260 L planted tank, minimum maintenance

[_Maq_]

I'd be interested to know what we can do to maximise dissolved oxygen

I do not possess dissolved oxygen meter, unfortunately. All I know/guess is based on literature and personal observations.
In general, DO is a very volatile variable. The most important consumers of oxygen are microbes, primarily heterotrophs. Therefore we may say that dead organic matter (both particulate and dissolved) is the scavenger of oxygen.
To increase oxygen content, we should restrict feeding fish. Even if you make a one-day break in fish feeding you can help the situation significantly. In long-term perspective, modest stocking by small fishes helps the oxygen balance.
Mineral loading (fertilizers) increase oxygen demand indirectly, too. We say that majority of our microbes are heterotrophs, but that means no more that they consume reduced, i.e. organic carbon. As for other elements, they definitely don't refuse them if served in mineral form. Now, it is quite a common situation that a lot of organic matter is a source of reduced carbon but poor in other nutrients. Such an organic matter is not very attractive for microbes - they can't live on sole carbon. But if you add other nutrients into the habitat with fertilizers, they can saturate their needs for other nutrients from these mineral compounds and take reduced carbon from dead organic matter which was - until now - unattractive. In such a way, we can boost microbial activity, proliferation, and oxygen consumption.

What are the sources of oxygen? I believe plants are generally more important than gas exchange at the water surface. Plants (and algae) can make water oversaturated with oxygen (more than 100 per cent of oxygen dissolved in standard conditions). Aeration can increase gas exchange but, as a rule, cannot oversaturate.
The problem with plants (and algae) is that during night they turn into net consumers of oxygen. In the dark period, therefore, gas exchange on the surface is the only source of oxygen.

I'm still a bit puzzled as to what caused the oxygen crisis).

A dead fish, mollusc(s), shrimps may increase oxygen consumption dramatically. Temperature rise can increase microbial activity while oxygen solubility decreases. Various situations lead to die-offs of plants, algae, microbes. This is followed by increased demand for oxygen.

I would like to attempt lowering the ph without using chemicals, ie roots, peat moss,

Do you think roots, peat moss, herbs etc. can change pH by anything else but chemicals?
The disadvantage of natural materials is that they are never pure, so apart from desired chemicals they release some undesired or unknown ones at the same time. Par example, organic chemicals which increase oxygen demand. That is not to say that natural herbs etc. are always undesired.
On the other hand, pure (laboratory) chemicals have no unintended effects. If you decrease pH by sulfuric acid, you know that you add sulfates and turn bicarbonates into free carbon dioxide, period.

 

[fredi]

Absolutely, although not strictly necessary, for some it’s part of the hobby. I must admit I enjoyed using multiple test kits for a while. Now I just do ammonia, nitrite and nitrate at the beginning of setup to help gauge when the tank is ready to introduce fish and other critters.

I should have added, that I only test on new setups nowadays
I “know” what the NO3 in the Tropheus tanks are as I keep to water change routines, and use NO3 removing resin on water used in water changes, years ago I found that I was having trouble getting the nitrates down to “reasonable” levels in the Tropheus tanks, that was until I found that the tapwater was 40ppm😩
Once the filters (and bacteria in tank) are “ up to speed”, I see little point in continuing to test for ammonia and nitrite, sensible maintenance, and gradual critter additions will keep bacteria levels/activity appropriate for the job in hand

 

[dw1305]

Hi all,

I'd be interested to know what we can do to maximise dissolved oxygen, beyond lots of healthy / fast plant growth and good surface movement.

They would definitely be the main factors.

I'll try and re-home the article I wrote about 12 years ago <"Filtration and flow for fish only tank?">, it could do with an update, but I still agree with the basic tenet of what I wrote <"Oxygen levels required">.

