Planted tank and water changes

[Rclarkie]

I have enjoyed exploring the site and have found it to be very helpful in getting me started in the world of discus keeping. The question I have is this - I have a 90 heavily planted tank that is about 2 years old. After about 6 months I removed the hob filter that i seeded the tank with and my parameters have been spot on since. In fact I have not done a water change in 18 months only top offs. I have 30 fish in the tank from bolivians, neons, columbian tetras, guppies, and cories. I was hoping to add about 5-7 discus but everything I have read tells me I need to do regular water changes.

So this brings me to my question. What is the purpose of the water change and why make a water change if your parameters are good and stable? I would really like to keep discus but if water changes are mandatory am not sure I will be able to.

Any and all comments are welcome!

[LoGeek]

Your tank might be in balance right now, but adding discus will drastically increase the bioload. They are big fish that needs lots of food and your tank will not be in balance anymore. Furthermore, they have greater demands for high water quality than your current stock.

If you are not able to do frequent water changes than you probably should stay away from discus.

[bluelagoon]

When you say balanced.What are the readings?TDS,nitrates,PH?What are you using to keep the PH from crashing.Some tough little fish you have there.18 months with no maintenance/WC must be like swimming in a toilet bowl.A discus would be more like WC's every 18 hours.

[Rclarkie]

Good morning Bluelagoon thanks for replying - my ph is steady at 7.4, amonnia is 0, nirtrite is 0, and nitrate is between 5-10, water temp is 82. I tap off with half ro/tap water when needed. There are a large number of plants and a large piece of driftwood and the tank's substrate is dirt and stone. I have 4 T5 lights that run 8-10 hours a day. There are also 2 powerheads to providde movement and 02 as well. I have been following the Walstad method. I have had very few deaths actually none in the past 8 months or so and my cories spawn regularly.

So this takes me back to my original question if my parameters are stable and I test every 4 days whats the purpose of the water changes.....aren't the parameters more important. As far as the left over food the it is converted into needed nutrients.

If you bioload isnt exceeding your cycles capability why change the water? Please explain the history of water changes in respect to discus.

Again thanks for replying!

[Rclarkie]

good morning LoGeek - I agree adding that many large fish might temporarily knock my cycle off course - but lets say I am capable of maintaining it could it be done?

[bluelagoon]

There are still DOC and TDS to contend with.What are you doing about those?

[Jack L]

i'd like to see a pic of your setup if you'd post it.

I've read her book, and many others. I personally think it could be, but in a much bigger tank than that.

i grew out in a planted tank with a large sump, about 2x the volume of water you have. as the fish grew and size of feces grew, the water went foul fast and required many more WC than i wanted to bother with frankly. having the plants, stones and wood made it all the harder to vacuum off the sand too.

what is your substrate?

if i were you, i'd get a simple bare bottom setup going and grow them out there, then after grown add them to your planted, see how the walstad method handles that.

I have had a tank that was so packed with plants you could not even see the fish, but still, that setup couldn't keep up with a medium fish load. i saw cories hemorrhage and die from high nitrates. i tend to stock on the heavy side. in your setup, you have a much lighter fish load than i end up with. Discus make a lot of bioload.

[Rclarkie]

well the dissolved organic carbon is being used up by the plants and helps with good bacterial growth - it must not be much of a factor because my ph is stable and as far as the total dissolved solids that are in the water my hardness hasn't changed overtime either....although I add ro I am also using tap to replace any minerals and such that might be lacking......

so what do you think if I can maintain my parameters and my cycle can keep up with the added livestock can it be done?

[TexMoHoosier]

