So, You Want to Keep Tadpoles?

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First, time expectations. The whole process takes a variable amount of time, but it is finite and so you can get by with small sizes of the supplies you need. On the flip side, it's a daily commitment and so you can't all go on vacation during this period unless you have someone willing to do manual water changes as well as proper feeding. Of course, you can go ahead and create a multi-tank "Gigaswamp" set up too, if that's more your style. If so, it's likely to maintain itself a lot more robustly. I needed something a bit less complex to start, though we're now looking very closely at the U. Virginia "Two Tank Biofilter" set-up.

We expected about 6-8 weeks before our tadpoles really hit metamorphosis, but some species can take months and green or bullfrog tadpoles are a long-term commitment at 12-14 months. As it happens, the scientists are a bit off; some transformations did finish in 10 weeks, but most were closer to 12-16 weeks and we still had a few un-transformed Pacific Tree Frog (Pseudacris Regilla) tadpoles 9 months later.

If you want to keep any creature properly, of course, it all begins with preparing the home. Except where specifically noted, this stuff is all easy to find at Petsmart, pet stores, et. al.

(1) Dechlorination

Unless you get your water from a non-chlorinated well, dechlorination is the first and most critical step. Reader "SPQR" alerts us that many localities use chloramines, which are more stable and hence more of a problem for aquarists. He points to a very useful review of dechlorinating compounds that should help you.

In addition, sites we've seen strongly suggest using dechlorination solutions and then letting the water sit for a day as extra safety.

Tadpole skins are thin, and are more prone to pass contaminants than fish skins would be. Babies are always more delicate, and even air-breathing adult frogs have limited oxygen absorption capability through their skin, so it's not too surprising to find this issue with young amphibians. They're also sensitive to environmental shocks in general, which can affect development later.

(2) Other tank preparations...

• Wash the tank out, and remove the dust etc. In general, everything that isn't living should be rinsed before it's used.

• Aquatic plants aren't 100% necessary, but they are a good idea. Tadpoles love to rest on them, and find them a useful source of edible algae, but they have to be planted before the tadpoles are introduced. The plants also need to be oxygen producers, not just decorative varieties. A 5-gallon tank should have at least 3 plants, and 4-5 is better. It is often useful to plant them right up against the back, as this makes cleaning easier.
  • Anacharis is a very good choice. Tadpoles seem to really like resting in its leaf structure, which offers so many perches for them but keeps them visible to kids. It can be added just floating, too.
  • Water ferns are also good, and will work in lower light later in the day.
  • Pick other choices as appropriate for the level of sun.
  • At least one floating plant is good, as it offers tads a resting place near the surface where food awaits.

• The plants will need a gravel or sand bottom, if you use them. For a 5-gallon tank, about 2 5-pound bags will do. Finer gravel is better, because it's easier to clean.

• At least one shade-producing ornament is good, as tadpole eyes can be damaged by too much intense light. We bought a small fake rock house. That worked great, but made cleaning a bit tougher. It may be better to just use plants along the back and surface, and avoid really sunny places in the house.

• Because of the light issues, tank lights are not recommended. But the tads do need sun for proper development. We had to move our tank to a part of our house that got at least 3-4 hours per day of sunlight. That may be the low lighting zone in your house, but 3-4 hours of direct sunlight, plus indirect sunlight, is a good number to shoot for.

• A tank thermometer is useful, to make sure sun etc. isn't heating up the water too much. Tadpoles can tolerate a fair bit of variation, but it's good to have a warning if it starts creeping too high.

• A small and very gentle net. The softer and gentler the better, and you'll try not to use it much on the tadpoles, if ever.

• A filter that's very gentle, AND has biological filtration capabilities. This will do a lot to prevent deadly ammonia and nitrite buildups, once the full cycle gets going in about 30 days. That means far fewer water changes for you! The best is Jungle's Dirt Magnet series but some pet shops carry lower quality filters from Lee's. Get a larger filter than you would otherwise buy, especially if you go for the Lee's option. 2-gallon tank? 5-gallon rating. 5-gallon tank? 10-15 gallon rating. Etc.

