RO or RODI/ trace minerals/ drip top off and other questions

[oliverk]

Ok so it seems that most of the forum is of the mindset of take out and replace water with new water.

Physically, I think I can do this once or twice a year but am hoping to do less.

WHAT I CAN DO is allow evaporation and plant respiration to use a lot of water in the system. Indeed I plan on doing aquaponics and perhaps having an uncovered aquarium/sump. Am planning on adding water as needed from RO or RODI system to top off the system, and perhaps do "overkill" on filtration - plants in hydroponics run and a normal wetdry/sump.

Now I know that inland seas like the Great Salt Lake become progressively more salty and "trace" mineral dense as water flows in and evaporates leaving the fresh water salts and trace elements from the incoming water in the lake. However, I plan on using very clean water RO or RODI so very little additions to the trace stuff.

How much will the fish, the plants in the aquarium, and the roots of the plants in the hydroponics portion of the aquaponics system actually consume and remove? In otherwords how often will I need to use something like Kent RO Right to boost the trace elements from actual consumption or evaporation?

Am assuming that evaporation and plant respiration will consume enough water to give me at least a 50-70% water extraction per week and that biproducts of the fish waste will be consumed by the hydroponics filter(s) (gravel, roots, plants etc) so its a water change - right - that leaves the trace minerals and salts that were originally in the system - except of course those actually consumed by the fish and plants. How much will I need to replace, how often and how do I test?

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Have seen many posts that the trace elements are necessary for good discus health so what would those levels be, how often do they need to be checked and ........?!

oliver

PS what is in evaporated highly filtered water that would need to be extracted if you don't think simple replenishment will work...... remember I have a full sized wetdry/sump and a full sized hydroponics system eagerly seeking all of the "nutrients" or waste in the water that have been produced by the fish - or other things of an aquarium

[sdrexler078]

So you aren't going to do water changes?

[oliverk]

Well I am expecting a substantial amount of the water in the system is leaving slowly per day - plant respiration and evaporation and I plan on adding replacement water.

Water out and water in = water change

Am hoping not to have to do manually and etc

[sdrexler078]

The best way would be drill tanks and have it so you can turn valve and drain then turn valve to fill. What you're talking about is not a very healthy to never change it. Nothing is better than manual changes but you can make water changes very easy. I have a transfer pump that sucks the water down in minutes and then another pump in my aging barrel to fill it up in mins

[sdrexler078]

Without water changes your fish will more than likely not live very long. Even with adding minerals you are never removing any of the bad things

[klannin]

Why would you use this approach with one of the most sensitive species. I suggest you start with a gourami or something. If the poor fella lives after a few months have the water analyzed. Compare it to the tap, that most people use to keep discus healthy, and go from there.

[Second Hand Pat]

Hi Oliver, discus need lots of fresh, clean, warm water. I think you would be better off running your system off something like Tilapia and leave the discus in a more traditional tank setting.
Pat

[oliverk]

Hmm every thing I read says make the changes slowly so that water doesn't have sudden shifts in its composition. I know of no better way to increase the likelihood of changes in composition than to remove a 1/3 to a 1/2 of the water and replace it with something else. Sure you can do the best you can to match the water but by definition you are mixing two waters to create a new one.

My approach does has lots of clean fresh water in in it - am doing on the order of 50 to 70% or more change a week. During the summer I would expect to reach more like 125% a week, albeit relatively slowly which will prevent sudden changes in quality.

Think of it like this you walk by the tank 50 times a day - every time you go by the tank you take out a quart and put in a new quart, that's 50 new quarts a day, that is a change of 12 gallons on a 120 gallon tank that is a 10% change every day..... 10 days gives a 100% change. That is a lot of new water in the tank.

My water goes out side and plants eat it, lots of stones, or vermiculite, lots of surface area for evaporation. I lose to plant respiration and consumption a bunch of water and the new incoming water is fresh clean RO water which is pretty close to H20 without anything else in it. That is very clean water replaced by water lost to plant respiration and any particles in the water a lost by probably twice to three times the amount of filtration most are doing - I want all those nutrients for the plant growth and vegi production.

Will say this many many, many commercial production houses for fish use this method of filtration and the fish are approved for human consumption.

Have talked with at least one discus pro and he thinks the method stands a very good chance of working well - his concerns were algae blooms (uv sterilization), temp control (in line heater in the return plus heaters in the sump and aquarium as needed)

Had hoped someone had definitively tried this and had an opinion, not a Knee Jerk reaction of - not what I'm used to, won't work etc. closed down response approach.

