Jump to content

New tank + Water Changes


Recommended Posts

Hi all,

I have a nice new 6 foot display aquarium sitting in my living room as of today. It's completely empty and I'm looking forward to changing that. I got a huge (must be 70cm high) filter with 5 or 6 layers of filtration in it to do the dirty work, and I've been thinking about my pet peeve (but necessary evil) of water changes. With the sheer volume of water that will be in this tank, I feel for my poor little gravel siphon, my buckets and me having to try to change out so much water every change.

It got me thinking...

I have read that undergravel filters are generally considered a nono, that they get clogged up or they just don't do as good a job as other filtration methods. I am guessing that in the case of most UGF's, the vaccuum/suction of water down through the gravel and into the filter is not strong enough to do much other than move some water through the tank, and that most 'debris' that isn't the actual gravel can just build up and cause issues.

So, I was wondering if anyone has tried something like this:

Install a similar flat undergravel device with holes small enough to not pull gravel into it, connected to a water pump. run your water line outside to your garden/drainage, then turn the water pump on and essentially remove your 'water change' water by sucking (with a considerable amount more vaccuum from the pump) this water and debris (fish poop/any stray food etc) through and into the undergravel device and straight out the pump to the garden/drain. Turn it off when the water level has dropped to your desired level, then you can go ahead and top up the tank with your treated water to finish the job.

I am hoping that having a pump suck the water and crap through this undergravel plate and out of the tank would really work for getting rid of a lot of the residue that floats to the bottom of the tank, in a way that won't risk fish (they won't be sucked in), and will make for easier work.

Potential setbacks:

Not enough suction to draw debris/dirt through the gravel, would it need to be stirred etc like you do with the gravel siphon to loosen the debris before it will suck through the pump?

Undergravel plate gets clogged up. Could this happen even if the pump is considerably higher pressure than a regular air-pump or powerhead used for a standard UGF?

Noise. Would this sort of pump be too noisy and scare the crap out of the fish?

Is gravel inhabiting bacteria able to be sucked off the gravel and out of the pump in this way? (I doubt it but don't know for sure)

Anything else I may not have thought of?

I know I am still just new to fish keeping, and I'm sure someone has tried this before... What do you guys/girls think? Is this feasible at all?

One of the main reasons I wanted to consider it is that I wanted to put quite a few largish ornaments that fish CAN swim into/through, which would mean that there is quite a lot of area that I can't get to with my gravel vac without pulling the ornaments out... I thought doing something along these lines would allow a good, level distribution of suction through ALL of the gravel, leading to a better removal of debris from all of the gravel.

Anyway, please have a think about it and let me know if you believe this could work. For all I know people are already doing it this way, but I have done some searching around on Google etc and haven't found anything along these lines mentioned.

Your helpful ideas are much appreciated.

Kind regards,


Link to comment
Share on other sites

Guess the big question is what sort of fish are you stocking it with. If you have cichlids, they stir the gravel constantly with there digging. All large tanks I know have there wc done with a garden hose. Put one end in, turn tap on enough that water has a flow happening then pop it off the tap and it starts siphoning out itself. Undergravel filters are useless IMO. My biggest concern is that it will block up.

I never worry about the gravel too much, if I get a bit if build up, next time cleaning, I stir the gravel with my fingers while holding the siphon hose.

Link to comment
Share on other sites

Also if you plan to have plants their root systems will clog up an UG filter quite quickly.... for one pump to suck the insides out of a 6ft UV filter - sorry it just won't do it efficiently enough.... you could try reverse UG for cleaning but not for water changes....

Bets way to water change without buckets is still the gravel vac with a long hose out to the garden.... the longer the hose the slower it will siphon so it won't suck the insides out of your tank while you casually move an ornament or rock or two while you vac the gravel....

Once you finish with the water going out.... just attach to a tap and turn it on and you have water going back in without buckets..... I have a carbon filter on when I put the water back in then there's no real need for chemical de-chlorinators....

