Recording Audio in a Home Aquarium

[DaJMasta]

Not 100% sure where this thread should go, so it's ending up here. A couple months ago I got a hydrophone to try and record some of the sounds of my tank, partially inspired by the snapping sounds from my copperband eating and partially with the occasional discussion of noise pollution and its effect on our animals. I finally got around to setting it up and testing things out, and earlier today made my first recording during feeding time:


I used an Aquarian Scientific AS-1 hydrophone (with their PA-6 preamp) on a 3d printed bracket that dangled it into the tank a ways away from the glass, then turned everything off for getting as little noise as possible, but I was getting quite a bit of electrical hum, so for this recording I also had a Shure A15HP and 30 dB worth of low band attenuation in software - and the hum is still certainly present. It's neat to be able to pick out some of the sources particularly, but I'd say the recording is largely uneventful - a useful proof of concept.

Of course, mere hours later, I decided I should try a grounding probe in the tank to see if it would help with the hum.... and it removed it entirely. So I've formulated my first rule for recording in an aquarium: use a grounding probe.


It probably won't be required (or at least, as required) if your hydrophone and recorder are battery powered (not ground referenced), but for my setup it makes all the difference (and yes, there is slight measurable AC voltage in the water, though the amount drops when equipment is shut off.) I'll be making a second version of the feeding video with the lower noise floor and better fidelity in the low range, but I plan on trying to get the hydrophone closer to individuals (shrimp, crabs) to try to get more targeted sounds, I want to see what the sound difference is between various pumps/powerheads (and when they are clean vs. dirty), doing some testing to see what actually makes it into the tank from noise outside of it, and since the AS-1 was chosen for its high frequency response, I want to see if I can detect any ultrasonic noises from my livestock.

 

[DaJMasta]

Made another recording the following day with a grounding probe in place.... what a difference. I consider the first attempt obsolete already! I heard copperband chomping and pistol shrimp snapping (both audible from outside the tank), but also mandarin strikes, snail scraping, blenny scraping, and a couple of very quick fish movements. There are a couple of noises I've yet to ID, and a lot of animals/activities seem to be pretty quiet, but I hope to be able to get the mic in close to some of them and hear some more subtle sounds in the future.

 

[Reefer911]

Very interesting!

 

[iReefer12]

This is a really cool experiment. I wonder if all that noise from pumps etc effects the fish health/wellbeing?

Anyone got a guess for the chirping noise? Could be it nessarrius snails communicating that food has arrived? Total blind dart.. I’m assuming it’s a creature in the tank and not electrical?

 

[DaJMasta]

Do you have an example of the chirping noise? I may be able to offer a guess if you've got a timestamp, but there are a few noises I haven't been able to ID.

It's hard to say in terms of health - I haven't seen a lot of evidence of sound based communication between any of them (at least yet), and I don't see different behaviors with the pumps off aside from what you'd get without the strong flow (and with an expectation of food.) It's certainly possible, but while I'd like to check more comprehensively, I can say that external noise (shy of very loud sounds or tapping on the glass or something) are effectively inaudible to anything in the tank because of the pump noise.

I know in larger fish there is evidence of vocalization for communication (and detecting spawning aggregations and such), so I think it would be possible in smaller fish - but the physically smaller size may prefer ultrasound to our normal audio band. In my first glance with a waterfall plot up to 90 kHz open, I at least don't see clear visualizations, but with their likely short duration and probably specific use, I could have a lot more looking to do if I even knew when and how to look for it.

I'd like to check to see if the pumps make a noticeably different noise when clean vs. dirty - these were all pretty dirty and it could be that cleaner pumps would make less (or noticeably different) sound. Could be both a potential avenue to explore in terms of health/noise pollution and a potential diagnostic for when a pump needs to be cleaned. I'd also like to test alternative flow generators (honestly I'm thinking a paddle wheel in a channel) to see if I can get a reasonable volume moving with less noise, and see if anything acts different. I have listened to an air-lift pump in operation in the tank, and while it was much lower water flow, it was still fairly noisy (sounds a bit like percolating coffee.)

As conjecture, I think most fish and inverts don't care about the noise pumps put out, but it could be that there is a few notoriously shy or difficult to keep fish that are sensitive to the noise and our difficulty in keeping them actually lies in the equipment noise rather than the parameters, foods, or tankmates. I don't think my animals show signs of it, but there's a lot of variety in the ocean and away from the waves, it's probably not a super loud place.

 

[strich]

I found your videos at random on YouTube and really enjoyed them! Please do keep doing these sorts of experiments.

Given that fish do possess the ability to determine the location of things in their surroundings, I would guess that the ambient sound of your aquarium does matter. Evidentially not enough for any hobbyists to notice however as you said, some fish could exhibit "shy" behavior if the ambient sound is high enough that they cannot rely on it to help understand and secure their surroundings.

 

[strich]

By the way I'd love to get an update on your experiments in breeding shrimp!

 

[DaJMasta]

Thanks, that's often limited by the spawn I can collect, and while I've got some sexy shrimp larvae coming along (only a few days old), my cleaners/peppermints seem to be spawning less frequently and in less quantity - maybe they're getting older, I can't say for sure. The attempts are continuing, at least, but the success is much less consistent.

 

[Troylee]

That’s pretty cool! My fox face makes all kinds of
Noises it sounds like a baby sucking on a pacifier when he skims the top of the tank for food lol..

 

[topjimmy]

 

[strich]

I just ran into this thisarticle by the way. It would seem coral larvae so use sound to find a healthy reef to settle on!

 

[ISpeakForTheSeas]

I just ran into this thisarticle by the way. It would seem coral larvae so use sound to find a healthy reef to settle on!

The link didn't work for me, but I'm assuming this is the article:

Playing thriving reef sounds on underwater speakers ‘could save damaged corals’

Coral larvae more likely to settle on degraded reefs bathed in marine soundscapes, Caribbean study shows

www.theguardian.com

 

[strich]

That's the one yep.

 

[DaJMasta]

Interesting. Not sure what application it may have in home aquaria or commerical aquaculture, though, since there isn't really a different site they could settle in, but if it gets more of them to settle too, well we need recordings of healthy reefs and we need ways to silence our pumps!

Just as a thought experiment, I've long thought a pump that was basically a water wheel in a channel would be potentially low noise and save for larvae otherwise killed by pumps, but it would require a substantially modified system to operate in (think a closed loop, but mounted to the sides/top of the tank).

I've also heard there has been research into spawning aggregations of larger fish where playing sounds of the fish in the historical aggregation sites gets them to come back to the spot and thus find potential mates better than without, so at least among larger fishes, sound can be an important factor in their lives.

 

[strich]

Indeed I think the science is clear that it matters and it's important in the wild. In a tank I would hypothesise that it may affect some fish stresses.
Something I plan to do in my next tank is try to make sure all mechanical objects have vibration reduction mods on them.