Who Gives A Fish Forums

I've been looking into ways to keep my discus safe, given how expensive they are.

I've got a 405-litre tank with a 500W AquaEl Platinum 500 heater that came with it. I've been thinking about adding a second heater - I know it's beneficial in case one fails, but I'm wondering if it'll actually use less energy overall. I assume having one heater constantly switching on and off to maintain 28C would be less efficient than having two heaters working together.

I've also been looking at the Inkbird temperature controller, which seems like a great idea - it'll notify me if the heater malfunctions and the temperature gets too high or too low. But can heaters really generate enough heat to be too hot for discus if they malfunction?

One issue I have with the Inkbird is that it only has one power plug, so I'd only be able to use it with one heater.

It seems some people suggest setting the heaters to a higher temp than the Inkbird is programmed for. So, if you want the tank at 28c, you'd set the heaters to 30c, but have the Inkbird set to 28c. This has me wondering, what's the reasoning behind this approach?

I've had a heater malfunction in the past, it was a nightmare. The temperature skyrocketed to 92 degrees, I was lucky to catch it in time and replace the heater before I lost all my fish. Having two heaters is definitely a safer option, especially with sensitive fish like discus. I'd recommend checking the temperature daily, or even twice a day, to ensure it's stable. With discus, it's crucial to monitor the temperature closely, as they're extremely sensitive to changes.

I'm a breeder of pricey plecos and also maintain several planted community tanks. I've had two different heaters on separate tanks fail, both getting stuck full on. This isn't the first time I've had heater issues, but it reinforced my preference for using two heaters in most of my tanks. I like having more heating power than needed, so if I'd normally put a 200w heater on a tank, I'll use a pair of 16w heaters instead.

I place my heaters close to the bottom of the tank, horizontally. This setup heats better than vertical placement. Having two heaters provides a backup in case one fails and they also heat more efficiently.

The first tank that had a heater failure was a 40 breeder with a pair of wild discus, some rummynose tetras, and 5 L450 plecos being grown out for breeding. I was working on another tank when I noticed a discus stuck to a filter intake - not a good sign. When I opened the lid, a heat wave hit me. One discus was dead, the other was floating at the surface, and the tetras were mush. The thermometer read 104F, but the L450s were alive, huddled in caves. They even spawned a few weeks later.

I chalked it up to bad luck and just replaced the heater. But then it happened again in another tank. This one held a breeding group of Budrovcan line L236 plecos and 30 fry. The tank temp was 119F. I'd fed the tank the night before, and the next day I had 33 gallons of pleco soup. The heater was a different brand, but fortunately, I had more offspring in a grow tank and could create a new breeding group.

That's when I decided to use a temperature controller on my pleco tanks. I found a basic one made by Azoo. It worked in Celsius, which was okay. I could plug in as many heaters as needed, as long as the total watts were under 1,000. It had one setting - the desired temperature. I like that it had some space between the Fahrenheit equivalent of the Celsius setting, so there was a small range above and below the Fahrenheit number before the unit would turn the heater on or off.

I bought several Azoo units when they were on sale for $12. Now I have 12 of them on my tanks, and they've all worked perfectly for years. Simple and reliable, that's all I need. I set the desired temperature and that's it. No ranges, no cooling vs. heating settings.

As for how much good a controller can do, it can only save a tank from overheating. A heater can only heat, not cool. So, the controller can save a tank from getting too hot but not too cold. But what if the controller fails? That's why I set the temperature on my heaters to 1 degree Fahrenheit higher than the Celsius setting translates to. Normally, I run my tanks between 62-86F, but during the dry season, I need to get the water temp up to the low 90s. I set the heaters to 86F.

It's essential to understand the potential issues with a controller. One problem is that it gets stuck in the on position. My heaters will still turn off at 86F (30C) even if the controller tries to keep them going higher. The one thing the controller can't do is make a broken heater work. If a heater fails to turn on when it should, the controller won't heat the tank.

I'm sure there are units out there that can send text alerts if the tank gets too hot or cold. But I don't use a smartphone, and I don't need that feature. I'm a senior, and I prefer simple, analog solutions.

I've been looking into the Inkbird temperature controller, and one feature that really stands out to me is the ability to programme a desired temperature - in my case, 28c for my discus. What I also like is that you can set an alarm system, so if the temperature drops below 27c or rises above 29c, I'll receive a notification on my phone. This gives me peace of mind, especially when I'm away from home, as I'll be alerted if the heater were to fail, either by not heating enough or by overheating.

I've been using the inkbird 306 series for my tanks, and I can tell you they're great for supporting two heaters - they've got two heating sockets, which is perfect for my setup. I've got the wifi version in one tank and the non-wifi in the other three.

The newer wifi version, which I don't have, is even better - it's got two probes, so you'll get notified if one of them fails. I've been using these inkbirds for years now, and the only issues I've ever had are probe failures - but I've got a system in place to protect against that.

I set my heaters to a slightly higher temperature than the inkbird, and it's to prevent "flickering". When the tank reaches the required temperature, the power gets cut to both heaters, and that's it. If you set it to the same or lower temperature, you might get a situation where a heater turns itself off before the inkbird, and then it's constantly turning on and off every few minutes. So, in effect, I'm not using the heater's thermostat at all - except as a fail-safe, of course.

Using one or two heaters is an option, but I'd say two is the way to go for a bigger tank like yours. Insulating the base, back, and sides with 1-2 inch thick polystyrene foam sheets can really help trap the heat and cut down on power usage.

A coverglass is also a must, not just to stop your discus from jumping out, but to keep the heat in. I'd recommend 4, 5 or 6mm thick glass, rather than the thinner stuff you usually find in pet shops.

Positioning the tank near an inside wall can help keep it from getting chilled by cold air transferring through the outside walls. And try to keep it in a room where people are moving around – it'll help your discus get used to the commotion and prevent them from becoming shy.

I personally like to keep my discus tanks at around 27C, that way if any of them get sick, I can bump it up to 28-30C. When buying a group of discus, try to get them all at the same time and make sure they're all the same size. Adding new fish to an existing group can be tricky, and the newcomers often get bullied.

Opt for fish that are around 3-4 inches in diameter and make sure they're eating well at the shop. Also, keep an eye out for any doing stringy white poop – it's a bad sign in discus. This link has some great info on discus care, including their diet, which should be mainly plant-based.

m.moam.info/scielo.php?script=sci_arttext&pid=S1679-62252008000200016

I've found a local importer who quarantines and deworms his discus for 2 weeks, so I'm confident in the health of the fish. I'll be buying 9 discus at once, all 10cm or bigger - they look amazing. The importer takes great care of his stock, so I'm not too concerned about disease issues.

I've chosen this tank: https://www.aquaristiconline.com.au/pro ... y150-black. It's a large, expensive display tank, so I won't be insulating it - I think it's designed to be efficient as is.

You can still insulate the tank, even if it's a display tank. Just use tape to attach polystyrene foam sheets to the outside of the glass. This will help trap a lot of heat and reduce the power used by your heaters.

I can already imagine the eyesore that would be - polystyrene foam sheets taped to a beautiful display tank in the middle of the room. It's just not an option for me, aesthetics matter. The heaters will have to do the job on their own, insulation is not something I'm willing to consider.