High PH, large tank, low stock

[stuhyde]

Looks like it might not have been the substrate after all.
Changed the substrate to basically raw gravel, also did a vinegar test to make sure.
Removed everything from the tank, plants disposed of as they were going black with algae
Done a 20% water change, few days later a 30% water change, then a 40% water change.
Now on day 3 approx, my pH is getting very high again, and the tank is going green very quickly.

Here's my process to help with any suggestions

Run my tap water (7pH) through a Nitrate removal system as my Nitrates are 40+ from the tap
Add Interpret Bioactive Tapsafe Plus in the required quantity
Top up with maybe half a litre of boiling water to get me around 24º which is what the tank is running at, and add to tank.
Tank pH is 7 or thereabouts at this point (raises to 8 when left for 48hrs)

Only thing it can be is my filter??? I have the Interpet Internal Corner Power Filter CPF3 and the tank is around 100L.
Also have 2 air stones at either side of the tank on low.

Any help appreciated as I'm at a bit of a loss now

 

[TwoTankAmin]

I think I have figured out your problem. PH is not an independant number. it is closely tied to KH which stand for carbonate hardeness. In our tanks KH pretty much comes from carbonates and bicarbonates. If you look at the very bottoms of your water report whichs deal with Hardness you will see a column for CaCo3 which is calcium carbonate. In water the calcium part contributes to GH whicle the carbonate part contributes to KH.

On the report they say your CaCo3 is 170 ppm. You can convert ppm to German degrees by dividing that number by 17.8. The result is you get over 9.5 degrees of KH. This is why you pH is rising. To confirm this you can bring a sample of your tap to your local fish store and they will test it, or you can buy the API GH/KH kit.

What follows comes from the FINS site.

Buffering Capacity (KH, Alkalinity)​

Buffering capacity refers to water's ability to keep the pHstable as acids or bases are added. pH and buffering capacity areintertwined with one another; although one might think that addingequal volumes of an acid and neutral water would result in a pHhalfway in between, this rarely happens in practice. If the water hassufficient buffering capacity, the buffering capacity can absorb andneutralize the added acid without significantly changing the pH.Conceptually, a buffer acts somewhat like a large sponge. As moreacid is added, the ``sponge'' absorbs the acid without changing the pHmuch. The ``sponge's'' capacity is limited however; once the bufferingcapacity is used up, the pH changes more rapidly as acids are added.
Buffering has both positive and negative consequences. On the plusside, the nitrogen cycle produces nitric acid (nitrate). Withoutbuffering, your tank's pH would drop over time (a bad thing). Withsufficient buffering, the pH stays stable (a good thing). On thenegative side, hard tap water often almost always has a largebuffering capacity. If the pH of the water is too high for your fish,the buffering capacity makes it difficult to lower the pH to a moreappropriate value. Naive attempts to change the pH of water usuallyfail because buffering effects are ignored.

In freshwater aquariums, most of water's buffering capacity is dueto carbonates and bicarbonates. Thus, the terms ``carbonate hardness''(KH), ``alkalinity'' and ``buffering capacity'' are used interchangeably.Although technically not the same things, they are equivalent inpractice in the context of fishkeeping. Note: the term ``alkalinity''should not be confused with the term ``alkaline''. Alkalinity refers tobuffering, while alkaline refers to a solution that is a base (i.e., pH> 7).

How much buffering does your tank need? Most aquarium bufferingcapacity test kits actually measure KH. The larger the KH, the moreresistant to pH changes your water will be. A tank's KH should be highenough to prevent large pH swings in your tank over time. If your KHis below roughly 4.5 dH, you should pay special attention to yourtank's pH (e.g, test weekly, until you get a feel for how stable thepH is). This is ESPECIALLY important if you neglect to do frequentpartial water changes. In particular, the nitrogen cycle createsa tendency for an established tank's pH to decrease over time. Theexact amount of pH change depends on the quantity and rate of nitratesproduced, as well as the KH. If your pH drops more than roughly twotenths of a point over a month, you should consider increasing the KHor performing partial water changes more frequently. KH doesn'taffect fish directly, so there is no need to match fish species to aparticular KH.

