Tebo said:
Would it be a bad thing to reduce the pipework from 25mm ? down to 22/17 on the FX5 ?
Yes, it would be an extremely bad thing. It would be so bad that it would completely defeat the purpose of buying an FX5 in the first place.
Tebo said:
I am assuming these reducers are available, my limited plumbing knowledge would make me think this would increase the water pressure coming out of the spray bar ? Reason I ask this is I have an external inline heater and also an inline CO2 diffuser that I would prefer to keep out of the tank if possible.
Try not to think that. Think instead of the extreme case, if for example, you were to reduce the diameter to zero. What would happen to the downstream pressure? Yes, the pressure would reduce to zero and the downstream flow would also reduce to zero. Therefore, as you approach a zero diameter you also approach a zero flow. Using a reducer on an FX5 will choke and suffocate the very same flow you would have spent your hard earned money to get. In general flow dynamics the smaller the cross sectional area the lower the pressure, the lower the flow and the higher the velocity. People see a higher velocity being squeezed out of a small restriction and they assume that this means a higher flow rate. But we are not interested necessarily in increasing the velocity of a small amount of water, we are interested in moving large masses of the fluid and that is best achieved by having as wide an area as possible, to allow more kilograms of fluid to move across a given point per second, even if the velocity of those kilograms is lower.
Tebo said:
The Eheim externals do seem quite high prices compared to the Fluval, the flow rates also don't seem to be relative to the price between both manufacturers. I am guessing the Eheim lph figures are more accurate and trustworthy rates for the units perhaps ? therefore not a like for like comparison. But the FX5 does seem to be more my price range. A second unit is also an option, just trying to workout the best way forward here.
No manufacturers claims of flow rate are accurate. That's because they measure and report the flow rate with almost zero head pressure and with no filter media inside the canister. The resulting numbers are always inflated, but our 10X rule is based on the manufacturer's rating because they all perform the same measurement trick, so that each unit can be compared directly. Our 10X rule takes into account the illusion of the filter ratings game.
In any case this is why I suggest that it would be better to use a second filter since you already have one filter in place. You would simply use a spraybar for each and the spraybar is already sized for the filter outputs. Then you combine the two spraybars across the back wall along the length of the tank. You can also feed gas directly into each of the two filter input tube grilles so that each filter will process CO2 into each of their respective spraybars. This gives even distribution of flow as well as even CO2 saturation across the tank. It is a more complicated setup but might be better value overall. If you decide to go with an FX5 then you should avoid reducers and fashion your own spraybar using plastic PVC tubing that fits the hose size.
Tebo said:
I started the 3 day blackout, I assume a blackout really is that, and I should cover the tank to remove any artificial light also, not that there is a lot where it is situated. As that is what I have done at this point.
Yes, Blackout means black. No light, no peeking, no feeding, no ambient light, no CO2. As black as black can be. Light triggers algae, therefore absence of light is the bane of algae.
Tebo said:
Also would my fertiliser have any impact on algae ? the one I was sold by the lfs was JBL Ferropol, but it seems reading on this site that an EI mix is a better route, and I see one of our site sponsors have starter kits for sale for this, would this be a more preferred method of adding fertilisers ?
Algae do not really care about fertilizers. They care about light. This is the reason people get into trouble in the first place, because they assume that nutrients cause algae so they don't feed the plants, they don't think about CO2 or flow and they use high light. So the result is that the plants starve to death and algae love it. If algae want to feast on fertilizer all they have to do is to feed on the rotting remains of the starving plants. I strongly suggest that you get the EI starter pack and that you stop listening to your LFS when it comes to the subject of plants. LFS may know about fish, puppies or frogs, but they typically don't know anything about plants. The EI starter pack will cost you 100X less than Ferropol. and will be 100X more effective.
Tebo said:
Also what media is recommended within the filter? would this have any impact on the algae ? currently there is a coarse foam, ceramic tubes and carbon in the three layers(default items that came in the filter kit). But again the more I read it seems Carbon isn't great when adding fertilisers, should this be removed, what should go in its place ?
Use any media you want. If you need to improve flow/distribution in the tank, which by the way, is 5000X more important than media type, then you can remove some of the media which significantly reduces hydrodynamic drag in the canister and improves flow throughput. Carbon is great and in fact it's so great that you can remove everything else in your canister and replace it with carbon. Carbon has very little effect on fertilizers and whatever effect it does have, so what? Just add more fertilizer and be done with it. Carbon does 100X more good things than bad things.
Tebo said:
The problem I have right now, there is too much information on this site and its difficult to know the right direction to move forward with it as to what is relevant to my situation.
That's why you need to go to the Tutorial section of the forum and read every article there. These are the summary of the basic truths that we have discovered over the years, and these procedures work well despite the propaganda published in many places such as in LFS.
Cheers,