To increase oxygen content, we should restrict feeding fish. Even if you make a one-day break in fish feeding you can help the situation significantly. In long-term perspective, modest stocking by small fishes helps the oxygen balance.
Mineral loading (fertilizers) increase oxygen demand indirectly, too. We say that majority of our microbes are heterotrophs, but that means no more that they consume reduced, i.e. organic carbon. As for other elements, they definitely don't refuse them if served in mineral form. Now, it is quite a common situation that a lot of organic matter is a source of reduced carbon but poor in other nutrients. Such an organic matter is not very attractive for microbes - they can't live on sole carbon. But if you add other nutrients into the habitat with fertilizers, they can saturate their needs for other nutrients from these mineral compounds and take reduced carbon from dead organic matter which was - until now - unattractive. In such a way, we can boost microbial activity, proliferation, and oxygen consumption ........... A dead fish, mollusc(s), shrimps may increase oxygen consumption dramatically. Temperature rise can increase microbial activity while oxygen solubility decreases. Various situations lead to die-offs of plants, algae, microbes. This is followed by increased demand for oxygen.

The "risk management" side in some ways relates to the concept of <"Biochemical Oxygen Demand (BOD)">, again something that isn't easy to measure.

I've no intention of going down the route of trying to measure it, but given my stock tank did once briefly trigger classic 'fish gasping at surface' behaviour after being apparently fine for a year or so ..

Possibly <"chloramine in the water supply">, if you use tap water? The other problem may just be fish growth , although you can mitigate for this <"6.2. Biofiltration in an Aquarium">, even with <"insane stocking rates">.

(I was keeping Tropheus, ignore anyone who tells you that NO3 levels don’t matter to fish

Tropheus would be particularly problematic, you have the <"Mbuna scenario">, and you also have a fish from Lake Tanganyika, <"an inland "ocean"> with incredibly stable parameters. Add in them being vegetarian, and that means you need a spatial separation between fish and vegetation. I think you could do this with a floating plant.

cheers Darrel

 

[fredi]

Hi all,

They would definitely be the main factors.

I'll try and re-home the article I wrote about 12 years ago <"Filtration and flow for fish only tank?">, it could do with an update, but I still agree with the basic tenet of what I wrote <"https://www.ukaps.org/forum/threads/oxygen-levels-required.43073/">.

The "risk management" side in some ways relates to the concept of <"Biochemical Oxygen Demand (BOD)">, again something that isn't easy to measure.

Possibly <"chloramine in the water supply">, if you use tap water? The other problem may just be fish growth , although you can mitigate for this <"6.2. Biofiltration in an Aquarium">, even with <"insane stocking rates">.

Tropheus would be particularly problematic, you have the <"Mbuna scenario">, and you also have a fish from Lake Tanganyika, <"an inland "ocean"> with incredibly stable parameters. Add in them being vegetarian, and that means you need a spatial separation between fish and vegetation. I think you could do this with a floating plant.

cheers Darrel

Thanks 👍
Yes I have some plants, cryptocoryne can survive , some even do well, they are damaged, but not totally devoured, i do have a floating plant which survives, i have the name somewhere, i will post it later
Duckweed is pretty much instantly devoured, like sweets to children

 

[hwscot]

Possibly <"chloramine in the water supply">, if you use tap water? The other problem may just be fish growth , although you can mitigate for this <"6.2. Biofiltration in an Aquarium">, even with <"insane stocking rates">.

Well, it's a livebearer stock tank, with an inevitable supply of youngsters, and occasional deaths of older fish, so I could see that perhaps gradual growth of the stocking level with maybe a couple of deaths (if they happen to be at the back of the tank behind lush plant growth, it's easy to miss them) could maybe take things across a threshold.
But it was so sudden, literally overnight, that it would imply there is a clear threshold, and if so, it would be nice to have a simple way of recognising when it's approaching.
I dip-test occasionally just to check that nitrates aren't creeping high, but I mainly just look at plant growth and fish behaviour. There's been no recurrence. There was one double-sponge filter in previously, plus one mini Pat. I've added the Aquael Turbo 500 (which basically just slightly beefed up Pat) and have had a play with a DIY moving bed filter; the Pat and the Turbo 500 now both have venturis - I didn't bother before .. I'm pretty confident the tank has adequate filtration: I can never discern nitrites, and nitrates are always very low.
I doubt it would be chloramine, which we do have in the tap water, but I always treat before water changes, which are modest .. about 10% - I work to a rigorous schedule of 'I guess it must be a couple of weeks or so since I did one',
FWIW, if you're a gardener and you happen to buy Miracle Gro slow-release in those clear plastic tub / bottle thingies, and if you have a spare sponge filter around and some mini K1, you have the makings of an easy peasy cheap moving bed filter. It ain't pretty but it works, and at least the plastic cap is green. You may find it will perform .. [temptation resisted]
About to make a cup of tea and read that biofiltration piece.