Note: it is not a good idea to use distilled water in your tank. Bydefinition, distilled water has essentially no KH. That means thatadding even a little bit of acid will change the pH significantly(stressing fish). Because of its instability, distilled (or anyessentially pure water) is never used directly. Tap water or othersalts must first be added to it in order to increase its GH and KH.

and

Raising and Lowering pH​

One can raise or lower pH by adding chemicals. Because ofbuffering, however, the process is difficult to get right. Increasingor decreasing the pH (in a stable way) actually involves changing theKH. The most common approach is to add a buffer (in the previoussection) whose equilibriumholds the pH at the desired value.
Muriatic (hydrochloric) acid can be used to reduce pH. Note thatthe exact quantity needed depends on the water's buffering capacity.In effect, you add enough acid to use up all the buffering capacity.Once this has been done, decreasing the pH is easy. However, it shouldbe noted that the resultant lower-pH water has much less KH bufferingthan it did before, making it more susceptible to pH swings when (for instance)nitrate levels rise. Warning: It goes without saying that acids areVERY dangerous! Do not use this approach unless you know whatyou are doing, and you should treat the water BEFORE adding itto the aquarium.

Products such as ``pH-Down'' are often based on a phosphoric acid buffer.Phosphoric acid tends to keep the pH at roughly 6.5, depending onhow much you use.Unfortunately, use of phosphoric acid has the BIG sideeffect of raising the phosphate level in your tank, stimulating algaegrowth. It is difficult to control algae growth in a tank withelevated phosphate levels.The only advantage over hydrochloric acid is that pH will be somewhatbetter buffered at its lower value.

One safe way to lower pH WITHOUT adjusting KH is to bubbleCO2 (carbon dioxide) through the tank. The CO2 dissolves in water, andsome of it forms carbonic acid. The formation of acid lowers the pH.Of course, in order for this approach to be practical, a steady sourceof CO2 bubbles (e.g. a CO2 tank) is needed to hold the pH inplace. As soon as the CO2 is gone, the pH bounces back to its previousvalue. The high cost of a CO2 injection system precludes its use as apH lowering technique in most aquariums (though see thePLANT FAQ for inexpensive do-it-yourselfalternatives). CO2 injection systemsare highly popular in heavily-planted tanks, because the additional CO2stimulates plant growth.

Also I would stop using the Interpret Bioactive Tapsafe Plus. It contains Aloe Vera which I will never put into any tank. It is felt that it has the potential to harm fish gills. It ca Next, there is no need to add more bacteria to a cycled tank unless you crash the bacterial colonies. So this is another reason not to use the product as your are paying for something you do not need. Perhaps you should consider changeing to a dechlor without these unneeded ingredients.

 

[stuhyde]

Thanks so much for the detailed response.
So assuming you are correct (which makes sense) is there anything I can do to lower the pH (or keep it from rising above 8 which is the max the tap water went to in a bowl) or just have high pH suitable fish?
I don’t want to be adding chemicals for obvious reasons, and other natural things only last for a short time.
RO water is not something I want to do, due to cost, adding back in minerals etc etc
Never had this problem 10 years ago when I did my 5ft tank.
Also is there anything that can keep algae at bay due to it being a high pH.
Cheers!!

 

[TwoTankAmin]

You can use RO water a lot cheaper than you think and you will not need to do more than mix it with your tap.

I have used RO/DI (even purer than just RO) for a number of years in a tank with Altum angels. I drop the pH from 7.0 from the tap to 6.0 in the tank. I am also dropping the TDS from about 83 ppm to 60 ppm at the same time.

Your tank a 105l = about 28 US gal. If you need to use a 50/50 mix you and you do a 50% water change weekly, you would change 14 gallons and 7 would be RO water. I started with 75 gallon/day 3 stage system- carbon-->RO-->DI, it makes pure water. The cost for this is $139 plus shipping. I need about 11 gallons/week. I batch it every 4-5 weeks and store 46.5 gallon in an assortment of containers. I had to repalce the RO and carbon after a few years. But I actually made more than just the 46 gallons.

During the winter my brother uses the same water in his small humidfiers during the colder months when the heating removes the moisture in the air. He uses about 3 gallons/day for about 4 months and somewhat less for another 2. If not for this the modules would have lasted me longer.

