Water Changes - Large Tanks

Discussion in 'General Planted Tank Discussions' started by Mark Webb, 3 Feb 2010.

  1. Mark Webb

    Mark Webb Member

    I am about to start up a 1000 litre tank. Planning on low maintenance with Java, Crypts, Echinodorus and maybe some Moss and low lighting of initially 1wpg. Initially I will not run any CO² to see how it fares.

    I am thinking that maybe with a large tank like this, 50% water changes may not be neccessary? I will eventually stock with Discus and I am reliably informed that 10% water changes will be sufficient once per week in a large tank.

    So, I am wondering if this will be sufficient for the plants and controlling algae? The problem I have is that a container for 500 litre water change will take up a considerable amount of space in my garage, and wont be easy to heat in the depths of Winter.

    Would really appreciate some feedback as to what I might get away with.
  2. Piece-of-fish

    Piece-of-fish Member

    East London
    If you intend to go no co2 you shouldnt actually do water changes by default as it will add some co2 with the fresh water resulting in unstabilizing the system which could benefit algae. The problem here is that you want the discus witch as far as i know require quite high water quality and large water changes. Do you intend to use RO water? If you would go for angels that would solve the problem and give you really low maintenance.
    My experience is limited though.
  3. danmil3s

    danmil3s Member

    hi ive got a 750l tank so not as big but for my water storage ive buried 2 water butts about half way under ground then built ply box round them stuffed with rock wool seems to keep the cold out
  4. Robert1979b

    Robert1979b Member

    Hi Mark,
    You have'nt really given enough info for people to give good advice.
    Do you intend to keep wild (or low F number) discus or domestic forms. Wild need more exacting conditions than domestic. If you were to keep wild heckles then 50% per DAY of 95% RO is not unheard of.
    How many discus do you want and what would be the total stocking, more fish = more water changes.
    What is your water like from the tap, are you going to use RO, HMA etc.

    Like Danmil says there are easy ways of storing water outside and then use a simple pump and hose pipe into the tank. On cold days a couple of loops of hose in the sink with hot water warms it up nicely as long as the flow is not too quick.

  5. TDI-line

    TDI-line Member

    Yaxley, Peterborough
    I use to store and heat water to the correct temp, but now all i do is use a split hose with hose locks connections on my hot and cold water taps and turn on. Easy. :D
  6. JazzyJeff

    JazzyJeff Member

    Your discus wouldnt like it though lol
    Too keep discus in a planted tank you would still need decent water ie RO/HMA mix or if your lucky enough too live in a softwater area then just HMA, my 500litre discus tank got at least a 25% water change a week ..... I had adult discus that didnt need huge changes as they were all nearly full grown, if you want too grow discus on in a tank this size forget it they would need 50% a day and all the beefheart you can muster lol
    I store my water in a butt in the fishhouse as I need RO/HMA but if you didnt need that you could set up an HMA unit by the tank an drip it back in slowly !!!!!
  7. danmil3s

    danmil3s Member

    probably stupid question what's HMA water
  8. Roy S

    Roy S Member

    Huyton, Liverpool
    If you are using HMA then it doesnt matter where the water is coming from the HMA filters will remove any metals. Mark Evenden has recommended this method on BIDKA and a few people use it :thumbup: . I've got a 500 litre discus setup and even for this size tank, storing enough water for my twice weekly water changes would be a right royal pain in the bum. so I just have a hose connector onto my mixer taps adjust the temp to give me approx 84-86f out of the HMA filter, at a flow rate of around 2-3 litres a minute....job done :D Hell of a lot faster than heating stored water up with aquarium heaters etc.
    Mind you we're lucky round here as our TDS/conductivity from the tap is great for discus with no need for RO, HMA is more than adequate.
  9. Roy S

    Roy S Member

    Huyton, Liverpool
    I believe it stands for Heavy Metal Axe!. Its a composite carbon/resin filter cartridge used for removing metals and other nasties from tapwater, a lot of discus keepers are now using it with great results.

