Pond Boss Forums INTRO Questions & Observations Starting an article for submission to Pond Boss

And ask the following day if I enjoyed them.

What brand did you get? Got a link?

I have the control system, just need some inexpensive elements. Some of the industrial ones are pretty expensive. I have AC Current Transducers to determine if a heating element craps out, so I can use the cheap ones.

Thanks

Been browsing around looking at aquarium dechlorination stuff. I see that Sodium Thiosulfate is the primary in a few of these now. That's cool!

The two chemical dechlorinators one would want to look for if you planned on having fish-n-chips would be sodium thiosulfate, and even a better one, Sodium Ascorbate (Vitamin C) PH Neutral version.

Could be many reasons that a product is labeled "not safe to use with fish intended for human consumption". A big one could be that their manufacturing process can not meet the stringent requirements that are required for a product that could be potentially incorporated onto ones dinner plate. Also could be that they don't want to deal with the regulations. Who knows for sure!

Just thought I would kick that out for thought.

This is pretty cool!

Aquarium Controller

Not too expensive for what it is either.

More often that not the reason it would not be FDA approved is because the company had no interest in doing a clinical trial to determine the meat withdraw time, or how long any of the chemical derivatives would persist in the meat. The cost of this kind of research is very high.

In vet medicine, just about every medication or treatment that is approved for use in food animals has a meat or milk withdraw time, where the animal can not be harvested until that period has passed.

Just like I said in a previous post it all comes down to money. Of course if the product is primarily used in the pet trade there isn't a good reason to even bother spending the money.

Thanks Cecil. Many options out there in the aquarium world.

Been reading aquarium sites about heater malfunctions. Many have happened.

One guy had a 1000 watt heater. He went to bed and everything was fine. Woke up the next morning, and his tank was 120 degrees. Needless to say, the fish were all dead. Controller fried and got stuck on.

I have three built in methods of dealing with this scenario. Wont bore you with the details.

A number of people recommend to use multiple smaller heaters, so if one croaks, the others are there for backup.

Another recommendation I have seen several times is to replace your heaters every 2-3 years. As they get older, they are more prone to malfunction. (all about cycle life)

I'm looking at one of my 10 amp solid state relays for firing the heating element and wondering how they crammed that into one of those aquarium controllers?

The main advantages of using industrial elements are, they will last a bunch longer, and in 15 years, I can easily get a drop in replacement. Bad thing is that a reasonably priced 1000 watt element could set ya back 300-400 bucks.

I had one stick, and when I came back after being out of town for 2 days the house stunk pretty bad........

I had a baby softshell turtle in the tank, and that's the only thing that stayed alive.

It would be interesting to see the circuitry in these aquarium controllers.

Heaters are resistive loads and generally are not prone to "frying outputs on" (welding contacts) as inductive loads with high inrush current are. (motors, solenoids...) It could happen tho if the contacting mechanism is of poor quality.

I have seen many, many times where an inductive load has fried the output on. With proper surge suppression of the inrush current, this is greatly reduced or eliminated.

If one were going to build a heater control unit. I would think an Opto-Coupler would be employed, at the very least. A solid state relay is an Opto-Coupler, and generally last forever, if properly applied. Opto-Couplers have no moving parts.

Another method is to use a mechanical relay. Same principle as a light switch or circuit breaker with a mechanical contacting mechanism. These are limited to X-amount of cycles tho. A decent mechanical relay may have a usable life of about 100,000 cycles with a resistive load. With an inductive load, that is seriously reduced.

Another resistive load you are all familiar with are lights. I have never had a light switch "fry on", but then again, never sat there and flipped it on-off a hundred thousand times. Had a couple physically break in my lifetime. Not saying you should use a light switch for turning on a heater, because it could possibly melt and cause a fire hazard.

One place I get called in from time to time to chase gremlins, is a plastic extrusion company. One particular machine has a 12 zone barrel. The heating zones range from 7,000 watts to 16,000 watts. Yeah, this thing sucks some juice! Anyway, this uses Opto-Couplers (Solid State Relays) to fire the elements, and the control method is a PID Loop. (Proportional-Integral-Derivative) (If interested look it up. Wikipedia has a decent explanation) The machine is about 12 years old now, runs 21/7 (couple hours a day for maintenance) The PID fires the elements thru the SSR's on average of every 5 seconds, and never once have they ever replaced a SSR! Never once have they replaced an output firing the SSR! Pretty good odds I would say! They have a couple more lines there that use mechanical relays and they are constantly being replaced due to failure.

