# why dont my plants pearl ?



## Rich (14 Feb 2010)

I have a juwel rio180, fitted with 2*45w t5 lights and pressurised co2 injection.
With a KH of 11 and pH when injecting co2 of 7.1 i'm sure the co2 level is ok, no3 level is high (too many fish), phosphorous level is about 2ppm, am dosing K to about 20-30ppm and am adding something for the trace elements.
When i do a water change (40-50%) the plants start to pearl amost immediately but the next day nothing. any ideas what i'm missing ? obviously the new water is adding somthing i'm missing but the effect is very quick....far quicker than i'd imagine any fertilizers can be taken up by the plants.

thanks,
Rich


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## danmil3s (14 Feb 2010)

hi rich im no expert so some one might need to correct me. but i have the same thing after water changes i think its got some thing to do with he high levels of co2 or just gas in tap water. plants only pearl when the dissolved gas level in the tank water is maxed out. im not sure but i dont think the plants are pearling after a water change not 100% sure what that is i think if you want your plants to pearl you will need to add more light as very high light is needed 3 or 4 t5s covering tank front to back maybe


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## Rich (14 Feb 2010)

interesting. i was thinking that the lack of pearling was because there wasnt much photosynthesis going on but perhaps there is, its just that the fresh water has so much 'other' gas disolved in that the oxygen bubble from photosynthesis have no where to go. with older tank water there is spare capacity in the water to disolve the oxygen so you gont see it....i just need more plants to satureate the older tank water.
it makes sense, just never thought of it that way before.

thanks


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## Themuleous (14 Feb 2010)

'pearling' after a water change is called false pearling.  Dan is right about the reason for pearling, its when the O2 reaches max concentration.

Dont be fooled into thinking that no pearling = unhealthy plants, look at the plants, if they look healthy that probably are 

Sam


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## CeeJay (14 Feb 2010)

Hi Rich
I get excessive pearling after water change too   , I think most of us do if we're using water straight from the tap.
Your plants may be pearling, but if you have plenty of flow around the leaves it will not allow the 'bigger' bubbles to form, as the forming smaller bubbles get whisked away in the flow.
Anyway, a little experiment for you to try if it's bothering you that much.
After your lights have been on for a while, turn off your filters/pumps/powerheads or anything else you use to create flow. You will probably see your plants pearl within 5 minutes   .
I discovered this when, in my early days, I was doing a water change. 50% had been drained and I had the lights on but filters were off whilst doing a spot of maintenance   . Everything pearled like billyo. Most reassuring   .
I have the same tank as yourself, using the same lighting, and even my hairgrass is pearling   but it must be said my CO2 is maxed out  .
As previously stated though, our goal is healthy plants, and you can see that with your own eyes


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## Rich (15 Feb 2010)

thanks all.

i was naively assuming that no pearling meant that i was missing something. the plants are doing ok, there is a bit of an algae problem but thats completely my fault and as soon as i can rehome some oversized fish i can concentrate on my maintenance regime (the bala shark tries to jump out of the tank everytime the water level drops during a water change and forget trying any pruning/planting/aquascaping) i'm sure i can get on top of the algae.
Rich


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## George Farmer (15 Feb 2010)

Over the years I've observed that plants have a 'harder' time pearling in hard water.  

I'm not certain why; possibly CO2/nutrient uptake related.


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## Rich (15 Feb 2010)

well the water in my area is very hard so it may have some influence on it. i've got a RO unit so may try to dilute the hard water down a little at the next change and see what happens.


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## AdAndrews (15 Feb 2010)

My tap water is "moderately hard" apparently, ive managed pearling, but, at ridiculous co2 levels, when no livestock were present.


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