs on an Amazon
Sword leaf. They took turn guarding the eggs as they mature--a very nice
sight to see. At first I attempted to leave
the babies in the community tanks for the parents to raise. It did not work well. The
parents did defend their territory and tried to protect the babies. However, the Black
Skirt Tetras were just too determined. They conducted sneak attacks and eventually ate all
the babies. When the angels bred again, I removed the babies as soon as they were
free swimming, and raised them in a separate 10-gallon tank. Baby brine shrimps were hatched
to feed the baby angels. From an initial batch of 50 babies, 12 grew up to adolescent
stage. I kept two and gave the rest to the aquarium store where I trade in my plants cuttings.
- Photographing: All pictures at this site have been photographed without flash, using just the aquarium's lighting. The pictures were taken at night, with the room lights turned off to eliminate reflections. I use two different cameras, a Canon A-1 with 200 ASA print film (usually Fuji), and a Sony Mavica MVC-FD7 digital camera. The Canon is usually used for wide-area shots (due to the higher resolution of film), mounted on a tripod and with shutter speed set at 1/60 sec. to keep motion blur to a minimum while allowing a workable f-stop. The digital camera is usually hand-held and used for closeups of individual fish (the "field" mode is used--equivalent to 1/60 sec. shutter speed). Although both cameras could be used for the closeups, I chose the digital camera because it has autofocus and is more convenient (no need for developing and scanning the pictures later). Regardless of the route, all images are color corrected and contrast adjusted using Paint Shop Pro before posting to the web.
- Catching fast fish: Catching a fast fish in an aquarium full of plants (without tearing up the plants) can be quite a chore. I unsuccessfully tried to catch my Rainbow shark for a long time. I even offered to pay $20 to my brother-in-law, a self-proclaimed expert fish catcher, and he did not succeed. I posed the question to the Aquatic Plants Digest group, and got several different suggestions. I tried one suggestion and built a trap out of a 2-litter bottle with its neck cut off and inverted, leaving food tablets inside the bottle at night as bait. But in the morning, the tablet would be gone and no one was inside. Finally, what worked was a combination of patience and deception. Every evening I would put a food tablet inside a net and leave the net at the bottom of the tank, with the long handle sticking up. Some fish would eventually ventured in and got the food, usually when I was not around. This went on for three or four nights. Eventually the fish got comfortable with the net. One evening, I was preparing to leave another tablet as usual, but just as soon as I dipped the net in, the Rainbow Shark came out to investigate, right in front of the net. So with one swift motion, I scooped him out. I felt somewhat bad having betrayed his trust. But hey, all's fair in aquarium keeping.