(3) Air Pump

Air pumps are good to have, but stuff that works for fish doesn't always work for tads. Having air in the tank improves tadpole activity levels and health, but they can't take much current and people have reported problems if the bubbler is too aggressive or bubbles are too big.

• We bought a "Tetra Whisper 10" pump for our tank, and love it. Really quiet, efficient, excellent. We bought a couple different brands for our other tank, decided we didn't like them, and took them back. The Whisper now runs both our tanks, thanks to an inexpensive 2-way adjustable plastic gang valve.

• If the pump is lower than the top of the water, you'll need an aquarium check valve so water never goes into the pump when turned off (siphon effect). Very cheap, very simple, just cut the air hose in two, attach valve to both hoses, done.

• We found a lot of benefit in having an adjustable valve in the hose as well, installed right next to the pump. This lets us control the bubble levels. Some advanced pumps contain built-in adjustable dials, but they tend to be larger pumps with higher air volumes. We didn't want that, as too much is a bad thing.

• If you buy Jungle's Dirt Magnet sponge filter, or a Lee filter, and use the adjustable value so its just percolating along not violently bubbling, you're done.

• If you don't have that Dirt Magnet or can't get that immediately, the scientist sites we saw recommend the floating "Coralife® limewood airstones" that are part of some saltwater aquaria to provide the needed oxygen. We had good results with it. It produces very small bubbles, which are perfect. Then we dial down the airflow valve so it's oxygenating but not disruptive. Sometimes, our frog-children will even rest on the stone!
  • Make sure you screw the Coralife's plastic screw-in attachment into the limewood very well, or most of the air just comes out of the junction. You may need a small 7/16" or 1/2" hex wrench for this.

• We also had some luck in our big emergency tank with an airstone wand attached by suction cups to the side of the other tank. It creates more current than the Coralife, and tadpoles shy away from it more, but it works. Our warnings if you use one are:
  • Attach it higher up on the side of the tank, so it's less disruptive to the water column.
  • Tilt it so the far end is higher than the hose connection end. This gives you less violent bubbles all along the airstone wand, instead of a violent eruption at the base.
  • Absolutely have an adjustable flow valve. You'll need it, and they're really cheap. Dial the valve way down.

(4) Ammonia & Ph

Status at-a-glance
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Tadpoles in this area seem to tolerate a high Ph, but that high Ph has interactions with ammonia content that really lower the threshold for problems. Scientifically, high Ph turns more NH4+ (ammonium) into toxic NH3; below Ph 7.0, almost all of it stays "locked." The critical thing here is the ability to monitor Ph and ammonia levels. The next step is being equipped to do something about them.

Part of this process just takes time, too - different kinds of slow-growing bacteria have to establish themselves. Aerobic bacteria convert ammonia to nitrite (also not good), and then even slower-reproducing bacteria convert nitrite to nitrate. Some sites also suggest that anaerobic bacteria are needed to complete the cycle, turning nitrates into nitrogen gas. The general agreement is that this whole micro-ecosystem takes 30 days or so to spin up, but the tadpoles didn't have 30 days. So we're going to have to ride out first the rising ammonia, then the rising nitrites as ammonia levels, etc., and cross our fingers. Some tadpoles will also be released into the wild, which is less safe for them but removes the possibility of a TPK (total party kill).

Unfortunately, tadpoles can't have conventional water filters that would suck them up or injure them. That means manual partial water changes, which is most of the work of caring for tadpoles.

To avoid the potential for environmental shocks, we introduce any required amounts of Ph control, ammonia control and other aquarium control products to the tank only after diluting them in water. I mention this because sometimes we will make adjustments between water changes. So far, we're also using the following products.

• We bought 2 neat products from Seachem that suction-cup onto the inside of the aquarium, and provide ongoing at-a-glance readouts: "Ph Alert," and "Ammonia Alert." Each cost under $10, and are well worth it.