Link to comment
Share on other sites

Thanks for the replies. Ok the idea of the undergravel sucking doesn't look like it'll work then. Putting the new water back in then, I would need it filtered/heated first. Is a carbon filter enough to make tap water ready for the tank? How about setting up a "sump" of sorts, with the filter material and a heater under the tank, with a pond pump to pump the filtered water into the tank? That way you could fill the "sump" tank with tap water, then pump it through the filter medium and up into the main tank once it's the right temp/ph?

Maybe more work than just doing it with buckets? :)

Link to comment
Share on other sites

If you mean a sump to filter the 6ft tank - you need to get someone to drill the 6ft tank and then get the plumbing done to drain to the sump and for the filling as well.... takes a few tweaks to balance the system but not too hard to do.... if you don't want the tank drilled you can organise an overflow box type arrangement but need to have it setup well so that the tank doesn't drain if the power goes out to the return pump..... a good sump setup is great filtration for a large tank and easier to clean and maintain than a canister filter.... you will still need to gravel vac the tank though but topping up the water can be done via the sump....

a carbon filter will remove chlorine from the water (might not be so good at chloramines) but I haven't had any probs with my fish for years using the carbon filter on the end of the hose with an extension hose to fill the tanks with.... as long as you're not doing massive water changes it doesn't really matter that the water is cold... the tank heater and existing water soon comes back up to temperature - in a 6ft tank you will probably only change out 100 litres at a time and the remaining 300-400 litres will not drop in temp that much with a water change .....

either way.... you will need to siphon water out of your tank and dispose of it and find a way to provide new water to the tank system ( a sump won't remove these requirements)....

Link to comment
Share on other sites

Can you somehow hook a system up like this?

Big tank -> down to small tank underneath -> cannister filter -> back up to big tank

And have this run continuously to move water between the tanks and through the filter? If power cuts, would there be a siphon problem or would the filter keep it in check since it'd not be running?

Still trying to get my mind around it all... Sorry!

Link to comment
Share on other sites

ok... have scrapped the idea in favour of just running a big cannister filter with some creative plumbing to allow me to A) pump water from the running system out a fixed pipe to the garden instead of back to the tank, and B) use an additional line connected to a gravel vaccuum to siphon water out through the same fixed pipe.

This in combination should make my water changes AND gravel cleaning quick and easy.

Given that the tank is 450+ litres, I believe (have been told) that a 20% water change with tap water poured directly into the tank will not be bad for the fish. Maybe I should consider running the tap water through a carbon filter like you suggest anyway fishbites?

I'm so excited :)

Edited by Nokternl
Link to comment
Share on other sites

If your living in Perth you really should not be draining your water into the garden/drain as I assume like here it goes into storm water not sewerage, this is how things get introduced into our waterways

I connect a hose to the lauandry tap with a click on adapter from bunnings to fit a std click system hose and fill directly with warm water. and another hose to drain out the door, not all that hard

You can fit auto fillers and overflow systems depending on your setup

I heard of someone recently who run there old water through the wall to a pump that pumps it into a tank and then gets reused in the toilet

also work well but not sure where you buy but have used a cheaper copy before



Edited by pritch33
Link to comment
Share on other sites

I was just thinking that the nutrient rich water would be good for the plants in my garden... and that it would be a waste of water to just put it down the drain. :(

My tank is now fully plumbed, using a cannister filter and a series of retic taps. I can have it running as normal, or open a tap to have the cannister pump water down and out of a hole in the wall into the garden. In addition to this, another tap will start a big gravel cleaner to allow me to clean gravel and outlet it down the same pipe through the wall. It's usually better for me to turn off the cannister once the gravel cleaner siphon is running as it is WAY too fast draining otherwise. :)

Seems to work well, am happy with the setup, and can use a hose easy enough to top up. I will have to see if there is any other option for drainage. There is the downpipe drain from the roof guttering, but I assume that goes to the same place as directly into the garden (with the added negative of not helping the plants)?


Link to comment
Share on other sites

  • Create New...