    Heres some blurb on it
    Lead Reduction Based on NSF/ANSI Standard 53

    Cyst Reduction Based on NSF/ANSI Standard 53

    Outstanding Chlorine Taste and Odour Reduction
  10. danmil3s

    danmil3s Member

    that's what it stands for the filters came up on a google search but they all said mha not the full name thanks again any way back on topic ill have to try that idea with the hose coil in the hot water im using 2 100 watt heaters at the moment heat one water barrel and the other one im just leaving only fitted it Sunday after advise from here so thats got to save money for big water changes
  11. Mark Webb

    Mark Webb Member

    Thanks for all the replies. Intending to keep domestic Discus, so long as I can come up with a workable water change regime. With a tank this size it has to be made as easy as possible or it will be a chore, but now thinking that Discus and no CO² dont mix :rolleyes:

    Using HMA filtered water. The problem with using hot water supply is that I have the cold water supply neatly plumbed in with a separate supply to the garage (where I intend to keep the w/change tank) and its gonna be messy to run another supply for hot. With this setup I can turn on the water supply to the filter and forget it, then when I do a water change I can pump out and in from a tank fairly quickly. Dont want to go down the route of feeding from the sink as for a tank of this size the filtered water can take a couple of hours to run off, so not an option to have hose across the house for that time.
  12. plantbrain

    plantbrain Expert

    Given your goals and what trade offs you seem more interested in:

    The light sounds good.
    Non CO2 methods really work very well for long term care, but then your fish need to be fed and they can be messy, so there's less room for error with food/nutrient balancing.

    There's a few ways to do this to make that part easier: more floating plants and an open top design. The plants will scrub the water clean, you'll need to add more nutrients, likely K+ and traces, and perhaps a little NO3.

    I keep L046 zebras in a non CO2 tank, do weekly 50-60% water changes, they are not needed however, I do them mostly so I can stuff the fish to the gills, and I have a large pack of RCS that eat the left overs.


    This way you can still see the fish hanging out under the mats of plants.
    There's no algae, and no need for CO2.

    If you need to do a water change, you can, if not, that's okay as well.

    That's but one option.

    Another is a pure non CO2 method, using no water changes at all.
    A Worm castings, or ADA AS sediment would be wise also, but pure plain old sand works, and you dose 2-4x a month, about 1/2 the dose volume folks use on these higher tech CO2 enriched tanks.
    It's not hard, the sediments provide a long term nutrient back up supply also.

    Here's a plain sand done using the water dosing method without water changes for about 2 years:


    Not bad, but you will not be able to over load this tank and do water changes to rectify the problem.
    Those are two options and you can blend them certainly, more % floaters make the CO2 issues go away and greatly increases the rates of nutrient uptake and removal(about 10-20X more so).

    So it's best to error on the lower side of nutrient loads from the fish, then top off with a little bit of KNO3 etc here and there.

    A 3rd option, and I want you to truly consider this not based on fear because you are unfamiliar with CO2 gas, but look at it as a good tool. Do not let the lack of understanding or experience with CO2 sway you. I am highly supportive of the non CO2 methods if that is the goal and the trades match up.

    I think you might want to reconsider CO2 based on your comments.
    It's not hard to use with the light system you have.

    Low light is ideal for CO2 gas enrichment.
    CO2 maximizes the little light you have, so the plants spend more resources gathering every last bit of light rather than stressing to get the CO2. You will have about 3-4X the growth, so it will still be slow growth, but it will allow you to grow any species and have it look very nice. So it's slow but managed growth and it also allows maximal light use efficiency. Basically you get every bit of energy used by plants that way, rather than wasting 50-90% of it since the plant has to nab the low levels of CO2 aggressively.

    So you get much more out what little light you have.
    The fish are fine either way, particularly so and much easier since light drives CO2 demand. With low light, there's a lot of wiggle room in dosing the CO2. Fish do very well, breed etc even at 45ppm of CO2, and warm temps in the 30C-31C ranges in planted tanks.

    A 1000 liter tank is a large piece of indoor real estate, I think it should be done right so you really enjoy it and it must look nice, other wise the significant other will harp. So the CO2 sounds like a good idea to consider.
    I'm not telling you to add more light, please note that. Just CO2.

    I came to these conclusion decades ago for myself and more most folk's goal, but few listen to lower light in the USA.
    Cost of energy is a concern these days, so some are reconsidering it, and algae issues etc also seem to go away very easily and never come back once they see the (low) light.

    So it's not the terrible thing you may have read about, the evil lurking under the cabinet :D

    I would suggest using a nutrient rich sediment if possible, DIY for saving $ or ADA AS.
    If you want a white sand, then the worm castings might work better for you and topped with the sand of your choice, or I just go plain dolomite sand here:


    This is a 350 gal, 400 gallon total volume.

    This tank uses CO2, but it fairly low light.

    Same thing for this next tank, which is 1600 Gallons, the angels are F1's that have never been out of this aquarium, and discus have breed many times now in this tank as well as the cories.


    The white sand front with Driftwood and epiphytes works well for the discus along with low light T5's(Gieseman bulbs have a nice look for plants and the fish). Plants are easy to keep, fish are comfy, you can feed well, they have places to pick at the food etc, easy to clean etc.

