The Cube

ceg4048

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Hi planter,
Normally, high KH has not been implicated as a causal factor in poor plant health although I'd have to imagine there is some upper limit at which growth would be affected. Unless it's absurdly high like something we'd see in Lake Malawi or someplace like that this shouldn't be a suspect.

Eco complete is as good a substrate as you'll find. The plants in the photo below were rooted in eco complete and kH 6-7 water which hardly ever varied so there must be some other factor, although from what I've read in some other posts there has been some batch problems with eco complete causing water cloudiness and possibly KH issues. BGA is normally a consequence of low nitrates or low flow and hair algae can sometimes be attributed to low CO2 or low flow. Depending on other variables, low pearling is typically associated with low CO2 relative to the amount of light so in my opinion it may be worthwhile concentrating the troubleshooting efforts in these areas.


Cheers,
 

ceg4048

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Yep, sure is, one of the pickiest of stems so ecocomplete and medium-high kH would have to be exonerated in this case.

Cheers,
 

planter

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ceg4048 said:
Hi planter,
Normally, high KH has not been implicated as a causal factor in poor plant health although I'd have to imagine there is some upper limit at which growth would be affected. Unless it's absurdly high like something we'd see in Lake Malawi or someplace like that this shouldn't be a suspect.

Eco complete is as good a substrate as you'll find. The plants in the photo below were rooted in eco complete and kH 6-7 water which hardly ever varied so there must be some other factor, although from what I've read in some other posts there has been some batch problems with eco complete causing water cloudiness and possibly KH issues. BGA is normally a consequence of low nitrates or low flow and hair algae can sometimes be attributed to low CO2 or low flow. Depending on other variables, low pearling is typically associated with low CO2 relative to the amount of light so in my opinion it may be worthwhile concentrating the troubleshooting efforts in these areas.

Cheers,
Thanks for the advice Ceg, My Kh was abnormally high (14!!!) I will look into the flow etc. Have just Ordered a drop checker so will use this as a reference for Co2 levels. Ive always had succes with the Co2 tables and have always found plant respond well And pearling is evident when Kh and Ph are aligned to achieve desired Co2 levels. I must admit to being a little bit confused as ive read in your posts that neither are reliable methods (drop checker/tables). The tables worked for me and im tempted to do what has worked in the past. Advice always welcomed.
 

beeky

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I think the general view is that the 4dKH drop checker method is a more reliable/accurate way to measure the CO2 than using tables. People have used the tables successfully but it has limitations. As long as you're aware of those limitations and don't treat the readings as gospel then it's OK IMO. Similarly with the drop checker really, as Clive has said in the past a nice green drop checker is not always a sure indication that there's adequate CO2 distribution throughout the whole aquarium.
 

ceg4048

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planter said:
Thanks for the advice Ceg, My Kh was abnormally high (14!!!) I will look into the flow etc. Have just Ordered a drop checker so will use this as a reference for Co2 levels. Ive always had succes with the Co2 tables and have always found plant respond well And pearling is evident when Kh and Ph are aligned to achieve desired Co2 levels. I must admit to being a little bit confused as ive read in your posts that neither are reliable methods (drop checker/tables). The tables worked for me and im tempted to do what has worked in the past. Advice always welcomed.
Hi planter,
KH 14 is pretty high and some time ago I lived on a farm with well water in a limestone geographical area. So the water was high in KH/GH. I had the opportunity to test this idea but I wanted to keep soft water fish so I never took advantage of the chance to use water as high as 14 KH. I don't have any data to prove it but I don't think that even this high of a KH can be attributed to poor health.

I know that it may sound a bit contradictory but the fact is that the drop checker and the tables, although crude, are the only cheap way we have of CO2 measurement, but that doesn't mean that they are accurate or even reliable, they are just better than having nothing at all. The tables work because of the small amount of carbonic acid that forms in the water when we add CO2. This carbonic acid drops the pH. The amount of carbonic acid that forms is directly related to the amount of dissolved CO2. The KH is a measure of the carbonates in the water and these carbonate ions react with any acids present which raises the ph. So the tables show a direct relationship between the amount of dissolved CO2->The amount of acid released into the water by is dissolution->and the amount of acid removed from the water by the carbonates present.

The table therefore is fairly logical because it links the three. The problem though is that if you then add an acid into the water that is not Carbonic acid, say nitric acid then you have more acid in the water than can be accounted for by CO2 alone. This corrupts the calculation from the table. In the tank there are all sorts of other acids being produced which do exactly that. So if you just use tank water readings for the table you will almost always read a higher CO2 content than is real because of the extra non-Carbonic acids. Depending on the tank and the way that it is maintained you may have a very high false reading to a moderately high false reading. Depending on the lighting, flow and other factors, like type of plant the false high reading may not matter because those plants in that particular tank under those particular condition may do OK with what is actually a lower CO2 content. In the dropchecker we isolate the water sample from the acids in the tank and we have a known kH so we stabilize some of the variables that cause corruption of the pH reading in the sample. The only change in ph of the dropchecker is that due to the CO2 that fizzes out from the tank water, across the little air gap in the checker and into our distilled water sample.

