Has anyone used the Red Sea Plant Lab that measures Fe and CO2? I have a Red Sea CO2 DIY and I measured the CO2 tonight and its saying I have like 6ppm, which is nothing. I know I need like 25 to 35ppm. I know I have to make a new batch for the container, but does 6 ppm sound reasonable. It is not an extremely heavy planted tank, but it is close of being there. Just wondering how accurate this test kit really is. Thanks.

Hi schwark, Welcome to th forum. You ask some good questions but the answers will take some study.


These are not going to be accurate. For the most part CO2 is measured with a drop checker, see Drop Checkers/CO2 Indicators-Why and How for the CO2. As far as Iron, just add some version of EI dosing depending on you current setup.

For more detailed help you need to list your parameters ie, tank size, lighting, biomass, dosing schedule, type of CO2 being used and maintenance schedule.

I'm going to take all my measurements tonight when I get home from work.
I can tell you what I have for equipment.

20 Gallon Tank
65 Watt Coralife 6700k compact light
Marineland 200 bio filter (up to 40 gallons)
Red Sea CO2 cannister w/ venturi
Flourite Substrate

Plants:

Red Rubin Sword
2 Bunches of Moneywort
2 Bunches of Cabomba
1 large bunch of anacharis
Amazon Sword
Ruffle Sword
Marble Vals
Dwarf Tennellus - currently dying

Currently, I'm dosing with liquid ferts: Flourish, Excel, Kent Pro plant/freshwater, Flourish Trace and then nitrogen, and potassium every other day. I also have root tabs.

I dose Flourish and The Kent supplements 2 times a week and then potassium, nitrogen, and trace 3 times a week.

I bought some dry ferts from Aquarium fertilizer.com, but thats why I bought a test kit for iron, and phosphate, and KH/GH... currently I have a GH of 14, and a KH of 4 - which I believe is good. High gh is good from what I have read. I am almost positive my nitrite = 0, ammonia = 0, nitrates around 20 ppm, and ph around 7.8. It has been stable for months now. I change 30% of my water each week.

I have an african dwarf frog, and three smaller fish.

I do not know really where to start with the fertlizers... I bought KNO3, KS04, MgSO4, and CSM+B. This is what Alan said I should get since I am testing. He said possibly phosphate, but I decided not too since I have some fish, which he said I probably have enough phosphate. I will test to make sure. Should I add based on testing? I have read a lot about the EI method and other methods, but I am just not sure where I should really start. Hopefully I can get some direction. Thanks.

After testing, my nitrates were at 20ppm and my nitrite and ammonia was at zero. Ph was at 7.6.

Phosphate levels were at .1ppm which means I need more phosphate since levels should be at .5 to 1ppm. Am I correct on that?

Iron was around .1ppm and I'm not sure if I need more or not.

CO2... I need to get a drop checker, which I will look for a decent one for a good price.

Hopefully, with these results and the fertilizers I have, I could get directed well where to start. I thought about doing the EI routine, but that doesn't include the MgSO4... so just need a little help there. I'm still a newbie so be patient with my questions. Thanks for all the help!

This will be the hardest thing for you to do. Pack up your test kit and put them on a high shelf and do not touch Get some phosphate ordered right away and run the EI for three weeks and observe the tank.

I would start the 20-40 gal EI right away. Use KNO3, KH2PO4, and maybe the Barr GH booster. Your GH and KH are fine, the booster will fill in what is missing. Hold off on the MGSO4 until you are sure it is needed.

If you have been reading here then you know that Phosphates aren't harmful to fish and do not cause algae. Take our word for it and try. I'm not familiar with
your CO2 set up but the DC will come in handy.

Keep us informed of your progress and we will gladly help.

I just bought the test kits.... so that would be a waste of money. How about this... I will do the EI method, but I will still test just to use the kits, so I don't feel like I'm wasting money. I will order some phosphate, and how do I know if I need the MgSO4? If I am not testing for it, then how do you know you need it? Also, what about the CSM+B... I called the water department about the GH and it comes in high like I tested around 14. Would I need the GH booster then?

I will start the EI method tonight. The Red Sea CO2 is basically a liter of water with the yeast and sugar so basically a DIY CO2 system.

ALright, thanks.

I hate to sound mean but the test kits dont mean a thing. If you are using EI no matter if they say 2000ppm nitrates or 0, as long as your using EI everything is good

If you dose EI you do not need to know what the levels are, the plants will tell you better then any test kit around.



yes that is the definition of DIY. what is red sea about it? The diffuser?

One liter of diy is probably not going to cut it on a 20g. That would possibly be suitable for a 10g. You really need at least 3 or 4 liters of diy solution to get a good constant level of co2 on that sized tank. Anything less won't be worth your hassle. Also you want two bottles if possible, so you can keep them in constant rotation, that way it never gets super high or super low at any time.

Hi Schwark,


Let us also not forget that this is >3 wpg of light. This is a lot of light for such a small tank. This high light will drive high nutrient demand including c02. I would lower this at least by 50%.

If not, then you need to increase all your dosing including c02, to keep up with the demand.

DIY c02 may not cut it at these light levels........

Hope this helps.

Every 2 weeks should a new one be put in? Also, the only place I have to store a 3 or 4 liter bottle would be on the floor. Would that be ok?


Can I get a lower wattage bulb? Do they sell 45 watt bulbs... because I really do not have the money to buy a new light fixture. Otherwise I will just do more ferts and CO2.