    Water changes can be done like this: 20% 2x a week or 40%. You can add what warmer water you have.........then the cold water is fine, as long as the filters and heaters are running as well. A 7-8 C drop is fine.
    The heaters will bring it up in about 1-2 hours later.

    I would suggest hard plumbing this tank to the house water for hot/cold and having a drain hard plumbed as well.
    This is well worht the cost or if you can DIY, go that route. This way all you do is a turn of a valve to drain it to 40%, then turn another to refill it. 400 liters should not break the hot water volume at your home if you have a typical water heater, mine is about that range, but it refills and heats back up pretty quick.

    Do not do the water change after showers or during laundry day.

    You can also do the slow refill method and work on the tank, prep foods, wipe glass, , check and clean things for 1-2 hours each water change.

    A pre carbon filter where this comes in from the house water line is wise also, removes organics and chlorine.
    The short term cost for the CO2, sediment and hard plumbing might seem tough.
    I can assure you, over time, it more than will pay for itself.

    I remove about 100$ worth of ferns monthly and they are bought in less than 24 hours on line for full asking price in the 350 Gallon tank. So the CO2 helps and pays for itself pretty quick.

    The reduced labor and chore, less motivation required when all you do is a valve turn make the water changes cleaner around the home/less mess, and far easier, thus more likely that you will do them. So there's a few things to consider. It's a big project.

    Tom Barr
  13. mr. luke

    mr. luke Member

    I disagree.
    Im no expert but i have a certain ammount of knowledge.
    Discus can be kept in hard tap water as long as you are sensiable and pick your discus from a good source to start.
    Discus can breed in hard water, albeit with lower brood sizes, so if you could source some of these then it would be great.
    Also, its fairly accepted that smaller discus do well in harder water as it promotes growth.
    IF you where doing your 10% changes then tap water wouldnt have much of an impact.
  14. JazzyJeff

    JazzyJeff Member

    They can be acclimatised too any water over time yes, but Discus are suspect too Heavy Metals in the water and will be affected from the inside out over a period of time, bit like us living in a smokey room !!!!!!
    For the sake of £50 you would do no harm in putting all your water through an HMA, your fish will benefit no end in doing this and they will show more vibrant colours, they will also breed in most conditions but you will get a better yeald of eggs from lower hardness water, Jorg Stendker breeds all his fish in RO water and as soon as they are old enough he transfers them too liquid rock, asian breeders Breed and keep their fish in lower hardness water as that is what comes out of their tap .......
  15. Spanerman

    Spanerman Member

    So a lower lighted tank with good ferts and Co2 will grow just as well as a high lighter but slower?

    Could i grow demanding plants with around 1.5wpg and good ferts and liquid co2?

    Sorry to threadjack, Sam.
  16. a1Matt

    a1Matt Member

    Yes and yes :thumbup:
  17. Robert1979b

    Robert1979b Member

  18. Mark Webb

    Mark Webb Member

    Tom, thank you so much for such a detailed response. I had rather hoped that you would pick up on my thread. Your tanks are stunning :clap:

    You are absolutely right that this tank should be hard plumbed. Its by far the best option. I would appreciate any tips you can give for hard plumbing the draining of the tank, i.e. where to put holes in the tank and how you deal with stopping fish going down the drain o_O . How do you do it in your tanks? One possible hitch - is ok to run hot water through the HMA Filter?

    This tank was formerly used to keep Marine Fish and had a weir in the corner. This would have been ideal for an overflow so that I could have safely left the water supply running and not worry about overfilling. However, I foolishly removed it and capped the hole with a piece of glass thinking that I would have no need for it.....WRONG! Would be a tough job to remove the substrate and attempt removal of the cap. I would now consider having the tank drilled at the top for an overflow. I guess this could be useful so that I could turn on water supply for a couple of hours and avoid draining down, although its not a problem with a good pump.

    I have no problem with using CO² and do currently use it in 2 other tanks. I just thought I would experiment and try initially without on this tank. I am encouraged by your suggestions and will now change plan A and use CO².


    I have already added substrate to the tank and have gone for Akadama. I have added slow release fertilser to the base. The cost of ADA in the UK is prohibitive on a large tank and I would have been looking at £300 just for substrate. I was considering white sand which was my preference but having asked others using it they said they would not use it again due to the clouding issue if it is disturbed, so this put me off. However, I would like to maybe move the front 9" of Akadama back and use white sand at the front - I do like the look.


  19. mlgt

    mlgt Member

    Looking forward to seeing this set up.

    Im in the process of adding co2 into my discus set up tank and have a low light set up.

    Tom suggested I can have a range of 30-45 ppm on the tank.

    This is my current layout - viewtopic.php?f=35&t=6740&start=10

    However its still got a long way to go.

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