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· Registered
6 Posts
Discussion Starter · #1 ·
Hello, I am in need of help. :icon_conf I have been unable to lower my kh/gh by much in my planted tank. my gh/kh lowers with water changes but immediately spikes back up. I have done several water changes with RO/DI water which is what finally lowered it to a gh of 9 and a kh of 11 but i cannot get it to budge from there. Also tried the brackish water treatment. It was cycled, have no ammonia, nitrate, or nitrite reading. PH is high at 7.4 consistently. All plants are thriving, fish just added yesterday after significant two month cycling.
Here is what I have:
37 gallon Dirt planted tank (sphagum peat moss layer, dirt layer, and sand above that)
various plants
drift wood
moss ball
peat moss on one filter, and and external filter for the charcoal, ammo carb, and purigen to keep water clean/clear
air bubbler
plant bulb in standard hood
Tetras, guppy, oto, and algae snails
what could i be missing?Have done tons of research but i have tried everything i have found outside of chemicals. trying to lower it naturally. Cannot use tap water has it is very hard water. Any guidance and assistance would be greatly appreciated. Thank

· Registered
43 Posts
I don't have advice really. My tap water is very hard as well. I have also been doing weekly wc with ro, and oi haven't seen much change... until the other day. It is still hard, and I haven't checked today to see if the changes stuck, but I changed substrate to soil, but had an emergency where the old 20 gallon aquarium I was using to hold some of the cycled water I wanted to reuse started leaking. I paniced and put the water back before I was ready. The result was sediment on all of the plants. So, I did water changes two days in a row. My gh dropped from 10 to around 3. KH dropped from 13 to 7. That's using 5 way test strips numbers aren't extremely accurate. After eight weeks of water changes, it was very exciting to finally see a change. My hypothesis is either larger water changes (like 50%) or more frequent water changes are more effective. I wouldn't have tried to do such big water changes if I had fish in the tank though since hard water is also pretty alkaline and ro is pretty acidic

· Registered
6 Posts
Discussion Starter · #7 ·
Substrate? It is peat moss, dirt, ecology plant substrate and sand over it. Layered. How would I change thatr without scrapping the tank or check it? Is there something I can add? Thought of adding clay but don't know where to find it.

· Administrator
17,898 Posts
Again, what are the parameters of your water?


What kind of kit are you using to test? If you're using a liquid kit to test your hardness, there really is no max.

And what kind of sand are you using? Depending upon the type, you could be impacting hardness with your sand.

· Registered
95 Posts
Use RO/DI water.... Its the only way.

Edit: if you have precipitate on your heater, filter etc, it could be getting absorbed back into the water.
Also test the RO/DI BEFORE you do anything with it. It may be time for new membranes.

If everything is thriving, why do you feel the need to mess with the chemistry?

Edit 2: Watch what you use to top off with. If you top off with buffered RO/DI then you will just be adding more and more carbonates to the water. Use un-molested RO/DI for top offs.

· Registered
6 Posts
Discussion Starter · #12 ·
Lowered KH, PH now GH is high?

So I did another RO/DI water change, added peat moss to the filter. Tested it with my API freshwater test kit. Added Seachem Acid buffer, and discuss buffer by recommendation of local aquarium store. Worked great for a bit Now my reading are
KH 6
GH 15
PH 6.6
No Nitrate
No Nitrite
No Ammonia

How to lower my GH? And Now i think my Guppies are pregnant as is my endler? Any thing I need to do for the pregnant fish and does anyone know how much time they incubate? Never had a pregnant fish before.
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