As beeky says, the next tank will have a completely different configuration in which the plants may not tolerate the the lower than measured CO2 content because the amount of CO2 being delivered across their membranes may effectively be much less as a result of the new configuration. So really you were fortunate before but perhaps less so with this setup. This is the problem with our hobby, there are so many variables and so many optical illusions. :arghh:

Perhaps you could try a test of upping the CO2 for three weeks or so and see if it makes a difference, then lowering it to pre-test levels and see if the plants suffer. Even lowering the light accomplishes effectively the same thing. There are lots of combinations. It may turn out that high KH is a contributing factor but in my experience the CO2 and nutrient content are much more influential variables.

Cheers,
 

planter

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got my drop checker and this seems to suggest Co2 levels are ok. Ive added a Tunze nano stream for extra circulation was a little bit worried about all the RO ive been adding so tested No3 ... 20 ppm (Am dosing TPN+) Will syphon off excess algae and see how it goes .... Too embarassed to post pic :oops:
 

ceg4048

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planter said:
got my drop checker and this seems to suggest Co2 levels are ok. Ive added a Tunze nano stream for extra circulation was a little bit worried about all the RO ive been adding so tested No3 ... 20 ppm (Am dosing TPN+) Will syphon off excess algae and see how it goes .... Too embarassed to post pic :oops:
Planter,
I guess I must be the only hobbyist in the entire Milky Way Galaxy who doesn't think his CO2 is OK. :rolleyes: The thing is that BBA is a CO2 issue beyond a shadow of a doubt. I'm exaggerating a little bit but I reckon that it can't be due to high KH otherwise Lakes Malawi and Tanganyika might be completely choked with BBA. If you ask for a show of hands for anyone who has had BBA in low KH water you'll see too many hands to count, so it can't be a KH issue because it occurs with equal regularity at any KH. You've got 3wpg on this tank which is serious business and is unforgiving.

BBA can only be induced singly or via combination of the following factors:
1) Unstable CO2 - perhaps turning on CO2 an hour or two before lights ON.
2) Low CO2 - inject at a higher rate.
3) Poor flow - A deep cube has difficulty getting nutrients/CO2 to the bottom. Consider using a spray bar mounted on the back just to experiment.
4) High lighting. Starting up a tank with max lighting can be difficult due to low plant biomass and low sediment bacteria. The sediment bacteria are supported by the plants and by any organic matter in the sediment. More CO2 means more oxygenation of the sediment and a better ability for the sediment to convert NH4 to NO3. Consider shutting down of 25%-50% of your lighting to lower the CO2 demand.

The Tunze might solve the problem of flow but any of the other areas listed above are something to consider and will produce better mileage than chasing KH in my opinion. If there are no fish in the tank then you can really go to town and open up the needle valve. :D

Cheers,
 

planter

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Im hearing you Ceg,

The drop checker was installed as the best available reference. Based on your advice im up to 4-5 BPS (more than I can count anyway). I think the Tunze will offer better Co2 distribution ... I can only pressume the lilly pipe set im using is slowing the oputput of the filter somewhat, Wasnt until I swithched the Tunze on That I realised just how still the water was. Co2 is currently on 1 hour before lights on Im going to adjust this to 2 hours before.

Thanks for your help
 

john starkey

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Hi Planter, i have nine bags of eco-complete in my setup and my kh and gh were high for the first two months then it settled down to its more normal level , regards john.
 

planter

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Interstingly ive just set up another tank. I used Red Sea Flora base substrate and filled the tank with 75% RO 25% tap as I always do. Kh 4, ph 6.5, drop checker (4dkh solution) lime green, plants pearling nicely, Everything happening exactly as I would expect. Using these readings on a Co2 table I have a Co2 level of almost 38ppm ! High I know but no fish to worry about at the mo. This I pressume would explain the plants heavy pearling.

Complete contrast to whats been happening in 'The Cube'.
Kh 9, Ph 7.5 drop checker light green, No pearling. Co2 tables indicates Co2 level 8.5ppm.
The Co2 is going into this tank at 4 - 5 BPS.

both tanks are of a similar size and have the same amount of light over them.

I am simply making my own observations here but my conclusion is that the High Kh value (buffer capacity) of 'the Cube' means im having to use lots of gas to try and reduce pH which is proving difficult. Is it possible that the more acidic I make my aquarium water the more carbonates are being released from the substrate ???

Disregarding tables and drop checkers completeley .... tank with low kh is pearling niceley tank with high kh is not (it also has some serious algae issues). I agree that there is obviousy a lack of Co2 but that is not because it is not being pumped in fast enough.

