Project Savepower with pristine water - automatic WC'er

[henward]

Hi all
I have an experiment, if someones already done it, well, then i just wasted time but its fun, remind sme of a science project.

3 trials are going to be done.

First of all, i have built an automatic water changer, that can have multiple tanks running off it, and never again having to manualy take water out and replacing them manually again. I can also programme how many litres per hour i want into the tank.

My tanks are 2x 1200 litres and 1x750 litres.

Trial is done on only 1x 1200 litres as the others are not set up.

Water in NZ where i am from is clean, no ager needed. Straight into the tank possible, but will be aerated for added safety margin.

Goal:
To find out if i can save power with heating my water.
HOW?

The heaters to maintain heat in the tanks will turn on by themselves after the desired heat is reached. Every few mins they will turn on. then if the temp is still ok, they will turn off by the thermostat. But if the temp is low, they will turn on longer.

My theories are..... these self checks/maintenance heating is enough to heat water in small amounts. The heater turns on, it doesnt contro te heat it releases, it just heats up to the rating the heater has in power...then turns off. So in essense, usualy this is used to maintain heat or is wasted - to utilise it, i experimented with a auto water changer that drips the water so minutely over a week, that no more than 1c will ever be seen by the tanks temp....

This self checking is im sure a aprt of all heaters, but i use 2x 300w jager heaters. I used to use 3x 300 watts. but cut back one for this trial, to prove that i dont need that many heaters once the temp is up to 28 to 29c whcih is where i want them.

Old method of water changing:
I remove a % of water, and replace straight after.

New method:
Auto timed and measured water injection over 24 hours.

Next post is my trials.
Please
Any comments, that would be awesome!!!!!
i have been spending abit of time on this to ensure i can fid the answer, which will in essense remove work of changing water and always having my tanks in pristine condition. also, manual changes bring down the temps by up to 6degrees Celcius - and the fish get stressed, this way, max movement is 1C and fish dont notice.

FEEDING REGIME:
My feeding is heavy, My tank is moderately to heavily stocks.

i woud feed 5 times per week, at night to my polys 1 to 1. shotglass of massivores. 2x a week beef heart. 1 day fast.

arowana eats shrimps stuffed with massivore daily and 3x a week on mealworms ON TOP of the shrimps.

all other fish are fed twice daily with floating cichlid gold.

clown loaches are fed 1.5 average times a day with sinking cichlid gold.

My feeding amounts are not light.

 

[henward]

TRIAL 1: 1200 litre tank

I have adjusted my auto wc'er to dose over 24 hours 200 litres only.
This is equal to roughly 120% worth of water turn over in the week.

The injection of water is done in 15 minute blocks - and total to 2 hours worth of water injection through out the 24 hours period. Minimum of 3 hours gap between each.

The gaps are designed to utilise the "self checks" and automatic turning on of the heaters. If i drop temps too low - i will turn the heaters on by the thermostat detecting a low temp.
But if i inject the waer slowly enough, in theory, the heaters automatic turning on to check temps and its systems should be enough to heat 25 litres per every 15 mins the water being pumped in.

In this trial, i average consistently - the power Useage of 0.665kwh per hour.

this is consistent, i leave it for a day - and sometimes come back in 2 hours....very consistent.

Nitrate levels during this trial started at 50ppm, the day of my normal wate change but after 5 more tests during the trials - the levels were no higher than 30 to 35ppm.

Temps were 28c to 29c - occasionally droppin to 27.5 to 27.8celcius, but going up to 28 quickly ( i think it was just needing the new water to circulate as my thermometer was in the sump where the water is injected.

 

[henward]

Trial 2: 1200 Litre tank

Trial two uses the same WC method of the auto changer. All parameters are the same. Heating and volume is all the same. Only difference is that i am pumping in 50% more water than trial 1 in the 24 hour period.

that brings it up to 300 litres per day. Equates to 175% turn over for the week.

Although 175% is completely overkill and not needed - all im trying to do is prove my theories of the heaters self checks. I have spaced out the gaps between the 15 minute injection of water at 25 litres approx per 15 mins to as wide as possible. So gaps are ranging from 2.5 to 4.5 hours apart roughly. 2.5 hours during the warm times of the day, and through out the night its 3.5 to 4.5 to give the heaters enough time to catch up avoiding the heateres turning on due to a significant temp drop.

If the useage of power is still 0.665 KWH, then this proves my point.
Water is cheap in my country - rains most of the time. so this s a small cost to having a tank with pristine water conditions.

Trial 2 should be done in a few days time.

I expect nitrates to be around 10ppm to 20ppm consistently.

temps should not drop much or too long below 28degrees. fluctuation of 0.5degrees c is acceptable.

although 120% is enough, and i will most likely revert back to that, if this does not use extra power, i will consider leaving it to around 140% to 150% turn over changed a week.

 

[henward]

1st day of trials
my theory might already be proven wrong, but i will wait till tomorrow.
with the extra 50% i have registered an increase per hour KWH use of 0.11 KWH per hour used by increasing 200 litres per day to 300 litres per day.

175% per week is completely over kill, i just wanted to try it out

 

[Plum]

Am I understanding correctly in that you are attempting to discover whether it is cheaper to maintain the proper tank temperature with a Auto Water Changer (which changes the water slowly over a period of 24 hours) as compared to changing (example) 50% water in an hour?