• Ammonia happens when faster-reproducing "heterotrophic" bacteria grow, and one key starter is when tadpoles excrete into the water. Like other babies, eating, resting, looking cute, and crapping is most of what they do. One way to slow ammonia rise is to stock your tank under its capacity of 4 tadpoles/liter or about 16 per gallon. Our 5 gallon tank is filled to about 3.5-4 gallons, and we have about 40 frog-children which means maximum maintenance. Our other tank had about 250+ tadpoles in 15-20 gallons; it was saved by a combination of the Jungle Dirt Magnet filters described above, and the muck we had necessarily brought in with the second batch of tadpoles, which was biologically active and gave us a big step forward.

• In all cases, we prepared the aquarium water with a couple drops of API's "Ammo-Lock" before the tads went in. We also put 5-6 more drops in the 1.5 or so gallons of "tank change water" before it goes in to the tank, along with any other substances in amounts suitable for the aquarium.

• We bought Tetra's "EasyBalance" liquid, which is designed to stabilize Ph and alkalinity levels and reduce nitrate & phosphate buildups. The small 100 ml bottle is sufficient, and it does seem to slow down forced water changes and improve water quality. An optional extra, but it was our foundation. Since it isn't amine-based, it's OK for tanks with biological filters too.

• We bought a tiny 30 ml (1 oz) bottle of API's "StressZyme" as part of our pre-tadpole tank prep. One of the things that contributes to fish stress from ammonia, nitrate, nitrite, and phosphorous buildup is biologically "dead" water, lacking the beneficial micro-organisms that help remove this stuff in nature. New aquarium fish kills are sometimes traceable to this problem.

StressZyme claims to be one of the products that adds these beneficial, safe micro-organisms. I put it in last, and waited a day so they could multiply before adding the tadpoles. If you have chlorinated water, that's a 2-day wait since the chlorine must be gone for the StressZyme critters to thrive. I'll add here that aquarist and reader "SPQR" is dubious of these products (here's the science behind that view explained), except an expensive product from Marineland named "Biospira," which uses Nitrospira bacteria.

• We bought small 4 oz. bottles of API's Ph Increase and Ph Decrease, so we could adjust Ph levels as needed. Other products are available. This turned out to be not hugely useful, as our naturally high-Ph water has so much buffering capacity that it's very hard to change its Ph. The tadpoles survived anyway.

• Note that because our Ph is in the 8.0+ range, and our water is naturally highly buffered (hence very difficult to change by adding acidics), AND water temperature was often over 70 degrees Fahrenheit, ammonia levels that hit 'alert' status on the Seachem Ammonia Alert (just 1 level above 'safe') were enough to force a water change. High Ph = more dangerous. Higher temperatures = more dangerous. Combination = a lot of extra vigilance required.

(5) Water Changes

Our 2.5 gallon reservoir of chlorine-free changing water is treated with Ph Decrease so it's a bit lower than the tank's reading, plus enough EasyBalance and Ammo-Lock for the whole tank, and a drop or two of StressZyme.

• When changing, we use BiorbUSA.com's Biube manual cleaner pump. Under $10 at Petsmart, has a long enough wand for control, has a grate on the bottom so tadpoles can't get sucked up, and a squeeze to pump water with more control than a siphon.

Method: We put the pump in the middle of the water column, wait until no tadpoles are close, then pump a couple times to get it going. From there, we move it toward the bottom (where the tadpole poo and other ammonia-producing wastes lie), and remove about 1/3 of the water. Then we replace that 1/3 with treated, prepped water that we keep ready to go.

UPDATE: Worked well, but the grate was still big enough that 2 tadpoles rode the siphon (unhurt) during one of the changes. We used cheesecloth and a rubber band to fix this.