BTW am very sure it won't work for most of you because you need to connect the tank to something like a +/- 1 ft of growing space to each inch/gallon of fish. So if you have a 100 gallon tank you have the benefit of 100 sq ft (note will be going between 6-18" deep) of growing "grounds" and should be dong close to that to clean the water properly for the fish and you have enough nutrients to feed that many plants. The 100sq ft can be water and roots, gravel or vermiculite or perlite or or or with roots and water flowing through it etc yep you need to aerate the plants as well, so ......

Now think about the filters on your aquariums how many cubic feet of filtration of active (surface plant extraction) bio (normal biological filtration) and mechanical (bio balls, gravel etc) filtration do you have? My filter will be on the order of a cubic foot per fish inch/gallon of water and am going to be adding lots of very very clean water to the system - but slowly.

Lets see a 120 gallon tank often has what a 20-40 gallon sump that includes a refugium and etc..... Maybe a cubic foot or two at best of real filtration and none of it growing plants that are actively seeking every scrap of nutrients (cleaning the water) to grow - you have small bacteria on the bio balls. Great they work, I have them too, I have a full size wet dry at the end of my 100cubic feet +/- of other filtration growing grounds before it gets to the standard wetdry/sump.

The filters we are talking about are very different in size and scope, Sure what my plants extract and the rates will depend on the type of plants and mix of them but my question was about evaporation alone on a massively large filtration bed like the one I am thinking about.

Might not work, but there is lots of precedent that says it will. Unless you have a green thumb and want to grow your own veggies and have the space the system wont work for you.

Wish me luck and help me figure out how to make it work if you can!

thx

oliverk

[Second Hand Pat]

Read this to understand how water changes work over time. http://www.simplydiscus.com/library/..._formula.shtml.

[oliverk]

Hey thanks for this article.

It seems like the waste build up/reduction is for a tank without any filtration, plants in the tank, or cleaning fish in the environment. Assuming, of course, that the article is accurate this provides a great baseline of understanding of the waste build up in an unfiltered uncirculated tank ----- Not sure if there is a difference in type of waste - some waste it seems to me is more liquid than solid and some has a solid component that may sink - at what rate I don't know but hey it is a simplistic baseline and useful as such.

From this baseline lets think about filtration - there are many types of varying degrees of efficacy. I'm sure most in this community are doing at least some for of filtration, supplemented by water changes of fresh clean or treated water.

Hey what about this as an overkill hands off system? Lets put tap water and your aquarium water mixed oh say 3 parts tap 1 part aquarium through a FULL RODI filter with a capacity of 30% of your display tank per day and assume we trash the waste from the RODI. Suspect this community would say more than enough filtration/water change - perhaps too much - you need to add supplemental trace minerals back into the system.............. This could be automated - even the trace add backs - probably not cost effective or ideal, but...... Think about how much water is being replaced, filtered and changed with the 3:1 waste to good on most RODI systems.

Suspect even the most die hard of the bulk water changers would go this automated system should be enough...... Way Way overkill and compensation for the overkill of filtration.

So where is the balance between types and amount of filtration and types and amount of water change?

Ah am sure most people in this community are doing very very good filtration AND enough water change to keep the water pretty clean even without ANY filtration. Again perhaps maybe overkill, but ...........

I however am disabled and want to set up a reasonable automated system that also produces great vegitables for my wife and I to eat. The system I'm thinking about merely has a whole lot more filtration than most and a slow extended replacement of water leaving the system rather than a bulk sudden change of water (that I do not have to manage carry etc). Am hoping the solid waste will be addressed by the cleaner fish, the plants in the aquarium, be suspended enough in the tank to be extracted to the massive filter (am thinking about doing trying to figure out various types of "overflow extraction" that may get semi solid sediment lower in the tank) and etc.

[Second Hand Pat]

Oliver, have you kept discus before?

[kris2341]

Given that the OP is disabled but STILL wants to produce a compromise that can give solid results for him in a first time discus keeping endeavor, all i can really say is that he will need some kind of fully or semi automated water change system that can drain the water, and put tap water back into the tank.

As far as using an RODI filter, that is absolutely unnecessary for simply keeping the fish, and it is not feasible or recommended to put aquarium water through one end as it is simply not clean enough and you will very quickly ruin the prefilter unless you have a VERY robust supplemental prefilter and a whole lot of pressure.

RODI filters generally require household water pressure and the pumps needed to do this use more power than it is worth.

