Pearling Issues

Hey all, I've got 125 litre tank with 110w light, external filtration, CO2 injection (propper and regulated to 30ppm) and live in South Bucks (so hard water). The only time I get pearling is when I change the water (1/2 tank as per EI) at which point it goes crazy for a couple of hours, then stops. What am I doing wrong??

After water changes its not pearling. Its the oxygen in the fresh water that gets trapped under the leaves rising.

If you're not pearling under that light with pressurised then something is not right.

By regulated I wonder if you mean you are using a Ph controller? If you are then I would stop using it to control the CO2 and instead just use it to monitor Ph levels. A Ph controller will turn the CO2 off at the given Ph level and then turn it on again when it rises etc which will provide inconsistent CO2 levels within the tank. If you must use it as a safety measure then set it to be 1.5ph below your tap water. That way it won't keep turning the CO2 off but will stop CO2 in the event of a Ph crash.

When you say it is 30ppm any reading wether from drop checker or Ph controller will not mean it is true. It means that in the area you have the DC or Ph probe that the ppm is 30ppm. elsewher in the tank there may be dead spots etc.

This is why we suggest 10x or more volume lph filtration. This enables a decent flow around the tank and then the CO2 and nutrients can be circulated fully around all areas of the tank.

The tank in my sig is a 125 Ltr tall with slow growing crupts, ferns and Anubias. I run 0.9WPG T5HO for 8 hours with pressurised CO2 and just under 10x volume flow (1100lph) lean dosing cia PMDD+PO4 and it pearls like crazy after 5 hours for thefinal 3 hours!!!!

A few questions:
Ph Controller linked to CO2?
lph of filter and brand/model
Tank dimensions
plantmass high / low (pictures are better)
Dosing regime
Photoperiod
Type of tubes T5HO / T5 / T8 etc.

AC

Sorry, I might have confused the issue slightly.... I meant it pearls directly after the 1/2 water change. I use the internal filter (Juwel Rio 125) and external Fluval 305 filter. No airation, some circulation but not at the surface.

All I can think is that there is something missing in the EI (but all bought from Aqua Essentials) that is provided in the tapwater. If this is the case how would I find out what is in my tapwater that I therefore need to add!?!?

The CO2 runs with the lights on and is around 2 bps (straight into the fluval external so it is all disolved). PH stays rock steady at 7pH and the gH is relatively high (I'm in a hard water area) which I pressume must affect the amount of CO2 in the water at 7pH.

Questions answered:
Ph Controller linked to CO2? No, CO2 on with lights, drop checker nice green / greeny-yellow.
lph of filter and brand/model Fluval 305 external (1000lph) and internal
Tank dimensions 80cm by 30x30?? Juwel Rio125
plantmass high / low (pictures are better) Pretty high, some things like tiger lotus grow really fast and have to be removed to let the otheres get some light at least once a week!
Dosing regime: as per EI on this forum.
Photoperiod - 2-8-2 at 55w - 110w - 55w - plant growth tubes
Type of tubes T5HO / T5 / T8 etc. - i think T5, they are the double tubes with connections only at one end.

Hope that helps!

You need to set your CO2 to come on about an hour before your lights, so that the CO2 content of the water is optimal for when your lights come on. You can also set it to switch off a few hours before lights out.

What Andy was saying about your water change is that small bubbles of O2 get trapped as you pour/pipe water into the tank, the water itself will also be more oxygenated so you will get bubbles trapped.

It may also be that your tap water is high in N, P or K (your EI ferts). If this is the case it might suggest you're not dosing enough ferts. Can you list what ammounts you're dosing?

I'll have to have a look tonight at the quantities of ferts because I worked them all out from the suggested figures on this site. I have also gently upped them. If i go much further with MgSO4 (it is the magnesium one but I can't remember what exactly it is) it goes cloudly for a couple of hours so I suspect I might be putting too much in - would this affect it? The fish seem ok.

The drop-checker in the morning is quite greeny-yellow rather than green and there is not a great deal of surface movement so I don't know if putting CO2 an hour early would be good for the fish.... what do you reckon?

It won't hurt the fish turning on the co2 an hour before the lights. Also, how close do you have the drop checker to the outlet of the co2. It should be on the opposite side of the tank, then you will get a better reading. If it is to close you are just measuring the amount that is close to where it is coming into the tank.

susankat said:

It should be on the opposite side of the tank, then you will get a better reading.

Click to expand...

I would move the DC every couple of days just to ensure there are no deadspots within the tank.

I'm not understanding why you need to add so much Mg into hard water? I wuld've though it would already be there. I have never had a problem with cloudy water when adding Mg but I don't dose to EI levels so I wouldn't know.

I turn my CO2 on 1 hour before lights on and off 3 hours before lights out. There is enough CO2 built up within this 6 hour period for the final 3 hours of light. I also run at 2bps on a 125Ltr but I have my Lily permanently 'sloshing' the surface about driving some away. This means that in the morning my DC is blue but when the lights come on at 4pm (1 hour after CO2) it is light green again.

You are confusing me about your Ph. Is it 7 from the tap? or is it 8 from the tap and 7 from the CO2 laden tank water?

AC

My pH is 7 in the tank, I haven't measured the water recently but can do! I did turn the CO2 up a bit last night as it was a little blue on the drop-checker and have corrected one of the light timers that had lost time. Photos attached.

More pics

Everything looks healthy and lush. To be honest, I wouldn't get too hung up on pearling As long as the plants are growing well and you have no algae then I'd say you're doing fine!

I would echo what Dev says. The crypt wendtii brown at the front will signal to you any problems.

Any defficiencies and it will loose it's shine and lighten in colour a little. Any CO2 problems and it will get BBA pretty quickly.

When I said my DC is light green by lights on I of course meant 2 hours after lights on as the change in the drop checker is a couple of hours behind the actual tank ppm.

AC

Tank is looking great

pearling is achieved when O2 production is greater than O2 absorbtion in the water. So adding more CO2 will mean the water will become oxygen saturated, after plants have got enough CO2, they will produce oxygen bubbles quicker than it dissolves in water.

While i am saying this, for some reason not everyone or everytank can achieve pearling!

Update: I turned the CO2 up to about 3 to 4 bubbles per second.... MASSIVE pearling, plants are shooting up too! I am tempted to leave it turned up to see the jungle that will be created pretty quickly and would assume all the little tiny bits of algae will die off too. Thanks guys!

Sorry to jump in, but what is the really bright lime green coloured plant, at the front center of the first picture?

Thanks

Schmill said:

Sorry to jump in, but what is the really bright lime green coloured plant, at the front center of the first picture?

Thanks

Click to expand...

looks like hemanthius micranthemoides to me.