Interesting if so. I will be installing an Auto WC system also, though thought I could find some savings in Heat by either insulating the tank, or putting something arouind the side and backs to "absorb" the heat (tanks are in wall thus I can do this).

Appreciate your further commentary.

 

[henward]

Yes, what i am trying to prove is that you will use less energy, significantly less if you drop and slowly dose water into the tank as opposed to taking big chunks and replacing.

My findings so far prove this, but i have afew more trials, and i will post full conclusions.

my tank that im experimenting on is insulated with a poly later on back, sides and 20% of the top and the entire bottom if also insulated.

so my trials are consistent with myinsulation. so any extra energy use should be consistent also and show a good picture of what is more efficient as a method of WC.

i am doing my second to last trial today - should finish soon. now i have a base reading, each trial can take 24 to 48 hours only - and i can get a good result.

so far my findings are positive and shows that the water you inject into the system is not proportionate to what powre you use...basically, if you dose slowly, you can increase by alot of water injected daily but use only a fraction more power.

watch this space

 

[henward]

Results are in early.

Findings: All parameters are identical except water placement and volumes.

baseline readings of my 1200 litre is 0.58 per hour of operation.

I first tried 200 litres a day, split into 8 timed injections at 25 litres in 15 mins. Over 2 hours in the 24 hours period, and optimising natural climate and temps - i put majority of this during the warmest times of the day with minimum 3 hours average per injection, during evenings, i have up to 5 hours gap at times. this goes for all the trials.

keeping in mind, i have 2x 300 watts now, but before this trial - i was using 3x 300 watt heaters, this also when i took out large chunks of water, to heat it up as quickly as possible.

also, my 1200 litre is lined with poly on the sides, back and 20% of the top of the tank, also the bottom is fully insulated with ply and poly also on the stand.

Baseline Reading:
0.58 KWH per hour of operation

Trial one: - 200 litres over 24 hour period
new water temp is 14 to 15 degrees c
Poewr useage is 0.667 KWH per hour of operation
Nitrate max during trial is 30ppm, mostly 20 ppm

Trial Two: - 300 litres over 24 hour period
New water temp is aveage 14 to 15 degrees c
power useage is 0.77Kwh Per hour of operation
max 20ppm average 10 to 15ppm..

Trial 3: - Taking large chunks of water out at 40% 3 times weekly
This is my old method, and using the baseline reading and with a calculator for water heating - i have calculated that it would take minimum 20% more energy to heat up the water that i take out in large chunks. i calculate this as to how many KWH needed to heat up 40% at 120% of the volume of the tank weekly from 15degrees to 28 degrees. easy deductions and a figure is met.

20% is actually a rounded figure, it would be more if i take into account heat radiating out of the tank as it heats it - but in saying that, demonstrating that 20% of power can be saved just by merely utilising the heaters natural functions.

Nitrate levels goes up to 60ppm during the peak before wc, then drop sto 20ppm, then creeps up again.

CONCLUSION:

from the baseline readings, it is almost and practically heating the new water free! with only 0.1Kwh more per hour of operations to heat 200 litres a day as opposed to a min. 20% more heating used in the week period, the 200 litres a day, at 120% total weekly turnover of wc is the most economical way.

the cheapest cost to run the tank is 0.56Kwh

when i tried 300 litres per day, 50% more than 200, my increase in power was only 0.11KWH from 200 meaning that the power used is not proportionate to the volume of water, it is the timing that is crucial.

the self checks, or the maintenance modce of the heater is sufficient to heat more than 200 litres per day wiht minimal extra cost.

I can drop this to 100 litres per day and would probably use next to no extra power. but i prefer to ensure my water quality is best possible with minimising overkill. 300l/day would equate to 175% a week - too much and waste of water.

I have seen that a Auto wc'er is indeed the best option for saving power.

I have spent 330NZ dollars in setting up my wc'er - i will recover this cost in less than 3 months of operation. My power bill was horrendous!!! due to changing the water 3 times a week in large chunks.

The drum where my new water comes from is not heated, only aerated and a power head in side to move the water around. heating this drum is actually useless - because you will have to insulate it and use another heater. The point of my experiement was to prove that you can 'ride the wave' of the heaters natural functions and that i have proven with a baseline reading and the further trials. the drum will need a 200w or 300w heater, so that will just use up more power and as new water is pumped into the drum 4 times during the day, the heater will no doubt be on all the time so having a 200 or 300 w on all the time trying to raise the temps will just use more power that is wasted as the heaters natural function should hea tthe water anyways.

But, the water injected in clearly made a difference in power useage....even though it was only 0.1kwh. So I will build a portable and moveable solar heater that runs from my drum and back. the pump that will be used in this pump will be a 10w pump, and the run on a hot summer day should be enough to heat the water in the drum at least 2 to 3 degrees min every few hours - thus further helpin to reduce the power consumption.

i will apply this method in all my tanks now - further to make my tanks as efficient as possible - i have spoken with a heating and airconditioning engineer, she said to me that there are 3 heats you need to take care of.
RADIANT, CONVECTIVE, CONDUCTIVE.

Foil will takes care of Radiant, similar to a radiant heater you buy in the stores. infrared light is reflected and the heat maximised, this also works for visible light.
maximising further your insulation.

Poly takes care of only Convective and conductive.
Convective and conductive will leech through much more requiring a layer, hence the poly layer insulating that.

I will staple foil with the shiny side facing the tank under the poly also, to maximise my heat retention, this should save a few $$$ a year. also, during the coldest of months, this will help retain heat.