 

[Outzen]

Did some measuring today - still in dark start mode
Drop tests:

• No2 Pro JBL Aquatest - Nitrite: < 0,01
• NH4 Pro JBL Aquatest - Ammonium: < 0,05
• GH Tetra Test: 13 dh
• KH Tetra Test: 15 dh

 

[Outzen]

• GH Tetra Test: 13 dh = 232.7 ppm
• KH Tetra Test: 15 dh = 268.5 ppm

ie - im in the "very hard" zone

 

[Outzen]

This question will probably generate a lot of head shaking .... but cant help asking anyway
One way of lowering the KH could be to add 1/3 of destilled water - ie 2/3 of tap water and 1/3 destilled water (have found one brand that claims a ph of 7.0). If I keep this ration when doing water changes, could that work?
In theory, would that move my numbers down (and not create other problems)?

 

[LMuhlen]

This question will probably generate a lot of head shaking .... but can help asking anyway
One way of lowering the KH could be to add 1/3 of destilled water - ie 2/3 of tap water and 1/3 destilled water (have found one supplier with claims a ph of 7.0). If I keep this ration when doing water changes, could that work?
In theory, would that move my numbers down 1/3 (and not create other problems)?

That is actually a very common practice for those with very hard tap water. Yes, it should work. You can also use rain water, with due care. Given how hard your water is, you could even use a much more aggressive ratio. I don't know about the cost for this, but I'd try at least 50%.

 

[_Maq_]

ie - im in the "very hard" zone

I'm not injecting CO2 but in my country, those who are say that with such high alkalinity even CO2 injection does not make much sense. In theory, they seem to be right. Yet others in this forum maintain that CO2 injected does not turn to bicarbonates. I'd like to understand better this question.
Anyway, liquid rock always presents inconvenient limitations both for plants and fish. You either accept it, or you acquire reverse osmosis. My tap water is also pretty hard, and believe me, I've tried many methods to soften it. Reverse osmosis is by far the most comfortable and effective. Now, I can't imagine doing this hobby without RO.

 

[Outzen]

Anyway, liquid rock always presents inconvenient limitations both for plants and fish. You either accept it, or you acquire reverse osmosis. My tap water is also pretty hard, and believe me, I've tried many methods to soften it. Reverse osmosis is by far the most comfortable and effective. Now, I can't imagine doing this hobby without RO.

I'll probably end of with some kind of RO/DI system, but for now I have orderet 14 x 10 Lit cans of destilled water, which I will mix with my current water in a 50/50 ratio (ref advice from LMuhlen - thks). Hoping this can lower the GH/KH considerably and that I will be able to maintain PH/GH stability by using the same ratio when changing water. I paid around 110 usd (770 dkr) for that portion, and If I do a 20 lit water change weekly it will cost me around 37 usd/month - so its not cheap. One way to go from here is to facilitate for a balanced eco system where I can minimize water changes ... however most people in here has adviced against cutting down on water changing, so untill i get some more insights on how my environment is behaving, this will just remain a wishfull thought

 

[Wookii]

Hoping this can lower the GH/KH considerably

It will lower it by exactly half - which will make no meaningful difference as you will still have relatively highly alkaline water at approx. 6dKH and a resulting high pH of around 8pH.

