ok heres my problem

L

larrycivic

Premium Member
i started this new clam tank....well it is a zero edge tank, that i am having a tuff time heating. it is only about 35 total gallons, but i guess the water going over the sides of the tank are cooling the tank to quick....i have two heaters in the sump and i can not get the temp above 74 degrees....aaarrggg :evil:
 
Larry do you have a picture of this setup?

One would think the lights would heat up the tank.
What is the gallon size of the sump and pump?

Is it possible to do a smaller return pump so the heaters have more time to heat the water?

I have never used them but have heard of an inline heater called "fire plug" that looked interesting.
 
What temperature are the heaters on? Are they working? Simple questions, I know, but thought I'd ask :wink:
 
the heaters are working....the lights come on and everything...one is a 50 watt, and the other came off of my old 100 gallon tank.

the sump is about 10 gallons, and i am using a mag 5 as a return...and i have throttled the flow on the return way back.
 
With the larger surface area you will most likely have to step up the heating ability, or place and monitor the heater from the display.
 
i have throttled the mag 5 back to about 20% flow, and the temp has risen a degree... i currently do not have a light on the set up...but still i have to fix this problem b/c of night time temps.
 
The obvious solution would be to get 1-2 more smallish (100 watt) heaters, set 'em all for the same temperature and let 'em work together to bring the temp up. Try to spread 'em around the sump as much as possible so they're not all glommed together. Although I can understand the reluctance to having that many heaters for such a relatively small volume of water...

Another option to consider might be an in-line heater plumbed into the return line, so that warm water is sent straight into the display...
 
Oh yeah, something else I just thought of... With the problems of keeping the water warm, what's your evaporation rate looking like? That could also become a problem once the tank's running too... Better to think of it now than after there are clams in there... :)
 
It sounds like you have a defective heater. For 35g, you need 100w of heat. 150w tops. Plus, once you have a light shining down to cook the water, it will be far easier to maintain temperature.

What is the ambient temperature of the room?
 
the temp in the room is 72....i think it is b/c the water coming over the sides of the tank cools fast....and there is a fast turn over rate in the sump....so the heater can not get all the water warm....i believe that when the water gets up to operating temp it should do fine until there is a long power outage.
 
ok my big heater has gotten the temp up to 78.3....my main tank right now is at 80.1 with no heater on it.


still trying to figure stuff out.... :)
 
Turnover rate has nothing to do with the heater. It heats the water to its set point, then shuts off.

The room being 72F and the water on the walls of the tank are cooling significantly. Finally a tank that doesn't need a chiller. :lol:

It should be interesting to see where you are when the room is hot during the summer.
 
ok i am thinking about this wrong...the turn over rate is fast so the temp can not get to the set point...plus the temp is being coolrd by going over the walls...wouldn't this effect the temp....did i just confuse myself?
 
Okay, let me see if I can give you a visual.

You are stirring a pot of water and heating it to boiling. If you just leave it alone, it will boil. If you stir it, it will boil. If you stir it hard, it will boil. It may take a bit more time because you are mixing in air during the stirring, but eventually it will boil, right?

Just because the water is moving at 10x per hour doesn't mean the heater can't heat it properly. It may take longer to get to that point, but eventually it will reach it. I do think the room's temperature may have a bearing because the four outer walls and the troughs are cooler than the inside of the tank and sump, but I don't think it would be so bad that the heaters can't keep up.

Did you actually touch the heaters to see if they both feel warm?

Also, those guys that have SPS tanks with 30x turnover or greater still have to heat those tanks, and the heaters work in there. Flow really doesn't have much of a bearing imho.
 
I think the problem is coming from the water being cooled faster than the heaters can heat it. Marc's analogy is correct except if you keep taking water out of the pot, cool it and replace it, it may never boil. That is the effect the zero edge is having. The cooling rate is faster than the heating rate. Bigger heaters or more heaters look like they are in your future.
 
Why don't you try cutting a piece of plexiglas to fit the top of your sump? It would cut down on the evaporation and it seems like it would thus help hold in the heat.
 
I also think that the water falling around the outside of a tank like that causes faster evaporation, which is leads to addtional cooling.
 
I agree with the extra cooling being caused by the extra cooling provided by the water going over the wall. Since the more surface area that you can expose to a temperature difference, the faster the temperature will change and seek to reach equilibrium. With the extra surface area provided by the larger 'overflow', I would assume that it would change temperature much faster and seek room temp even quicker than normal. The solution will be the larger heaters and/or the room temp being closer to your ideal temp. The opposite mayl occur during the summer (it will try to warm to room temp too quickly), except that you will gain a bunch of 'help' cooling it due to the evaporation. It will be interesting to see what you will experience when the room warms up too. It may be the perfect 'cooler' (like the old 'swamp' coolers we had before A/C) and you won't need a chiller even if heats up more than you'd like in the room. I agree with spreading out the heaters too warm up the water and help keep it where you want it.
Doug
 
You must log in or register to reply here.
Top