(6) Tadpole food:

Overfeeding will also lead to ammonia buildup, and can provide an environment for disease. Anyone who ever owned goldfish knows that - but goldfish are carp; tadpoles aren't as tough, so even more care (and explanation to kids) is needed. This is the hardest part to execute - but we aren't being kind to our little friends if we kill them.

The other thing to remember is that algae = food. In most fish tanks, algae is a problem. With tadpoles, you want to encourage it.

• 2-3 feedings per day are best, in which the top of the water is dusted with a thin film of micron food, or about 1/3 to 1/2 a frozen spinach leaf is chopped up.

• Wait for the food to be gone before feeding again. Some sources recommend waiting until you see the tadpoles swimming around a lot on the bottom looking for food, since some of what they eat isn't easy to see.

• The scientist sites we've found consistently recommend "Sera Micron®" as the best tadpole food. It's not really available in stores near here, and needs to be mail-ordered from HerpSupplies.com or BlackJungle.com. A small 30 ml container will do and it's about $7, plus $7 or so for USPS Priority Mail shipping (2-3 business days).

• Berkeley and Yale have tried adding commonly-available Tetra Min fish food to the Sera Micron all the way through, with the flakes crushed to appropriate fineness. They say this supplement seemed to improve development, more protein and such. We're following that approach, and using a mortar and pestle to grind it before mixing in Sera Micron.

In the meantime...

• While I waited for the Sera Micron to arrive, I also bought a small and cheap pouch of Hikari's Algae Wafers. The sinking algae wafers aren't useful if just dropped in, but we used them with Tetra Min added and ground them in a mortar and pestle until very fine. It was a temporary expedient, but sometimes it's good to have those. The tadpoles loved these much more as they grew.

• Frozen spinach works, but it's a lot of work to do and the payoff is low. Pure spirulina from a health food store is an excellent and very convenient substitute as you wait for the Sera Micron to arrive. We liked it so much we kept mixing it in with the Sera Micron throughout our tadpoles' development. The tadpoles liked it too.

(7) Tadpole Companions, Good and Bad

Having an aquarium filled with tadpoles sometimes leads folks to want to add other creatures. Especially if you have more than just tadpoles in that aquarium.

For instance, you may notice really tiny round moving critters in the water, especially if some of the water came from the pond et. al. where tadpoles were captured. These are most likely water fleas (which are crustaceans not fleas, and aren't dangerous or parasitic) or other zooplankton. They'll be dinner once the tads start changing, but they do multiply rapidly. You can decide you don't care, net them occasionally to keep numbers down, or introduce fish to do that job.

If you do add companions, this needs to be done carefully.

• There is the potential for disease to be introduced. That fish in the pet store isn't always clean.

• A dead companion fish can poison the water and end up killing al your tadpoles.

• Companion fish must be fed different foods, which accelerates dirty water and means more water changes for you.

• Most fish you'd get need water above 70 degrees, which increases toxicity risk for your tadpoles.

In general, you want to avoid this -or get non-aggressive fish that will stay small, are reasonably hardy, and won't compete with your tadpoles. If you feel you must, some guildelines:

• No snails, ever. They can carry parasites that will harm the tadpoles.

• No goldfish/koi, as they're likely to eat or harass tadpoles.

• Mosquitofish appear to be excellent companion & clean-up choices, if you have crustaceans or mosquito larvae. They'll keep a tank ready for tadpoles all year - with an aquarium filter system in use when the tadpoles are gone, of course. Plus, there's a personally satisfying aspect to owning mosquito-eaters.

• Danios and guppies can also be added to our water, as both do well in higher Ph and they never get big enough to be a threat. They demolished the crustaceans in short order, but won't control mosquito larvae.

• Cory catfish... jury is out, didn't try that. I did notice our tadpoles rooting around on the bottom for food a lot. A catfish might be too much competition.

On a less-welcome note, wild-caught tadpoles are likely to include mosquito larvae in the water. They're small and straight, but go into a hyper bending 'dance' when moving. Hence the name "mosquito wrigglers"

• The key thing to remember is that they must come to the surface periodically to breathe.