If I do a 20 lit water change weekly it will cost me around 37 usd/month

No where near enough water being changed there - increase that to 25%, so 52 litres weekly, so 96USD/monthly!

Insane cost - the $110 upfront and a couple of additional months of DI water would get you a decent quality RO unit!

 

[_Maq_]

I'll probably end of with some kind of RO/DI system

Have no fear of RO technology. I'm a very stupid guy when it comes to practical matters, after all, I'm a lawyer by profession. And still, I've got acquainted with RO/DI quite easily, I even dare to customize various pre-filters to optimize the performance. It's really quite simple, user friendly. The only issue is to accommodate it neatly within your bathroom and make regular WC convenient.
In not so many years, I think this technology will become just as common as a microwave, a norm in a modern household. Tea prepared with RODI water is soooo much better!

 

[Outzen]

In not so many years, I think this technology will become just as common as a microwave, a norm in a modern household. Tea prepared with RODI water is soooo much better!

And this would be a possible selling point to "she who must be obeyed" - remotely possible that is!

It will lower it by exactly half - which will make no meaningful difference as you will still have relatively highly alkaline water at approx. 6dKH and a resulting high pH of around 8pH.

Very disappointing if that will be the case - the vendor said a ph of 7 for the destilled water ... think my tap water is around 8.5 now, and was hoping that a 50/50 ratio combined with plants & roots could bring the ph down to 7.5 -7.7 ... which to me would be great. But ofcause - if I need to use dkr 1000/month for destilled water, I will need to change my strategy anyway.

 

[dw1305]

Hi all,

the vendor said a ph of 7 for the destilled water ...

It is a bit of a strange one, simultaneously it is both:

• true and
• untrue and
• totally irrelevant.

Unfortunately pH always needs a bit of interpretation. Have a look at <"Consistency Deficiency">.

cheers Darrel

 

[Outzen]

It is a bit of a strange one, simultaneously it is both true and untrue and also totally irrelevant.
Unfortunately pH always needs a bit of interpretation. Have a look at <"Consistency Deficiency">.

Thks - red the <"Consistency Deficiency"> and understood very little, but what I do understand (i think) is that when trying to improve my tap water quality (improve = making it more acceptable to plants and fish) by mixing it with destilled water - I cannot be sure that it will actually result in softer water.
One of my main motivations for returning to the aquarium hobby was to set up a beautiful planted tank with my favorite fish - Rams.
AFAIK rams prefer soft water - I have very hard water. So - if you were in my shoes - and not prepared to give up keeping rams, what would you do?

 

[_Maq_]

the vendor said a ph of 7 for the destilled water

"Ideal" distilled water indeed features pH = 7. In reality, you can hardly avoid atmospheric gasses dissolving in water, and one of them - carbon dioxide - pushes pH of "real" distilled water somewhere around 5.5.
Yet that's not the end of story, unfortunately. pH is a logarithmic number, so it does not work like 8 * x + 6 * x = 7 * 2x.
To make any reasonable assessment of your situation, you should know in the first place:
(1) what is your tap water like - as close as possible to full analysis, and then the more difficult part
(2) what would your ideal water be like - key parameters like pH, calcium/magnesium content (hardness). The latter depends on what you're about to do in your tank, because we always must meet the demands of its inhabitants - fishes, invertebrates, plants.
That said, it is still possible to make a nice and healthy tank with "liquid rock". Albeit with restrictions. This is UKAPS, a forum dedicated to plants, but nobody here insists that an aquarium devoid of "rarities" is any less worthy as long as it's kept in good order. In fact, the reverse situation is much more common, and it's a sad spectacle.

 

[dw1305]

Hi all,

....... by mixing it with destilled water - I cannot be sure that it will actually result in softer water.

Sort of, it makes the water softer and less alkaline, but it doesn't reduce pH.

...... AFAIK rams prefer soft water - I have very hard water. So - if you were in my shoes - and not prepared to give up keeping rams, what would you do?