I often read in peoples journals that their Co2 level is 20-30ppm , how are people establishing these facts if they are not using tables or calculators?.
 

planter

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aaronnorth said:
Can you post a pic, there must have been quite a lot of growth :D
yeah there has been a lot of growth ! Algae growth :(

thecube.jpg



Heres a sneaky peek at the new tank -

rockscape.jpg
 

LondonDragon

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Its looking great planter, I am sure you can overcome the algea :)
The new hardscape looks brilliant, can't wait to see it fully grow :)

Keep us posted :)
 

ceg4048

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Hi Planter,
I've studied your analysis and something doesn't compute. If I had to guess I would say that you are still using the pH reading of the tank water into the equation when calculating CO2. For example you advise that the dropchecker in the cube is green yet that the pH is 7.5, which is inconsistent. If the pH of the dropchecker's water were 7.5 it would be aqua blue, not green. A green dropchecker would yield a pH value of it's sample water at or below 7.0, so something sounds fishy.

Another thing to note is that the drop checker is currently mounted at the top right hand extremity of the tank where there are no plants, and where CO2 is at it's highest since it rises to escape the tank. A good troubleshooting procedure would be to mount the checker down at the lower left just behind those frizzy plants behind the wood, or even at the lower left front corner. See how long it takes to get the lime green color. Another thing you might try is to mount your diffuser in different location, like behind the frizzy plants for example. If your bubble rate is high and you still have problems then this points to a flow/distribution issue. The cube is tall relative to it's other dimensions so it's very difficult to get CO2 to penetrate to the lower reaches of the tank. Try moving the outflow pipe around.

KH has no bearing whatsoever in the waters ability to dissolve CO2. With high alkalinity, the only thing that happens as you've noted is that the pH will not fall as much as in a low KH tank but this does not affect CO2. The only way to affect the quantity of CO2 in the water is to add or subtract CO2, regardless of the water's KH. However, if the CO2 is poorly distributed then the effect is the same as if less CO2 were being added to the tank. The issue of KH and it's effect on the plants and algae is a very seductive optical illusion and this apparent correlation does not imply causality. There are plenty of KH 9 tanks that are not suffering this problem. If your nutrients are correct, lighting not excessive, and if your injection rate adequate then the only thing left is distribution.

When most people say they have 20-30ppm CO2 it is because a green dropchecker means the water sample in the checker is at or around 6.6 pH and the KH of the dropchecker water is 4 KH. If you were to plug these numbers into the table you would see that the result is more or less 30ppm. Therefore 30ppm CO2 in the dropchecker water sample must necessarily mean that the tank water also has 30ppm as there is equilibrium of carbonic acid between the two waters. Green dropcheckers therefore become synonymous with 20-30ppm CO2 assuming 4 dKH water is used.

If you were to add sodium bicarbonate to the good tank you would see a rise in alkalinity but you would see no change in the dropchecker color. You would not suddenly see an algae attack either, just a KH rise, that's all.

Another note about KH and plants: In low tech tanks, where CO2 is not being injected high KH is a good thing. This is because KH is a direct measurement of the water's content of carbonate (CO3) and bicarbonate (HCO3) ions. In the absence of CO2 injection many plants are able to strip these two ions of their carbon (C) and to use it in lieu of CO2 gas, thus actually lowering the KH and thus pH of the water. So there is no way high KH can be implicated in poor plant health.

Having said all that there are a handful of plants which tolerate high KH/GH but which do much better in low KH/GH water. Tonina comes to mind, but you have none of these known low KH/GH plants.

Hope this makes sense. :D

Cheers,


Edit: Ooh, by the way, that second tank is totally awesome. :D
 

planter

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Prior to setting up my 3 tanks again (and having scaped numerous reasonbly successful tanks) I really thought I had the plant growth sussed and was determined to concentrate more on the hard scaping. Seems 'the cube' has given me a bit of a wake up call and Im learning not to disregard the basics of running a planted tank.

Guess this is what makes the hobby sooo enjoyable ' the highs and the lows '

Appreciate everyones help at UKAPS!
 

planter

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Just back from 2 day trip to Germany but having Introduced some SAE and Amano Shrimps before I left The Algae has pretty much disappeared now! The new scape is growing well and I seem to be able to maintain Co2 level much easier in this tank with a lower KH. Im not pleased with the scaping of the cube and will be making adjustments as soon as I get hold of some hardscape materials.
 

planter

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Been giving the Cube a little more attention recently and it seems to be paying off. Stil not happy with the general scape (despite moving the wood) but the plants seem to be doing a little better. The rotalas have had a good trim and with regular dosing TPN+ the algae is almost history. Still no real evidence of pearling (4/5 BPS!) but have just carried out a BIG water change in an effort to win my on going battle with high KH. I know its said that KH isnt an issue but Im going through gas at an alarming rate to try and keep the Ph down.

Oh I also removed the lilly pipe set (now broken) as It kept blocking so im back to my ol eheim bits. This has meant increased flow from the external so ive removed the Tunze 'nano' stream (it was a tad feirce)
One more little change Ive added purigen to the cannister filter which seems to have sorted out the bog wood tanin.


heres a recent pic (the tanks not cloudy i was messing with the camera settings) -

DSC04172sdf.jpg
 

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