Have a look here for the system. My utiliy sink faucet was modified with a small piece that screws into it and allows me to attach any garden hose size connector to it. The system is dirt simple. I batch the water into a 20 gal. Rubbermaid heavy duty garbage can. from there I pump it into the storage containers.

Mikro Omega 3 Stage Portable Aquarium RO/DI System with 75 GPD Membrane

Portable 3-stage RO/DI system provides distilled quality water for reef aquariums and other ultra pure water applications on the go or in small living spaces

store.afwfilters.com

I take my unit with me when I would vend at weekend fish events. I needed to mix the hotel water 50/59 with my pure water. I have all of the Python faucet adapters so I can hook up my system in mu hotel bathroom to make more RO/DI water.

Consider that buying distilled water costs about $1/gal. I would guess I made a few well over 1,000 gallons before I had to change the 2 modules. Just 1,000 from that $139 unit works to 13.9 cents/gal. If it batches 1,500 that becomes 9.2 cents. In UK money that would be about 190 cents/gal. or less. Since you would need 7 gals/week that means your cost is about 70 pence/week at most and likely closer to 50p.

Bear in mind that that vendor is in the US, I do not know what your cost for something similar in the UK might be. But I cannot imagine it would be a whole lot more. At 139 US$ it would be £108.22.

 

[stuhyde]

You can use RO water a lot cheaper than you think and you will not need to do more than mix it with your tap.

I have used RO/DI (even purer than just RO) for a number of years in a tank with Altum angels. I drop the pH from 7.0 from the tap to 6.0 in the tank. I am also dropping the TDS from about 83 ppm to 60 ppm at the same time.

Your tank a 105l = about 28 US gal. If you need to use a 50/50 mix you and you do a 50% water change weekly, you would change 14 gallons and 7 would be RO water. I started with 75 gallon/day 3 stage system- carbon-->RO-->DI, it makes pure water. The cost for this is $139 plus shipping. I need about 11 gallons/week. I batch it every 4-5 weeks and store 46.5 gallon in an assortment of containers. I had to repalce the RO and carbon after a few years. But I actually made more than just the 46 gallons.

During the winter my brother uses the same water in his small humidfiers during the colder months when the heating removes the moisture in the air. He uses about 3 gallons/day for about 4 months and somewhat less for another 2. If not for this the modules would have lasted me longer.

Have a look here for the system. My utiliy sink faucet was modified with a small piece that screws into it and allows me to attach any garden hose size connector to it. The system is dirt simple. I batch the water into a 20 gal. Rubbermaid heavy duty garbage can. from there I pump it into the storage containers.


I take my unit with me when I would vend at weekend fish events. I needed to mix the hotel water 50/59 with my pure water. I have all of the Python faucet adapters so I can hook up my system in mu hotel bathroom to make more RO/DI water.

Consider that buying distilled water costs about $1/gal. I would guess I made a few well over 1,000 gallons before I had to change the 2 modules. Just 1,000 from that $139 unit works to 13.9 cents/gal. If it batches 1,500 that becomes 9.2 cents. In UK money that would be about 190 cents/gal. or less. Since you would need 7 gals/week that means your cost is about 70 pence/week at most and likely closer to 50p.

Bear in mind that that vendor is in the US, I do not know what your cost for something similar in the UK might be. But I cannot imagine it would be a whole lot more. At 139 US$ it would be £108.22.

Thanks TTA, I’ll take a look into it. Appreciate the response.

 

[Sleeveless]

I bought a RO system off Amazon. A 100gpd RO buddy for $85 and run it into a $25 trash can. Long term can be cost beneficial instead of buying each week as well. Best thing I ever did. My tank has finally been fairly stable. I keep my GH at 5 degrees and KH at 2 to 3. With that (using Seachem Alkaline buffer which is Sodium Bicarbonate and will also raise your PH higher) I get a PH from 7 to 7.6 swing over the 24 hours each day (using CO2 for plants). It took me a while, but had a bunch of issues adding to bad water quality and PH spikes. Lost a ton of fish, but now finally starting to enjoy the tank. Just have to deal with my new problem: pest snails lol...