Throwing aquaponics into the mix sounds like quite the risk since you basically need to balance the nutrients the plants need and the needs of the fish. It is a very fine line, too little and your plants will not grow, too much and your fish will die. There is also the complex issue of microbes growing and could cause your fish to become sick which can come from the plants or the growth media of choice that you use.



In short, keep the two separate, If you want a fish more friendly to things like aquaponics yet are colorful, get some quality african cichlids. I cannot recommend a system like this for discus due to the extremely high chance of poor water quality.

At best, the system can keep a group of healthy, strong adult discus alive, but it wot be able to grow out fish without a lot of new water going into the system. But we are talking discus that go for $150 a pop, do you really want to risk it?

[oliverk]

Some sort of automated or semi automated change - the first I have to figure is how much I am losing naturally through evaporation and plant respiration - a lot especially in our warm spring summer and falls here in Houston. My uncovered 20 gal tank loses a quart a day inside. I'll have 30-40 sq ft uncovered probably and a 40-60 sq ft of covered additional filtration but there will be plants respirating - eg taking up water and exhaling water vapor and oxygen etc. It is very easy for me to believe that I'll be losing 10 gallons of water a day just due to that.

Its easy to do put a liquid only plant growing tank in the first position after the overflow from the aquarium. Put a float valve in the tank when water level gets too low add new water. OK so I'd like to add from the house hold system - means at some point I have to filter/treat the water - lets assume it is RO + or RODI water, or other sediment and carbon filtration sufficient to clean up water for the fish. (Still selecting the final system(s) and installing the systems and stabilizing the tank and plant filtration before putting in discus - am treating water in the meantime with a sump - its killing me - and hate having to ask others to help but do mostly).

May need to get a water meter to see how much treated water is flowing into the system, but anything above oh say 5 gallons a day would do pretty well. I have a 120 gallon tank with wood, plants and gravel in it. so probably more like 100 gallons of water. 7x5 = 35 gallons of new water a week in the system or a 35% replacement of water.

I find it very unlikely even in the dead of winter that I will use less than 5 gallons a day.

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So my original question is that trace elements don't evaporate or respirate, they are consumed somewhat by the fish and the plants. I don't want to continually add some thing like RO Right, problematically

[kris2341]

Let me just say this, as far as evaporation is concerned, it is best that you DO NOT consider evaporation as some kind of water change to ANY extent simply because of what it is.

to put it simply, when you evaporate water, everything that is not more prone to evaporation than water stays in the liquid water, so all minerals, dissolved organic compounds and waste products stay in there in ever increasing quantities and add to the problem. This is the reason why we actively take out water from our tanks and facilitate a water change, we need to remove these compounds that dont evaporate with the water.

as for plants, they generally take up Nitrogen, Phosphorus, and Potassium as main nutrients along with Carbon. They also take up a number of micro nutrients but these numbers are usually too small to make a significant difference in the aquarium. The fish and plants do not absorb these nutrients in equal quantities so you would be subjecting your fish to severely unstable conditions with excessive nutrients in one regard and a deficiency in another.

The water would inevitably wind up extremely HARD, and will suddenly shift in all sorts of directions as you put in RO water.

The key for you is to somehow guarantee perfect water stability but you cant really do this to the degree discus need with this system unless you totally trash the idea of using RODI water and use a special GCAC + zeolite filter to perform a constant water change to a MUCH greater degree than what you suggest

[doublediscusjack]

Oliverk: I know a veterinarian who developed and ran a system much as you are describing, but he was successfully raising some sort of human food fish in it; certainly not discus. I tried to do something similar, but with, in addition, dedicated sophisticated chemical filtration as well, with discus, with limited success. Discus didn't sicken over time; thrived well for years under system, but their spawning wasn't "normal," so getting much normal hatching, normal parental feeding, etc. wasn't possible, compared to discus raised in more traditional ways. Too, getting normal discus growth was not normal either, compared to system using wholesale water changes. What you suggest sounds reasonable, and sounds as though it should work, but the theory of your system doesn't stand up to putting it into practice. However, it sounds as if your mind is already made up, and that you will move ahead no matter what anyone says. The path you are about to take requires many complex issues, many of which will be shown as you proceed, requiring you to deal with such issues, probably costing you a fair number of discus lost due to a variety of issues you didn't perceive earlier. For man to try to duplicate nature on a small scale, such as what you suggest, is way more complex than it seems. However, let me wish you well. One thing I can guarantee you is that you certainly will learn from the experience, as would I, or anybody else. Discus are extremely sensitive to their environment compared to most other fish, to a degree that most people cannot appreciate or understand. Doing what you propose, will get you closer to appreciating and understanding this, than not doing what you propose.