I've had planted tanks for a number of years and started with discus about 6 months ago in a high tech planted tank. If you keep your params stable and you are very capable of keeping a planted tank, the discus are actually the easy part, but that's easier said than done. When you're talking about discus in planted tanks, you have to be considering adults only, so buy the biggest discus you can afford. Don't expect any more growth after you add them to your planted set up. As far as water changes go, I use the EI method and do a 50% water change/gravel vac once per week and usually 1-2 25-50% change throughout the week. I do not believe that the Walstad method will work with discus in a 90 gallon, even if you only had a pair of discus and no other fish. Without large and frequent water changes, I think you'll probably run into more water quality/algae issues with a low tech system because of all of the excess nutrients and dissolved organic compounds. Discus eat a ton and produce a lot of waste. You will probably need to reduce the bio load you have right now to a few dither fish and scavengers and maybe 7 or 8 discus. In general, you'll battle 2 things with discus waste in a planted tank: 1) dissolved organic compounds from decaying protein (hence my extra 2 25-50% WC's) and 2) food debris/detritus on everything. Notice I did not say nitrates and phosphates. People on SD will tell you that less nitrates are better, but that only applies when the nitrates are from fish waste/decaying food (most people don't realize what they're doing is using nitrates as an indicator of dissolved organics, which are the real culprit, you could actually dose nitrates up to about 40 ppm and have no ill effects on your discus). You'll probably dose more nitrates and phosphates along with trace elements, although you'll modify the amount of nitrates you add since discus are heavy protein eaters.

So, long story short, I recommend learning all you can about EI, CO2 as a limiting nutrient and keeping a planted tank (besides using the Walstad method), get your tank and new method stabilized, and go with large/adult discus.

[Jack L]

well the dissolved organic carbon is being used up by the plants and helps with good bacterial growth - it must not be much of a factor because my ph is stable and as far as the total dissolved solids that are in the water my hardness hasn't changed overtime either....although I add ro I am also using tap to replace any minerals and such that might be lacking......

so what do you think if I can maintain my parameters and my cycle can keep up with the added livestock can it be done?

if you are asking if your setup could handle the bioload of Discus, it would be hard for me to imagine it working. you could always try it, just keep the spare ready to hold them for when your 90 starts smelling like a sewer.

one day i might try it with a 220 or something and a small discus school, say 6, and no filters but plants. but i know my 140 w/ plants AND sump, could not keep up.

[Jack L]

I've had planted tanks for a number of years and started with discus about 6 months ago in a high tech planted tank. If you keep your params stable and you are very capable of keeping a planted tank, the discus are actually the easy part, but that's easier said than done. When you're talking about discus in planted tanks, you have to be considering adults only, so buy the biggest discus you can afford. Don't expect any more growth after you add them to your planted set up. As far as water changes go, I use the EI method and do a 50% water change/gravel vac once per week and usually 1-2 25-50% change throughout the week. I do not believe that the Walstad method will work with discus in a 90 gallon, even if you only had a pair of discus and no other fish. Without large and frequent water changes, I think you'll probably run into more water quality/algae issues with a low tech system because of all of the excess nutrients and dissolved organic compounds. Discus eat a ton and produce a lot of waste. You will probably need to reduce the bio load you have right now to a few dither fish and scavengers and maybe 7 or 8 discus. In general, you'll battle 2 things with discus waste in a planted tank: 1) dissolved organic compounds from decaying protein (hence my extra 2 25-50% WC's) and 2) food debris/detritus on everything. Notice I did not say nitrates and phosphates. People on SD will tell you that less nitrates are better, but that only applies when the nitrates are from fish waste/decaying food (most people don't realize what they're doing is using nitrates as an indicator of dissolved organics, which are the real culprit, you could actually dose nitrates up to about 40 ppm and have no ill effects on your discus). You'll probably dose more nitrates and phosphates along with trace elements, although you'll modify the amount of nitrates you add since discus are heavy protein eaters.

So, long story short, I recommend learning all you can about EI, CO2 as a limiting nutrient and keeping a planted tank (besides using the Walstad method), get your tank and new method stabilized, and go with large/adult discus.

Tex, is your tank pics on here somewhere?

[Rclarkie]

Hi Jack I will post a picture of my tank later today when the lighting is a bit better to take picture. I see your merit in a grow out tank for sure. I used organic potting soil and rather large pebbles for the substrate. I ve had very little algae growth and the cories are doing a great job with the left over food - still getting the hang of feeding the fish rather then the tank...lol. I have been keeping neons solely for the nitrate build up I like to think of them as my tank canaries!

What other books would you recommend me to read?

[Rclarkie]

thanks Tex I will check out the EI method.

[bluelagoon]

I have done both methods in tanks years ago.And they do work well.The EI method for adult discus does seem to work;at least it did for me.I got tired of the maintenance and went back to simple discus keeping.The tank I did nothing with and only top offs only had a light bioload and not discus.WC's seem to be a the key for young healthy discus.