BTW, the only gremlin I ever found in all my dealings, had a name tag sewn on their uniform

Just thinking out loud here!

Any updates?

I haven't had any problems yet but I do check several parameters on a regular basis including temp.

Like I said one of the high school's bought one of AES's "industrial quality" heaters and they even had to hire someone to wire the heater to the controller. It's worthless now. $300.00 + for nothing.

Which model did they get?

It would be proper protocol to have a licensed electrician hook it up. An electricians job ends after all the wires are landed in the proper place, and are of appropriate size. Don't expect an electrician to deal on the technical control side of things. Some do, some don't.

AES carries one manufacturers brand that has a pretty neat unit out now. AES doesn't have them on their web site.

One of the units that AES sells has an over temperature protection device. This is a one shot device meaning it will blow, similar to a fuse, and needs to be replaced. It was the model that Greg Grimes posted earlier in this thread.

I looked at that one (1000 watt model) because it is reasonably priced.
This would be the only offering from AES that I would be interested in.


It's on my list of possibilities. I'll just bypass the over temperature device, should I go that rout. I have other methods of dealing with over temp. that don't require replacing parts.

One thing I am finding out on some of the aquarium heaters is that the actual elements are made from Aluminum mesh. From what I have found out, Aluminum mesh elements can not handle too many on-off cycles before they are toast. A PID Loop would probably kill one in short order. I'll try one tho. Whats the difference in melting temperature between Aluminum mesh and Tungsten?

If you did not know. The elements are inside the sheath material. In the pic. you see the long tube. That is the external sheath. They make them from various materials like Stainless Steel, Monel, Titanium... The heating elements are inside the sheath. You can get heaters that look like a bunch of skinny rods all formed up (bent) in many patterns. These also have an element encased in a sheath. Big problem with these is that if there is any organic build up, the build up will insulate it from the water, requiring more power to do the job. Not intended at all for this type of service. Clean Fluids!!!

Still have to clean any type of heater in an RAS on a regular basis. I'll know when it's time by monitoring current and temperature.

Still trying to figure out the best place for the heaters. It will be after the primary filter, but thinking before the biofilter. That way I can probably keep the biofilter a bit warmer than the tank. Defiantly don't want it in the tank.

Biggest problem on the consumer side of things, is there are really no technical specifications one can reference. About all they have are buzz words and marketing glitz!

I just got a Chromalox catalog, but haven't had the time to open it up. Another brand I am looking at is Watlow. These companies have been in the biz for many, many years. Omega Engineering is another one, but they are a bit ridiculous on price.

Cheap Aquarium heaters have been the cause of house fires and a few electrocutions. One well known company recalled everything they ever manufactured on one model of heater they produced. Think it was like 1.2 million units. Kinda scary!

Bruce - How well are the fish eating pellets? Update?

It would be a monster fish to eat a pallet, or add the 's on for multiple pallets.

Just kidding!

Phil,

I don't know what model they got but I can take a look next time I'm over there.

My thinking is if the aquarium heater is not over sized, as in just sufficient, how could it overheat several hundred gallons if was stuck on? Maybe in an aquarium, but in a system with several hundred gallons or more I think it would be tough to really heat up the water to lethal range. Seems to me the most likely thing for it to do is to stop functioning, which is much less life threatening.

Phil,

Maybe Bruce has big enough fish to eat pallets now!

"Pallets" you guys are funny!!
You know he really meant pullets...

How disappointing if they are only big enough to eat pullets. I thought Dr. Frankenstein Condello was past that point!

--- --- ----

You are correct in thinking that Cecil.

In a perfect scenario, and there was absolutely no heat loss. You have 300 gallons of water and the temp is 80F. Let's say that 100F is lethal. With a 1000 watt(100% efficient) heater, your fish would be dead just on the inside of 15 hours. 30 hours with a 500 watt heater and 60 hours with a 250 watt heater.

The planets would have to pretty much line up for this to happen tho.

So if I wanted to make a cage out of PVC, and this stuff..



(which is listed as non-flammable by the way)

...how would I heat the inside of the cage, in the presence of an oxygen tank, without risking explosion?

Oxygen is a what? In the presence of what? Non flammable materials are a what? What's in them?

Don't confuse all these what's with watts

I must be a little slow today, but I'm not sure what you're getting at.

Bruce - by cage do you mean tank? To me a cage has a mesh as walls. Would the foam be on the inside or outside of the tank?