Undergravel Heating Cable vs Temperature

[simfish]

My temperature is between 27 and 28 degrees. I am using an electronic thermometre. I had 2 new heaters. One Jebo which disconnected and the other Rena which I have turned down to 24 deg. However the temperature is still up there. Because I have my sand substrate setup as rolling hills some places thinner than others. Could it be too thin in spots i.e. about 2 to 3 cm and therefore getting higher temps. I have been monitoring the Rena and it sits dormant I think. My undergravel system is the JBL Pro Temp Basis 250. any ideas how thich the substrate should be so that it does not affect the temp too much....

[Ira]

People still use undergravel heating cables? I thought that fad went out in the 90s? If your tank is too hot turn the heating cables off, they're not necessary anyway...

[alanmin4304]

Do you use under gravel heating cables or are you measuring the temperature with an electronic thermometer?

[alanmin4304]

Sorry. If in doubt read it again.

[simfish]

I use undergravel heating cables. If you dont use that how would you get upward convection flow of nutrients and heat for plant growth and did you know heating cables have a significant influence on the lack of algae.

[Alan]

Where is the thermostat sensor?

And is that last statement a selling blurb on the box or is it factual, if so, where do you find that info??

Alan

NZKA 104

[simfish]

Half way relevant to the water in the middle of the tank with the heaters at each corner.....

[jamestothemax]

i dont know about the reducing algae thing

but from what i understand because there is no water movement within teh gravel the water there is nable to be heated effectively by the heater so gets cold.

as heat rises this means the cold water stays in the bottom and so very little new water containing the nutrients we so feverishly add daily/weekly does not get to the roots where the plant absorbs so much of its food.

because the heating cables are right on the bottom of the tank it heats the cold water making it rise, creating the convection current simfish mentioned allowing teh transfer of nutrients.

This is the theory i have read in a few books but i guess the best way to test it is to measure the temperature of the bottom peice of glass of your tank compared to the side? hard to do considering most are sitting on polystyrene.

Another thought i had was perhaps a undergravel filter system running in reverse would have a similar effect in dispersing the nutrients to the roots. anyone tried it?

[suphew]

Personally I would consider using convection currents (wether using UGF or heater cables etc) to drag nutirants to the root system should only be used as a bandaid to not having put the nutriants in the substrate to begin with.

To me logic say's to keep as much of the nutriants out of the water as possible, for two reasons, because you can run higher nutriant levels with out algae having access to it, and secondly cause its heaps cheaper to add some clay etc to the gravel when you setup the tank than having to constantly add expensive chemicals later on.

Anyway, is your heating cable on a thermostat? If your heaters arn't coming on then its pretty much got to be whats causing the problem (unless you have powerful lights??), the heat from it has to go somewhere, if you increase the depth of your substrate to reduce the heat getting into the tank wouldn't it also reduce the amount of water flow, defeating the reason for having it?

[jamestothemax]

good point nothign beats a good base to start off with.

altho surely eventually all teh nutrients from your base would be used up and the addition of nutrients to the base would become important to continue excellent growth of plants.

I'm not to sure how long this would take tho?

[alanmin4304]

I add trace elements to the substrate when setting the tank up and I leave the rest to God. She is a very clever lady and gave us fish to add nutrient and CO2. If we stopped being such clean fanatics and allowed some mulm to accumulate around the root zone and slowed up on siphoning it all away we would end up with happier plants with or without an electric blanket, and a good dose of all the bacteria that fit so nicely into the nitrogen cycle.

[suphew]

Ditto,

I found my tank was fine for about 1.5-2 years before I started getting shortages of some nutrients, I found potasium was usually the first to go, shown up by brown spots on the leaves.

All I added was about 50/50 mix of dyltons aquadic clay and gravel, then 3-4cm of gravel on top to stop the clay leaching out.