A favourite of mine as well, personally <"I'd use rain water">.

Cheers Darrel

 

[Outzen]

Sort of, it makes the water softer and less alkaline, but it doesn't reduce pH.

Have come across many resouces via google that claims that using RO setups is one way to reduce ph, but as you and others have explained there are other factorers in play. But ... wouldnt it be more fair to write it dosnt necessarily reduce the ph?

I'm not injecting CO2 but in my country, those who are say that with such high alkalinity even CO2 injection does not make much sense. In theory, they seem to be right. Yet others in this forum maintain that CO2 injected does not turn to bicarbonates. I'd like to understand better this question.

Also, many claim that Co2 would also help lowering ph - this e.g. from BYA - where it is suggested that Co2 injection can help keep ph levels stable, and even lower PH.

With the KH levels I have now, the buffering capacity in my tank would probably work against the ph lowering effect of Co2 - so logically, lowering the KH with distilled water, and combining this with Co2 injection could be a relevant approach if I want to soften the water and get the ph level down to "more acceptable levels". Ofcause not sure if I eventually find out that "CO2 injection does not make much sense", but think Co2 injection could be a relevant option for me to try.

Im still keen on going with RO water - ie. 50/50 ratio - after all, I have already bought 140 lit - which I in theory could return, but in practice want to try out (Alea iacta est) . Im thinking that in the long run - if it works, I will commit to a RODI system or even rain water if I can build up a practical system for that. Also thinking that I would want to try out supplementing with Co2 injection, if the mixing of tap & RO water - together with roots and plants, dosnt seem to bring down the ph value significantly.

Driftwood and peat moss has also been mentioned as ph lowering. I already have driftwood in the tank - and it dosnt seem to have had any effect on the ph reading - but then again, 1 week may be to short a time frame.

So will continue with my dark start. Will get the cans this afternoon and make the water change tomorrow. Then start planting on wedensday next week.
Then wait and monitor how things work out before adding fish.

 

[dw1305]

Hi all,

Have come across many resouces via google that claims that using RO setups is one way to reduce ph

It is, but the problem is that pH isn't a linear scale, it is both a log10 value and a ratio. Have a look at <"pH curves (titration curves)">.

If you have tap water that is 8 dKH it will have a ph value of ~pH8, via the <"CO2 ~ HCO3- ~ pH equilibrium"> - <"CO2 and pH: Understanding Henry's Law">.

If you dilute that tap water 50 : 50 with RO water (dKH = 0) you will half the dKH. Your 50 : 50 mix is now 4 dKH, but still ~pH 8.

If you then diluted the 50 : 50 mix with 50% RO, you now have 25% : 75% tap : RO and 2 dKH. When you get to ~2dKH pH will become unstable, and may start to fall as you add acids (proton (H+) donors) from humic compounds etc <"All the leaves are brown… — Seriously Fish">.

If I <"was keeping Rams (Mikrogeophagus ramirezi)?"> I'd want to be at 2dKH or lower, with some humic compounds.

By adding RO we've reduced the amount of carbonate <"buffering"> and the <"acid neutralising capacity"> (the amount of proton (H+) acceptors) of the water. Have a look at <"Some handy facts about water">.

Also, many claim that Co2 would also help lowering ph - this e.g. from BYA - where it is suggested that Co2 injection can help keep ph levels stable, and even lower PH. ..... With the KH levels I have now, the buffering capacity in my tank would probably work against the ph lowering effect of Co2 - so logically, lowering the KH with distilled water, and combining this with Co2 injection could be a relevant approach if I want to soften the water and get the ph level down to "more acceptable levels". Ofcause not sure if I eventually find out that "CO2 injection does not make much sense", but think Co2 injection could be a relevant option for me to try.

Back to buffering and Henry's law, have a look at <"Is CO2 really worth it??">. Basically adding CO2 increases the amount of <"Total Inorganic Carbon (TIC) in the water"> and lowers pH, but it isn't the same as having soft water.

cheers Darrel