Tapwater very high in PO4

[raceface]

Hi,

I recently made a a new setup, but my plant doesn't want to start. major problem occured when I made some test using the tap water , I realized it is very high in Po4( about 3 - 4 ppm ) and very low in No3 ( 0,2 - o,3 ) , does that influence plant growth.?
My tank is 300 L , I use for now only 2 lights 54Wx 2 t5ho ,have lots of fast growing plants, my co2 is at max speed, eheim 2028 external filter, internal filter 1500L /h,.
At first I started to dose few amounts of macros also micros, but when I realized how much macro I had in tap water it was no sens for half dosing the macros. so I insted added plus 20 ppm nitrates to kind of equalate the diffrenece.
Plants seems to be blocked , they did not grow an inch in weeks , instead algaes are getting all over , especialy green fuzz on the hair grass.
Any ideas what could I do ?

[Tug]

Hi raceface,
First a few questions to fill in the gaps.

• How recently did you setup your tank?
• How are you diffusing CO2 into the water?
• What plants are you worried about?
• How far from the substrate are your lights and how long are they running?
• Do you have a water quality report you could share?
• Are you adding any Ca and/or Mg and how much of what trace are you adding?

EI doses are designed to insure no nutrients are limited. As long as you have enough for the plants to grow, you can focus on your lighting and improving the levels of CO2. That is where you will need to make adjustments. Making sure to keep O2 levels high for critters.

20ppm NO3/week is at the low end of EI dosing. It might be fine until your plants are growing in, but it is on the low side. PO4 might seam high but it is also on the low end of EI.

Try reducing your light to only one t5ho until you are confident your CO2 is reaching at least, 30ppm. This should help reduce the algae. Extra water changes, 2 x week.

I would suggest adding more current with a powerhead or two. 1500L is almost not enough. I like the water in the aquarium to turn over at least 8-11 times per hour. This also seams to help distribute CO2, O2 and nutrients.

[raceface]

Hi Tug,

here are some answers for you:

- the tank is about 4 weeks old
- the co2 is dissolved by an external diy reactor made of water filter and bioballs , I add 5 bps.
- none of my plants are growing well: ludwigias , hz , sessiflora , disiplis. I use this plants temporarly , I want to make this setup stable with specis like Limnophila aromatica, Ludwigia cuba, blyxa japonica , and parvula as the hairgrass
- my lights are right above the water surface - 5 -6 cm , they are running 8 hours a day with no break.
- water quality does not say much about po4 , only nh4 0.1, ph 7.7, no2 0.005, no3 1.5, and thta's it.
- i do not add any mg nor ca , but I doble dose the trace like 30 ml each other day.

I am affraid reducing the light to only one will make the plants suffer , the tank has 50 cm dept , and for the water changes ...every wc will add the same amout of po4 ...

[Tug]

I'm about at the end of my usefulness. I'm sure someone with more experience then myself will continue to help.

CO2 and water changes:
The water change suggestion was more about adding CO2. I believe Tom ran a test on tap water and found CO2 levels around 30ppm or higher.

CO2 is difficult to measure. How are you determining you have enough, other then counting bubbles?
You might want to try checking your pH for a ruff guide.

PO4:
I hate to say your test isn't accurate, but… Dose the full EI amounts for your tank to rule out nutrient deficiencies like PO4. Keep at your weekly water changes - two or three a week for four more weeks would be even better. Read this; http://www.barrreport.com/showthread...ter-Phosphorus

The Light:
As I understand it, one T5HO would be enough light, if CO2 is available, for any of the plants you mentioned. Your lighting isn't crazy bright with the two bulbs, but it is on the edge. Raising them an additional 3 inches (8 cm) would help improve things. At least you would be in the mid-high range. Barring that, I would try just the one bulb.

Ca & Mg:
Most products that provide micro-nutrients (trace) do not contain Ca and have little, if any, Mg. Avoid Ca and Mg deficiency by adding a GH booster of your choice. Both Ca and Mg are extremely important and adding them will insure the plants have enough. A GH booster also adds potassium - all good.

Another option might be to add MgSO4.7H2O (epsom salt) and CaSO4.1/2H2O (Plaster of Paris). Tap water generally has sufficient Ca levels but Mg levels are often too low for growing plants. So, until you know what is in your tap water, adding three teaspoons/week (15 grams) of epsom salt will boost your Mg levels by about 5ppm and 15 grams (about 5 teaspoons) of CaSO4.1/2H2O/week will provide 15ppm Ca. This will raise the general hardness by about 3 dGH.

For more accurate dosing calculations try Wet's calc. at; http://calc.petalphile.com/

[raceface]

CO2 is difficult to measure. How are you determining you have enough, other then counting bubbles?


I simply watch the fishes and shrimps, poor fishes almost started to gasp at the surface so i had to reduce the co2 speed a bit .

[ShadowMac]

fish behavior and plant growth are usually the most reliable measures for adequate CO2.

bubble counting is not a good way to figure out your CO2 rates because it may be different from tank to tank, regulator to regulator, bubble counter to bubble counter. In short everyone's equipment may be different, so having the same bubble rate does not mean you a have the same ppm's of CO2 within your tank. Diffusion methods and flow vary from tank to tank as well.

I use a drop checker to get in the ball park and fine tune by using fish and plants as an indicator.

[Tug]

1. All I can say is, if your not dosing PO4 or a GH booster (Ca, Mg and K) and your plants aren't growing, what do you have to lose by adding them? EI will not cause algae and (assuming your test is correct) adding another 3ppm/week is not going to either. Start adding 1.3ppm PO4 3xweek, give your plants some time, then you can adjust downwards until you see deficiencies again if you feel compelled to . Keep adding KNO3, about 7.6ppm 3xweek and 1 teaspoon of GH booster with your water change.
   
2. Your filter is underpowered IME and might have more to do with your fish stress then the CO2 your adding.
   
3. Reduce your light to a more exceptable range.
   http://www.barrreport.com/showthread...ent-myth/page2

[raceface]

my only concern about using only one light is , how are plants gonna pearl with one 54 w light?
If they do not pearl how do I expect any growth?

[ShadowMac]

no pearling does not mean no growth, only slower growth...and more likely more stable and most importantly sustainable growth.

I have chased the pearling monster a lot and found that the tanks that pearl less grow better and are more tolerant to periods of neglect. They are also more forgiving to mistakes...and since I can never avoid tinkering for too long I am bound to mess something up somewhere...

Pearling is overrated.

[Tug]

Mostly your right, you will not often see or hear of pearling at, 0.9wpg or 1.4wpg. Although I keep trying. We are lowering the bar between PAR and demand. Less light is more forgiving. And with the added CO2 availability the plants do grow.

My guess about photosynthesis is that it increases dissolved oxygen to a saturation point, if CO2 levels can be reached, without fish dropping out, meeting the nutritional needs from driving hard and fast - then you see pearling. But there are probably other ways to achieve pearling. The amount of dissolved oxygen might drop under less light (I don't really know) but no likely consequences other then less algae that I can explain. Still, you might reduce your CO2 and then bring it up if the fish respond well to the idea - keep fish first.