• After rescuing our tadpoles, I would spend 15 minutes at a time on 'predator patrol,' scanning the top of the water and waiting. Larvae that surfaced were netted and washed down the sink. When the patrol was over, a capful of bleach was poured into the sink drain. [Ah-nuld voice] I am relentless and unforgiving [/Ah-nuld voice]. A few predator patrols on consecutive days, and they're gone. Every now and again I see another and it's predator patrol again. But I don't see many these days.

(8) Metamorphosis Time!

Some species of frog do well in the water. Pacific Tree Frogs, and toads, could die if they can't get partly out of the water now and again to rest and breathe with their growing lungs. The weeds like Anacharis will help, if you let the Anacharis float. In fact, I recommend floating Anacharis even if you use no other plants.

• Once any froglets begin developing front legs, it's probably time to either release them into a viable local pond or swamp, or net them and move them to another specially-prepared tank. Obviously, release is easier.

This other tank should be no more than 1/2 full, and should have a secure top screen, help for the frogs to crawl out onto something dry, plus a decent amount of land you'd be comfortable putting insects on and not having them immediately go into the water.

• Pacific Tree Frogs are a bit like Geckos, in that they can easily climb up the tank sides.
  Once front legs begin to form, you'll need a tank cover so the little froglets can't hop out. A flexible material with some 'give' is better than wire mesh that can bloody noses et. al., but the key is to have the barrier, so compromise if you must. Otherwise, the froglets will crawl out and dehydrate to death before you even wake up in the morning. Your house is designed to be much drier than nature. Good for house maintenance. Bad for frogs.
  
• Your tadpoles will eat much less once their tails begin to shrink. They're changing in many ways, including their digestive systems which are going from plant-based to carnivore. Don't get nervous. Once the tail is mostly gone, however, those frogs will be hungry and they will need insects to eat, ASAP! wingless fruit flies can be found in most pet stores, and make good immediate food.

• Platforms: The smaller turtle docks that attach via suction cups to the side of your tank can serve as a good platform for crawling out, but aren't big enough for feeding. They're useful if you're sing a 25+ gallon wet/dry tank, or plan to let the tiny frogs go either slightly before, or no later than a day after, their transformation.

If you really want to keep Pacific Tree Frogs for any length of time, however, it's a fair bit of work. Seriously consider releases once the front legs form, and before full transformation!

If you are determined to keep frogs, or must keep them for a while, you'll need a full on wet/dry tank to put the tadpoles in once their tails begin shrinking. It has to have biological or under-gravel filtration (we transferred in fully active Jungle Dirt Magnets), and land that spans half of the tank (half going side-side is better than the back half in our experience).

After some abortive designs, we built "Margaritavile" using a 50 gallon acrylic tank loaned by a friend, with twin Jungle Dirt Magnet filters, floating Anacharis, and a "loft" built using PVC piping to create a platform skeleton, plus "egg crate" plastic used for fluorescent light grates that's wrapped in plastic screen as a base for the land. Redwood chips baked for 20 minutes at 300 degrees and allowed to cool form the substrate, and UNDYED moss on top plus some rocks forms the land, with other things added and lots of hiding places. It was a day's worth of work, and in retrospect I'd add a floating "Turtle Log" as well.

We also had to have Rep-Cal's calcium supplement and Herptivite added to the insects to ensure adequate nutrition (use funnel over narrow jar, shake flies in, add small amounts of supplement, shake pour out onto small screen placed over catch for supplement dust, tap screening over tank to introduce flies), and eventually needed to buy significant quantities of mail-order wingless fruit flies, then crickets in bulk (all of which must be dusted if you're keeping frogs for more than a week).

See our April 2008 follow-up for more, written after we had needed to keep many of the frogs for a while, but had managed to let about 180 or so go. It includes frog care tips, cautions, and what to look for when releasing your frogs.

Good luck! Readers with further suggestions, tips, recommendations et. al. can use the comments section to add them....