[Filip]

The main reason that discus requires much more WCs than the rest of the freshwaters is their non compatible immune systems with the pathogens that thrive in a a high PH water environments .
Simply put , they originate from Amazon waters with very low PH where the number and the species of bacteria and pathogens in water is far more restricted than in our PH 7 tank water . Their immune system is made accordingly , and can't put up with bacterial counts in our tank water .

The result of keeping discus in a planted , dirty bottom tank without many Wcs and cleaning is ussualy compromised immune systems and discus oftenly getting sick from different diseases .

[Rclarkie]

Thanks Flip that makes perfect sense! so it would be advantageous to maintain a ph of 6 - everything in the tank including the plants would prefer such - if possible.

[Filip]

Thanks Flip that makes perfect sense! so it would be advantageous to maintain a ph of 6 - everything in the tank including the plants would prefer such - if possible.


Well not really .Theoretically in order to get the desired non bacterial/ non pathogen very acidic environment for discus you'll need a pH much lower than 6.0 , I would say more about 4.0- 4.5 pH range.
And that kind of water is immposible for us to achieve in a small closed system , first because it would be a very hard to keep a water with pH that low cause it is very unstable - you risk PH crash (further sudden drop of pH ) and second with PH that low nitrosomonas and nitrobacter die off and you are back again with a problem of ammonia buildup .

So theoretically if we are able to keep pH 4. -4.5 with no ammonia buildup and pH crashes , maybe we would be able to keep discus without so many water changes , but unfortunately we are so far not able to do so, and that's why we are stuck with keeping the tank and water as sterile as it can be performing lots of WCs and lots of cleanings .

[TexMoHoosier]

Jack - I'm in the middle of re-scaping my 65 gal discus tank and a 29 gal soon-to-be shrimp tank, so I'll post some pics when I finish. The discus tank became a dumping zone for all of the plants that I didn't know if I wanted to keep.

[TexMoHoosier]

Thanks Flip that makes perfect sense! so it would be advantageous to maintain a ph of 6 - everything in the tank including the plants would prefer such - if possible.

That's playing with fire if you don't know what you're doing and there is really not much benefit to messing with your pH.

I don't totally agree that substrate houses an excess of pathogens that are waiting to attack healthy fish. Sure, there are pathogens there, but many also live in/on the discus itself, but if the fish's immune system is not compromised, they're held in check. I think the real reason people run into problems with substrate is that waste is not broken down quickly enough, excess dissolved organic compounds become toxic and other irritants affect the fish. When this happens, the fish's immune system has to kick into high gear ultimately weakening and allowing pathogenic organisms that are normally present to be a problem. This would happen regardless of an acidic or neutral pH.

[Rclarkie]

Thanks for all of the info it is certainly food for thought!

[bluelagoon]

Also,in the wild the water or pools in the dry season become very acidic where discus live.There may be lots of decay and ammonia present but the water is so acidic that the ammonia becomes non toxic.

[Jack L]

Jack - I'm in the middle of re-scaping my 65 gal discus tank and a 29 gal soon-to-be shrimp tank, so I'll post some pics when I finish. The discus tank became a dumping zone for all of the plants that I didn't know if I wanted to keep.

Thanks for mentioning EI, for some reason this time when i read about it(not the first time), it clicked, buying minerals, will give a try.

[Filip]

Thanks for mentioning EI, for some reason this time when i read about it(not the first time), it clicked, buying minerals, will give a try.

EI is an excess dosing method mainly recomended for a full blown high tech planted tanks . Meaning lots of light , lots of Co2 , rich nutrient soil , tons of plants , weakly trimmed bags full of plants etc , etc.
Its not something that you want in a low tech planted discus tank .
Try PPS-Pro if you like to start mineralizing, its moderate dosing system recomended for slow growing systems like low tech tanks.

[bluelagoon]

You can also use the EI method in a low tech discus tank.I have and with no CO2 or rich soil.The water gets changed just as any other discus tank.The chemicals are cheap if you buy them in the right place.I trimmed weekly and even some red plants did well.

[LoGeek]

I'm not experienced with discus, but I am with all sorts of planted tanks. You can definately do EI in a low tech tank. You can use the method in any tank with plants as long as the water changes are performed.